IEC 60335-2-90:2015

IEC 60335-2-90 ®
Edition 4.1 2019-11
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –
Part 2-90: Particular requirements for commercial microwave ovens

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.

need further assistance, please contact the Customer Service

Centre: sales@iec.ch.
IEC 60335-2-90 ®
Edition 4.1 2019-11
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –

Part 2-90: Particular requirements for commercial microwave ovens

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 97.040.20 ISBN 978-2-8322-7630-3

IEC 60335-2-90 ®
Edition 4.1 2019-11
CONSOLIDATED VERSION
REDLINE VERSION
colour
inside
Household and similar electrical appliances – Safety –
Part 2-90: Particular requirements for commercial microwave ovens

– 2 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 9
3 Terms and definitions . 9
4 General requirement . 12
5 General conditions for the tests . 12
6 Classification . 13
7 Marking and instructions . 13
8 Protection against access to live parts . 15
9 Starting of motor-operated appliances . 15
10 Power input and current . 15
11 Heating . 15
12 Void . 16
13 Leakage current and electric strength at operating temperature . 16
14 Transient overvoltages . 16
15 Moisture resistance . 16
16 Leakage current and electric strength . 16
17 Overload protection of transformers and associated circuits . 17
18 Endurance . 17
19 Abnormal operation . 18
20 Stability and mechanical hazards . 20
21 Mechanical strength . 20
22 Construction . 22
23 Internal wiring . 27
24 Components . 27
25 Supply connection and external flexible cords . 28
26 Terminals for external conductors . 28
27 Provision for earthing . 29
28 Screws and connections . 29
29 Clearances, creepage distances and solid insulation . 29
30 Resistance to heat and fire . 29
31 Resistance to rusting . 29
32 Radiation, toxicity and similar hazards . 29
Annex A (informative) Routine tests . 31
Annex AA (normative) Combination microwave ovens . 33
Annex BB (normative) Requirements for commercial microwave ovens without a
cavity door and with conveyor-type means . 35
Annex CC (informative) Overview of the requirements for covers, means of access
and similar . 48
Annex DD (informative) Rationales for the microwave barrier and associated leakage
tests . 49

© IEC 2019
Annex EE (normative) Microwave ovens intended to be used on board ships . 55
Bibliography . 58

Figure 101 – Test rod for interlock concealment . 30
Figure BB.1 – Splash apparatus. 45
Figure BB.2 – Arrangement for measurement of microwave leakage from access
openings . 46
Figure BB.3 – Examples of definitions of Clause 3 and Clause BB.3 . 47

Table 101 – Number of potatoes . 19
Table BB.101 – Specifications for microwave barriers . 42

– 4 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – SAFETY –
Part 2-90: Particular requirements for commercial microwave ovens
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been prepared
for user convenience.
IEC 60335-2-90 edition 4.1 contains the fourth edition (2015-08) [documents 61B/529/FDIS and
61B/536/RVD] and its amendment 1 (2019-11) [documents 61B/618/CDV and 61B/631/RVC,
61B/619/CDV and 61B/632/RVC, 61B/617/CDV and 61B/633/RVC, 61B/616/CDV and 61B/634/RVC,
61B/612/CDV and 61B/635/RVC, 61B/620/CDV and 61B/636/RVC].
In this Redline version, a vertical line in the margin shows where the technical
content is modified by amendment 1. Additions are in green text, deletions are in
strikethrough red text. A separate Final version with all changes accepted is
available in this publication.

© IEC 2019
This part of International Standard IEC 60335 has been prepared by subcommittee 61B:
Safety of microwave appliances for household and commercial use, of IEC technical
committee 61: Safety of household and similar electrical appliances.
This fourth edition constitutes a technical revision.
The principal changes with respect to the previous edition are as follows (minor and editorial
changes are not listed):
– a statement in 7.12 is required for appliances intended to be used on commercial road
vehicles;
– a statement in 7.12 is required concerning cleaning of the appliance with a water jet;
– the replacement of 22.103, 22.104 and 22.105 allows interlock systems with at least one
concealed door interlock as well as alternative interlock systems without concealed door
interlock;
– requirements are added for appliances for installation in commercial road vehicles;
– an annex is added dealing with routine tests.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This Part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments. It was established on the basis of the fourth edition (2001) of that standard.
NOTE 1 When “Part 1” is mentioned in this standard, it refers to IEC 60335-1.
This Part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to
convert that publication into the IEC standard: Safety requirements for commercial microwave
ovens.
When a particular subclause of Part 1 is not mentioned in part 2, that subclause applies as far
as is reasonable. When this standard states "addition", "modification" or "replacement", the
relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold type in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and
the associated noun are also in bold.
The following differences exist in the countries indicated below.
– 5.3: Microwave leakage is not to exceed 10 W/m during the initial test (Japan,
USA and Canada).
– 6.1: Microwave ovens may be class OI if the rated voltage does not exceed more
than 150 V (Japan).
– 7.12: Some warnings have to be marked on the appliance and be visible to the
user (Canada).
– Clause 18: The test is carried out on two appliances (USA).

– 6 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
– 19.11.2: The input voltage variation is not applied (USA).
– 19.13: Microwave leakage is only measured at the end of each test (USA).
– 21.102: The applied force is 222 N (USA).
– 21.105: Microwave leakage is not to exceed 50 W/m (Japan and USA).
– 22.111: Microwave leakage is only measured at the end of the test (USA).
– 22.112: Microwave leakage is not to exceed 50 W/m (Japan and USA).
– 22.116: All access to the cavity has to be prevented (USA).
– 27.2: A terminal for an external equipotential conductor is not required (Japan).
A list of all parts of the IEC 60335 series, under the general title: Household and similar
electrical appliances – Safety, can be found on the IEC website.
The committee has decided that the contents of the base publication and its amendment will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
NOTE The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations can need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 12 months or later than 36 months from the date of publication.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
are considered to be useful for the correct
that it contains colours which
understanding of its contents. Users should therefore print this document using a
colour printer.
© IEC 2019
INTRODUCTION
It has been assumed in the drafting of this international standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in
normal use taking into account the manufacturer's instructions. It also covers abnormal
situations that can be expected in practice and takes into account the way in which
electromagnetic phenomena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that
there is compatibility with the wiring rules when the appliance is connected to the supply
mains. However, national wiring rules may differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into
account.
When a part 2 standard does not include additional requirements to cover hazards dealt with
in Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general
requirements.
This standard is a product family standard dealing with the safety of appliances and takes
precedence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal and generic standards covering a hazard are not applicable since they have been taken into
consideration when developing the general and particular requirements for the IEC 60335 series of standards. For
example, in the case of temperature requirements for surfaces on many appliances, generic standards, such as
ISO 13732-1 for hot surfaces, are not applicable in addition to Part 1 or part 2 standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features which impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of
the requirements and, if found to be substantially equivalent, may be considered to comply
with the standard.
– 8 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – SAFETY –

Part 2-90: Particular requirements for commercial microwave ovens

1 Scope
This clause of Part 1 is replaced by the following.
This International Standard deals with:
• the safety of microwave ovens with a cavity door intended for commercial use, their
rated voltage being not more than 250 V for single-phase appliances connected between
one phase and neutral and 480 V for other appliances;
• the safety of combination microwave ovens with a cavity door, the requirements for
which are contained in Annex AA;
• the safety of microwave ovens without a cavity door and with transportation means that
are intended for commercial use only, for the heating of food and beverages, the
requirements for which are contained in Annex BB.
Microwave ovens covered by Annex BB have transportation means for moving the load
through the microwave oven. Requirements for tunnel microwave ovens and several types of
microwave vending machines are covered.
This standard also deals with microwave ovens intended to be used on board ships, for
which Annex EE is applicable.
NOTE 101 In Annex BB, a microwave oven without a cavity door and with transportation means is described as
a microwave oven. All clauses of this standard apply to these appliances unless otherwise specified in Annex BB.
This international standard also takes into account ordinary persons having access to the
removing area of the vending machine.
NOTE 102 The appliance may be built into a vending machine, in which case IEC 60335-2-75 may also be
applicable.
NOTE 103 Appliances that use non-electrical energy are within the scope of this standard.
In general, this standard does not take into account
– the use of appliances by young children or infirm persons without supervision;
– playing with the appliance by young children.
This international standard does not take into account the use of a microwave oven without a
cavity door and with transportation means by ordinary persons except in the vicinity of
entrance and exit ports.
NOTE 104 The rationales for particular microwave exposure conditions and measures related to microwave
energy being confined by an open structure are in Annex BB.
NOTE 105 Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on trains, on board ships or board aircraft, additional
requirements may be necessary;
– for appliances intended to be used in tropical countries, special requirements may be necessary;
– in many countries, the national health authorities, the national authorities responsible for the protection of
labour and similar authorities specify additional requirements;
– in many countries, national authorities specify additional requirements to BB.22.119.1.

© IEC 2019
NOTE 106 This standard does not apply to
– household microwave ovens including combination microwave ovens (IEC 60335-2-25);
– industrial microwave heating equipment (IEC 60519-6);
– appliances for medical purposes (IEC 60601);
– appliances intended to be used in locations where special conditions prevail, such as the presence of a
corrosive or explosive atmosphere (dust, vapour or gas).
2 Normative references
This clause of Part 1 is applicable except as follows.
Addition:
IEC 60068-2-6, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-27, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 60068-2-52, Environmental testing – Part 2-52: Tests – Test Kb: Salt mist, cyclic (sodium
chloride solution)
IEC 60335-2-36, Household and similar electrical appliances – Safety – Part 2-36: Particular
requirements for commercial electric cooking ranges, ovens, hobs and hob elements
IEC 60335-2-42, Household and similar electrical appliances – Safety – Part 2-42: Particular
requirements for commercial electric forced convection ovens, steam cookers and steam-
convection ovens
IEC 60335-2-49, Household and similar electrical appliances – Safety – Part 2-49: Particular
requirements for commercial electric hot cupboards
IEC 60335-2-75, Household and similar electrical appliances – Safety – Part 2-75: Particular
requirements for commercial dispensing appliances and vending machines
IEC 60436:2004, Electric dishwashers for household use – Methods for measuring the
performance
IEC 60436:2004/AMD 1:2009
IEC 60436:2004/AMD 2:2012
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
3.1.7 Addition:
Note 101 to entry: The rated frequency is the input frequency.
3.1.9 Replacement:
normal operation
operation of the appliance under the following conditions:
The appliance is operated with 1 000 g ± 50 g of potable water at an initial temperature of
20 °C ± 2 °C in a cylindrical borosilicate glass vessel having a maximum thickness of 3 mm
and an outside diameter of approximately 190 mm. The vessel is placed on the centre of the
shelf. If the rated microwave power output exceeds 2 200 W, two such vessels are used
and placed contiguously in the cavity.

– 10 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
3.101
microwave oven
appliance using electromagnetic energy in one or several of the ISM frequency bands
between 300 MHz and 30 GHz, for heating food and beverages in a cavity
3.102
rated microwave power output
microwave power output assigned to the appliance by the manufacturer
3.103
cavity
space enclosed by the inner walls and the door in which the load is placed
3.104
shelf
horizontal support in the cavity on which the load is placed
3.105
door interlock
device or system that prevents the operation of the magnetron unless the oven door is closed
3.106
monitored door interlock
door interlock system that incorporates a supervision device
3.107
temperature-sensing probe
device that is inserted into the food to measure its temperature and is a part of an oven
control
3.108
instructed person
person who is sufficiently instructed and monitored to know how to avoid any danger caused
by the operation of microwave ovens
3.109
skilled person
person with suitable professional education, knowledge and experience to discern and to
avoid any danger caused by the operation of microwave ovens
3.110
ordinary person
person who is neither a skilled person nor an instructed person
3.111
transportation means
means to transport the load through the microwave oven
Note 1 to entry: An example of a transportation means is a belt, an arm or an inclined plane.
3.112
load
food and beverages that can be heated up in a microwave oven
___________
ISM frequency bands are the electromagnetic frequencies established by the ITU and reproduced in CISPR 11.

© IEC 2019
3.113
microwave enclosure
structure that is intended to confine microwave energy to a defined region
Note 1 to entry: Barriers mounted outside the microwave enclosure are not considered a part of the microwave
enclosure.
Note 2 to entry: A microwave enclosure may consist of a cavity, quarter wave chokes (acting by impedance
transformation), mode chokes (acting by field pattern mismatching) and microwave energy absorbers.
3.114
microwave barrier
physical barrier, which is microwave transparent, limiting access to the microwave
enclosure, mounted outside the microwave enclosure and can only be removed with the aid
of tools
Note 1 to entry: A microwave barrier may be mounted between the microwave enclosure and the external
cover of the appliance.
Note 2 to entry: Devices such as an array of metal chains or hinged metal plates at entrance and exit ports
intended to reduce microwave leakage are not considered microwave barriers.
Note 3 to entry: Construction requirements are given in BB.22.119.
3.115
entrance and exit ports
openings in the microwave enclosure through which loads move
3.116
loading area
area on which the load is placed
3.117
means of monitored microwave interlock
means of microwave interlock that incorporates a supervision device
3.118
protective blocking structure
movable mechanical structure located in the removing area limiting access to the microwave
enclosure
3.119
removing area
area from which the load is removed
3.120
viewing opening
opening in the cavity through which the warm up process can be visually monitored
3.121
fixed means of connection
all parts of the microwave enclosure that are permanently open with the exception of
entrance and exit ports and viewing openings
Note 1 to entry: Fixed means of connection may be used for venting and water flushing.
3.122
detachable means of access
all parts of the microwave enclosure that can be opened or removed without the aid of tools
to get access to the inside for maintenance, with the exception of entrance and exit ports
and viewing openings
– 12 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
Note 1 to entry: Examples of detachable means of access are tunnels that are opened by drop down or sliding
action and cavity lamp covers.
3.123
means of microwave interlock
mechanical or electrical safety devices or systems that operate when certain conditions are
not fulfilled (e.g. an interlock system that prevents the operation of the microwave generator
when a means of access is open)
3.124
maintenance cover
structural feature of any part of the equipment that can be opened or removed by the use of a
tool to provide access for routine maintenance, service, replacement of expendable parts, etc.
in microwave containing areas
3.125
cleaning cover
part of the microwave enclosure that can be opened or removed, only with the aid of a tool,
for frequent cleaning purposes, during operation
3.126
reference surface
surface in the vicinity of entrance and exits ports defined depending on the reading of
microwave leakage of Clause BB.32
Note 1 to entry: If the leakage reading is less or equal to 50 W/m , the reference surface is the surface of the
geometric opening of the microwave enclosure without microwave barrier.
Note 2 to entry: If the leakage reading exceeds 50 W/m , the reference surface is an artificial surface located
50 mm away from the locations where the sensor of the instrument measures leakage readings of 50 W/m straight
inwards towards the appliance.
Note 3 to entry: For further explanation, refer to Clause BB.32.
3.127
combination microwave oven
microwave oven in which heat is also provided in the cavity by simultaneous or consecutive
operation of resistive heating elements
Note 1 to entry: The resistive heating elements are used to provide radiant heat, convection heat or steam.
3.128
hot functional surface
surface that is intentionally heated by an internal heat source and that has to be hot to carry
out the intended function of the appliance
4 General requirement
This clause of Part 1 is applicable.
5 General conditions for the tests
This clause of Part 1 is applicable except as follows.
5.2 Addition:
NOTE 101 An additional sample may be required for the test of 19.104. Six samples of the interlocks are required
for the test of 24.1.4.
5.3 Modification:
© IEC 2019
Instead of carrying out the tests in the order of clauses, the following sequence of clauses
and subclauses applies: 32, 22.113, 22.108, 22.116, 7 to 17, 20, 21 (except 21.101 to
21.105), 18, 19 (except 19.104), 22 (except 22.108, 22.113 and 22.116), 23 to 31, 21.101 to
21.105 and 19.104.
5.101 Microwave ovens are tested as motor-operated appliances.
5.102 Class III temperature-sensing probes are only subjected to the tests of 22.112.
6 Classification
This clause of Part 1 is applicable except as follows.
6.1 Modification:
Microwave ovens shall be class I.
7 Marking and instructions
This clause of Part 1 is applicable except as follows.
7.1 Addition:
Appliances shall be marked with the nominal frequency in megahertz of the ISM band in which
they operate.
If the removal of any cover results in microwave leakage exceeding the value specified in
Clause 32, the cover shall be marked with the substance of the following:
WARNING: Microwave energy – Do not remove this cover
If an appliance incorporates a socket-outlet protected by means of fuses other than D-type
fuses, it shall be marked with the rated current of the relevant fuse. When a miniature fuse-
link is provided, this marking shall indicate that the fuse-link is to have a high breaking
capacity.
If appliances have external enclosures, other than working surfaces, that cannot meet the
limit in Table 3 specified for external enclosures of motor-operated appliances, they shall be
marked with symbol IEC 60417-5041(2002-10) or with the substance of the following:
CAUTION: Hot surface.
7.6 Addition:
[symbol IEC 60417-5021 (2002-10)] equipotentiality

[symbol IEC 60417-5041 (2002-10)] caution, hot surface

– 14 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
7.12 Addition:
The instructions shall include the substance of the following:
– WARNING: If the door or door seals are damaged, the oven must not be operated until it
has been repaired by a competent person;
– WARNING: It is hazardous for anyone other than a competent person to carry out any
service or repair operation that involves the removal of any cover which gives protection
against exposure to microwave energy;
– WARNING: Liquids or other foods must not be heated in sealed containers since they are
liable to explode;
– WARNING: Microwave heating of beverages can result in delayed eruptive boiling,
therefore care must be taken when handling the container;
– WARNING: The contents of feeding bottles and baby food jars must be stirred or shaken
and the temperature checked before consumption, in order to avoid burns;
– the minimum height of free space necessary above the top surface of the oven;
– only use utensils that are suitable for use in microwave ovens;
– when heating food in plastic or paper containers, keep an eye on the oven due to the
possibility of ignition;
– if smoke is observed, switch off or unplug the appliance and keep the door closed in order
to stifle any flames;
– eggs in their shell and whole hard-boiled eggs should not be heated in microwave ovens
since they may explode even after microwave heating has ended;
– details for cleaning door seals, cavities and adjacent parts;
– the oven should be cleaned regularly and any food deposits removed;
– failure to maintain the oven in a clean condition could lead to deterioration of the surface
that could adversely affect the life of the appliance and possibly result in a hazardous
situation;
– only use the temperature probe recommended for this oven (for appliances having a
facility to use a temperature-sensing probe);
– the appliance should not be cleaned with a water jet (for appliances intended to stand on
the floor and which are not at least IPX5);
– statement on usage on commercial road vehicles (for appliances intended to be used on
commercial road vehicles);
– the appliance must not be cleaned with a steam cleaner (for appliances which are not at
least IPX5).
NOTE 101 If the oven is incorporated in a vending machine, these warnings and instructions may not be relevant
and therefore not required.
7.14 Addition:
The warning specified in 7.1 shall be in lettering at least 3 mm high.
The warning specified in 7.101 shall be in lettering at least 5 mm high.
The height of the triangle used with symbol IEC 60417-5041 (2002-10) shall be at least
12 mm.
7.15 Addition:
© IEC 2019
The marking specified for hot surfaces shall be visible when the appliance is operated as in
normal use, including when actuating any switch, adjusting any control or opening a lid or
door. It shall not be placed on a hot functional surface.
7.101 A label shall be provided, together with instructions for fixing it in a conspicuous place
close to the appliance. The label shall state the substance of the following.
– WARNING: Liquids or other foods must not be heated in sealed containers since they are
liable to explode;
– WARNING: Microwave heating of beverages can result in delayed eruptive boiling,
therefore care must be taken when handling the container;
– WARNING: The contents of feeding bottles and baby food jars must be stirred or shaken
and the temperature checked before consumption, in order to avoid burns.
Compliance is checked by inspection.
8 Protection against access to live parts
This clause of Part 1 is applicable.
9 Starting of motor-operated appliances
This clause of Part 1 is not applicable.
10 Power input and current
This clause of Part 1 is applicable.
11 Heating
This clause of Part 1 is applicable except as follows.
11.2 Addition:
Appliances, other than built-in appliances, are positioned as specified for heating
appliances.
A ceiling is placed over the appliance at the minimum height stated in the instructions. The
ceiling has a depth of 300 mm from the back wall of the test corner and a length at least
150 mm in excess of the width of the appliance.
Appliances intended to be fixed to the floor, and appliances with a mass greater than 40 kg
and not provided with rollers, castors or similar means, are installed in accordance with the
installation instructions. If no instructions are supplied, these appliances are placed on the
floor as near as possible to the walls of the test corner.
11.7 Replacement:
Appliances are operated in cycles, each cycle consisting of a heating period of 4 min followed
by a rest period of 1 min until steady conditions are established. The last cycle does not
include a rest period of 1 min. Boiling water is added to the water load when half of the water

load has evaporated.
– 16 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
11.8 Addition:
The temperature rises of external surfaces are only measured on the surfaces that are not
placed against the wall and the floor of the test corner.
There are no temperature limits for air-outlet grilles and for surfaces up to a distance of
25 mm from them. When the required values for external enclosures of motor-operated
appliances are not met, the maximum temperature rise shall not be higher than two times the
values indicated.
12 Void
13 Leakage current and electric strength at operating temperature
This clause of Part 1 is applicable.
14 Transient overvoltages
This clause of Part 1 is applicable.
15 Moisture resistance
This clause of Part 1 is applicable except as follows.
15.2 Addition:
A quantity of 0,5 l of water containing approximately 1 % NaCl the same spillage solution is
poured steadily over the shelf over a period of 1 min. If the shelf can collect spilled liquid, it
is filled with the saline solution and a further 0,5 l is then added over a period of 1 min.
15.101 Temperature-sensing probes shall be constructed so that their insulation is not
affected by water.
Compliance is checked by the following test.
The probe is completely immersed in water containing approximately 1 % NaCl and having a
temperature of 20 °C ± 5 °C. The water solution is heated to the boiling point in approximately
15 min. The probe is then removed from the boiling water solution and immersed in water the
solution having a temperature of 20 °C ± 5 °C for 30 min.
This procedure is carried out five times, after which the probe is removed from the water
solution. All traces of liquid are then removed from the surface.
The probe shall then withstand the leakage current test of 16.2.
NOTE Detachable temperature-sensing probes are not connected to the appliance for this test. Non-
detachable temperature-sensing probes are tested in the oven cavity, the probe being immersed as much as
possible.
16 Leakage current and electric strength
This clause of Part 1 is applicable except as follows.

© IEC 2019
16.101 The windings of the power transformer that supplies the magnetron shall have
adequate insulation.
Compliance is checked by the test of 16.101.1 for switch-mode power supplies and by the test
of 16.101.2 for other power transformers.
16.101.1 The insulation between the primary and secondary windings of switch-mode power
supply transformers is subjected for 1 min to a voltage of substantially sinusoidal waveform
and having a frequency of 50 Hz or 60 Hz. The value of the voltage is 1,414 times the peak
value of the secondary working voltage plus 750 V, with a minimum of 1 250 V.
There shall be no breakdown between windings or between adjacent turns of the same
winding.
16.101.2 Twice the working voltage is induced in the secondary winding of the transformer
by applying a sinusoidal voltage having a frequency higher than rated frequency to the
primary terminals.
The duration of the test is
– 60 s, for frequencies up to twice the rated frequency, or
rated frequency
– 120 × s, with a minimum of 15 s, for higher frequencies.
test frequency
NOTE The frequency of the test voltage is higher than the rated frequency to avoid excessive excitation current.
A maximum of one-third of the test voltage is applied and is then rapidly increased without
creating transients. At the end of the test, the voltage is decreased in a similar manner to
approximately one-third of its full value before switching off.
There shall be no breakdown between windings or between adjacent turns of the same
winding.
17 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable except as follows.
Addition:
The tests are not carried out on the power transformer that supplies the magnetron and its
associated circuits, these are checked during the tests of Clause 19.
18 Endurance
This clause of Part 1 is replaced by the following.
The door system, including hinges, microwave seals and other associat
...

IEC 60335-2-90 ®
Edition 4.0 2015-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –
Part 2-90: Particular requirements for commercial microwave ovens

Appareils électrodomestiques et analogues – Sécurité –
Partie 2-90: Exigences particulières pour les fours à micro-ondes à usage
commercial
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient 21 000 termes et définitions en anglais
Spécifications techniques, Rapports techniques et autres
et en français, ainsi que les termes équivalents dans 16
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.

Recherche de publications IEC -
Glossaire IEC - std.iec.ch/glossary
webstore.iec.ch/advsearchform
67 000 entrées terminologiques électrotechniques, en anglais
La recherche avancée permet de trouver des publications IEC et en français, extraites des articles Termes et Définitions des
en utilisant différents critères (numéro de référence, texte, publications IEC parues depuis 2002. Plus certaines entrées
comité d’études,…). Elle donne aussi des informations sur les antérieures extraites des publications des CE 37, 77, 86 et
projets et les publications remplacées ou retirées. CISPR de l'IEC.

IEC Just Published - webstore.iec.ch/justpublished Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just Si vous désirez nous donner des commentaires sur cette
Published détaille les nouvelles publications parues. publication ou si vous avez des questions contactez-nous:
Disponible en ligne et aussi une fois par mois par email. sales@iec.ch.

IEC 60335-2-90 ®
Edition 4.0 2015-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –

Part 2-90: Particular requirements for commercial microwave ovens

Appareils électrodomestiques et analogues – Sécurité –

Partie 2-90: Exigences particulières pour les fours à micro-ondes à usage

commercial
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 97.040.20 ISBN 978-2-8322-6235-1

– 2 – IEC 60335-2-90:2015 © IEC 2015
CONTENTS
CONTENTS . 2
FOREWORD . 4
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 9
3 Definitions . 9
4 General requirement . 12
5 General conditions for the tests . 12
6 Classification . 13
7 Marking and instructions . 13
8 Protection against access to live parts . 15
9 Starting of motor-operated appliances . 15
10 Power input and current . 15
11 Heating . 15
12 Void . 16
13 Leakage current and electric strength at operating temperature . 16
14 Transient overvoltages . 16
15 Moisture resistance . 16
16 Leakage current and electric strength. 16
17 Overload protection of transformers and associated circuits . 17
18 Endurance . 17
19 Abnormal operation . 18
20 Stability and mechanical hazards . 19
21 Mechanical strength . 20
22 Construction . 22
23 Internal wiring . 26
24 Components . 26
25 Supply connection and external flexible cords . 27
26 Terminals for external conductors . 28
27 Provision for earthing . 28
28 Screws and connections . 28
29 Clearances, creepage distances and solid insulation . 28
30 Resistance to heat and fire . 28
31 Resistance to rusting . 28
32 Radiation, toxicity and similar hazards . 28
Annex A (informative) Routine tests. 30
Annex AA (normative) Combination microwave ovens . 32
Annex BB (normative) Requirements for commercial microwave ovens without a cavity
door and with conveyor-type means . 34
Annex CC (informative) Overview of the requirements for covers, means of access and
similar . 47
Annex DD (informative) Rationales for the microwave barrier and associated leakage tests . 48

Annex EE (normative) Microwave ovens intended to be used on board ships . 54
Bibliography . 57

Figure 101 – Test rod for interlock concealment . 29
Figure BB.1 – Splash apparatus . 44
Figure BB.2 – Arrangement for measurement of microwave leakage from access
openings . 45
Figure BB.3 – Examples of definitions of Clause 3 and Clause BB.3 . 46

Table 101 – Number of potatoes . 19
Table BB.101 – Specifications for microwave barriers . 41

– 4 – IEC 60335-2-90:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – SAFETY –

Part 2-90: Particular requirements for commercial microwave ovens

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This part of International Standard IEC 60335 has been prepared by subcommittee 61B: Safety
of microwave appliances for household and commercial use, of IEC technical committee 61:
Safety of household and similar electrical appliances.
This fourth edition cancels and replaces the third edition published in 2006 including its
Amendment 1 (2010) and Amendment 2 (2014). It constitutes a technical revision.
The principal changes with respect to the previous edition are as follows (minor and editorial
changes are not listed):
– a statement in 7.12 is required for appliances intended to be used on commercial road
vehicles;
– a statement in 7.12 is required concerning cleaning of the appliance with a water jet;
– the replacement of 22.103, 22.104 and 22.105 allows interlock systems with at least one
concealed door interlock as well as alternative interlock systems without concealed door
interlock;
– requirements are added for appliances for installation in commercial road vehicles;
– an annex is added dealing with routine tests.
This bilingual version (2018-11) corresponds to the monolingual English version, published in
2015-08.
The text of this standard is based on the following documents:
FDIS Report on voting
61B/529/FDIS 61B/536/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This Part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments. It was established on the basis of the fourth edition (2001) of that standard.
NOTE 1 When “Part 1” is mentioned in this standard, it refers to IEC 60335-1.
This Part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to
convert that publication into the IEC standard: Safety requirements for commercial microwave
ovens.
When a particular subclause of Part 1 is not mentioned in part 2, that subclause applies as far
as is reasonable. When this standard states "addition", "modification" or "replacement", the
relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold type in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and
the associated noun are also in bold.
The following differences exist in the countries indicated below.
– 5.3: Microwave leakage is not to exceed 10 W/m during the initial test (Japan,
USA and Canada).
– 6.1: Microwave ovens may be class OI if the rated voltage does not exceed more
than 150 V (Japan).
– 7.12: Some warnings have to be marked on the appliance and be visible to the
user (Canada).
– Clause 18: The test is carried out on two appliances (USA).
– 19.11.2: The input voltage variation is not applied (USA).

– 6 – IEC 60335-2-90:2015 © IEC 2015
– 19.13: Microwave leakage is only measured at the end of each test (USA).
– 21.102: The applied force is 222 N (USA).
– 21.105: Microwave leakage is not to exceed 50 W/m (Japan and USA).
– 22.111: Microwave leakage is only measured at the end of the test (USA).
– 22.112: Microwave leakage is not to exceed 50 W/m (Japan and USA).
– 22.116: All access to the cavity has to be prevented (USA).
– 27.2: A terminal for an external equipotential conductor is not required (Japan).
A list of all parts of the IEC 60335 series, under the general title: Household and similar
electrical appliances – Safety, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations can need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 12 months or later than 36 months from the date of publication.

INTRODUCTION
It has been assumed in the drafting of this international standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in normal
use taking into account the manufacturer's instructions. It also covers abnormal situations that
can be expected in practice and takes into account the way in which electromagnetic
phenomena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that
there is compatibility with the wiring rules when the appliance is connected to the supply mains.
However, national wiring rules may differ.
If an appliance within the scope of this standard also incorporates functions that are covered by
another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as far as
is reasonable. If applicable, the influence of one function on the other is taken into account.
When a part 2 standard does not include additional requirements to cover hazards dealt with in
Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general
requirements.
This standard is a product family standard dealing with the safety of appliances and takes
precedence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal and generic standards covering a hazard are not applicable since they have been taken into
consideration when developing the general and particular requirements for the IEC 60335 series of standards. For
example, in the case of temperature requirements for surfaces on many appliances, generic standards, such as
ISO 13732-1 for hot surfaces, are not applicable in addition to Part 1 or part 2 standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features which impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of the
requirements and, if found to be substantially equivalent, may be considered to comply with the
standard.
– 8 – IEC 60335-2-90:2015 © IEC 2015
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – SAFETY –

Part 2-90: Particular requirements for commercial microwave ovens

1 Scope
This clause of Part 1 is replaced by the following.
This International Standard deals with:
• the safety of microwave ovens with a cavity door intended for commercial use, their rated
voltage being not more than 250 V for single-phase appliances connected between one
phase and neutral and 480 V for other appliances;
• the safety of combination microwave ovens with a cavity door, the requirements for which
are contained in Annex AA;
• the safety of microwave ovens without a cavity door and with transportation means that
are intended for commercial use only, for the heating of food and beverages, the
requirements for which are contained in Annex BB.
Microwave ovens covered by Annex BB have transportation means for moving the load
through the microwave oven. Requirements for tunnel microwave ovens and several types of
microwave vending machines are covered.
This standard also deals with microwave ovens intended to be used on board ships, for which
Annex EE is applicable.
NOTE 101 In Annex BB, a microwave oven without a cavity door and with transportation means is described as a
microwave oven. All clauses of this standard apply to these appliances unless otherwise specified in Annex BB.
This international standard also takes into account ordinary persons having access to the
removing area of the vending machine.
NOTE 102 The appliance may be built into a vending machine, in which case IEC 60335-2-75 may also be
applicable.
NOTE 103 Appliances that use non-electrical energy are within the scope of this standard.
In general, this standard does not take into account
– the use of appliances by young children or infirm persons without supervision;
– playing with the appliance by young children.
This international standard does not take into account the use of a microwave oven without a
cavity door and with transportation means by ordinary persons except in the vicinity of
entrance and exit ports.
NOTE 104 The rationales for particular microwave exposure conditions and measures related to microwave energy
being confined by an open structure are in Annex BB.
NOTE 105 Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on board ships or aircraft, additional requirements may be
necessary;
– for appliances intended to be used in tropical countries, special requirements may be necessary;
– in many countries, the national health authorities, the national authorities responsible for the protection of
labour and similar authorities specify additional requirements;

– in many countries, national authorities specify additional requirements to BB.22.119.1.
NOTE 106 This standard does not apply to
– household microwave ovens including combination microwave ovens (IEC 60335-2-25);
– industrial microwave heating equipment (IEC 60519-6);
– appliances for medical purposes (IEC 60601);
– appliances intended to be used in locations where special conditions prevail, such as the presence of a
corrosive or explosive atmosphere (dust, vapour or gas).
2 Normative references
This clause of Part 1 is applicable except as follows.
Addition:
IEC 60068-2-6, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-27, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 60068-2-52, Environmental testing – Part 2-52: Tests – Test Kb: Salt mist, cyclic (sodium
chloride solution)
IEC 60436:2004, Electric dishwashers for household use – Methods for measuring the
performance
IEC 60436:2004/AMD 1:2009
IEC 60436:2004/AMD 2:2012
3 Definitions
This clause of Part 1 is applicable except as follows.
3.1.7 Addition:
Note 101 to entry: The rated frequency is the input frequency.
3.1.9 Replacement:
normal operation
operation of the appliance under the following conditions:
The appliance is operated with 1 000 g ± 50 g of potable water at an initial temperature of
20 °C ± 2 °C in a cylindrical borosilicate glass vessel having a maximum thickness of 3 mm
and an outside diameter of approximately 190 mm. The vessel is placed on the centre of the
shelf. If the rated microwave power output exceeds 2 200 W, two such vessels are used and
placed contiguously in the cavity.
3.101
microwave oven
appliance using electromagnetic energy in one or several of the ISM frequency bands between
300 MHz and 30 GHz, for heating food and beverages in a cavity
___________
ISM frequency bands are the electromagnetic frequencies established by the ITU and reproduced in CISPR 11.

– 10 – IEC 60335-2-90:2015 © IEC 2015
3.102
rated microwave power output
microwave power output assigned to the appliance by the manufacturer
3.103
cavity
space enclosed by the inner walls and the door in which the load is placed
3.104
shelf
horizontal support in the cavity on which the load is placed
3.105
door interlock
device or system that prevents the operation of the magnetron unless the oven door is closed
3.106
monitored door interlock
door interlock system that incorporates a supervision device
3.107
temperature-sensing probe
device that is inserted into the food to measure its temperature and is a part of an oven control
3.108
instructed person
person who is sufficiently instructed and monitored to know how to avoid any danger caused by
the operation of microwave ovens
3.109
skilled person
person with suitable professional education, knowledge and experience to discern and to avoid
any danger caused by the operation of microwave ovens
3.110
ordinary person
person who is neither a skilled person nor an instructed person
3.111
transportation means
means to transport the load through the microwave oven
Note 1 to entry: An example of a transportation means is a belt, an arm or an inclined plane.
3.112
load
food and beverages that can be heated up in a microwave oven
3.113
microwave enclosure
structure that is intended to confine microwave energy to a defined region
Note 1 to entry: Barriers mounted outside the microwave enclosure are not considered a part of the microwave
enclosure.
Note 2 to entry: A microwave enclosure may consist of a cavity, quarter wave chokes (acting by impedance
transformation), mode chokes (acting by field pattern mismatching) and microwave energy absorbers.

3.114
microwave barrier
physical barrier, which is microwave transparent, limiting access to the microwave enclosure,
mounted outside the microwave enclosure and can only be removed with the aid of tools
Note 1 to entry: A microwave barrier may be mounted between the microwave enclosure and the external
cover of the appliance.
Note 2 to entry: Devices such as an array of metal chains or hinged metal plates at entrance and exit ports
intended to reduce microwave leakage are not considered microwave barriers.
Note 3 to entry: Construction requirements are given in BB.22.119.
3.115
entrance and exit ports
openings in the microwave enclosure through which loads move
3.116
loading area
area on which the load is placed
3.117
means of monitored microwave interlock
means of microwave interlock that incorporates a supervision device
3.118
protective blocking structure
movable mechanical structure located in the removing area limiting access to the microwave
enclosure
3.119
removing area
area from which the load is removed
3.120
viewing opening
opening in the cavity through which the warm up process can be visually monitored
3.121
fixed means of connection
all parts of the microwave enclosure that are permanently open with the exception of
entrance and exit ports and viewing openings
Note 1 to entry: Fixed means of connection may be used for venting and water flushing.
3.122
detachable means of access
all parts of the microwave enclosure that can be opened or removed without the aid of tools
to get access to the inside for maintenance, with the exception of entrance and exit ports and
viewing openings
Note 1 to entry: Examples of detachable means of access are tunnels that are opened by drop down or sliding
action and cavity lamp covers.
3.123
means of microwave interlock
mechanical or electrical safety devices or systems that operate when certain conditions are not
fulfilled (e.g. an interlock system that prevents the operation of the microwave generator when
a means of access is open)
– 12 – IEC 60335-2-90:2015 © IEC 2015
3.124
maintenance cover
structural feature of any part of the equipment that can be opened or removed by the use of a
tool to provide access for routine maintenance, service, replacement of expendable parts, etc.
in microwave containing areas
3.125
cleaning cover
part of the microwave enclosure that can be opened or removed, only with the aid of a tool,
for frequent cleaning purposes, during operation
3.126
reference surface
surface in the vicinity of entrance and exits ports defined depending on the reading of
microwave leakage of Clause BB.32
Note 1 to entry: If the leakage reading is less or equal to 50 W/m , the reference surface is the surface of the
geometric opening of the microwave enclosure without microwave barrier.
Note 2 to entry: If the leakage reading exceeds 50 W/m , the reference surface is an artificial surface located
50 mm away from the locations where the sensor of the instrument measures leakage readings of 50 W/m straight
inwards towards the appliance.
Note 3 to entry: For further explanation, refer to Clause BB.32.
3.127
combination microwave oven
microwave oven in which heat is also provided in the cavity by simultaneous or consecutive
operation of resistive heating elements
Note 1 to entry: The resistive heating elements are used to provide radiant heat, convection heat or steam.
3.128
hot functional surface
surface that is intentionally heated by an internal heat source and that has to be hot to carry
out the intended function of the appliance
4 General requirement
This clause of Part 1 is applicable.
5 General conditions for the tests
This clause of Part 1 is applicable except as follows.
5.2 Addition:
NOTE 101 An additional sample may be required for the test of 19.104. Six samples of the interlocks are required
for the test of 24.1.4.
5.3 Modification:
Instead of carrying out the tests in the order of clauses, the following sequence of clauses and
subclauses applies: 32, 22.113, 22.108, 22.116, 7 to 17, 20, 21 (except 21.101 to 21.105), 18,
19 (except 19.104), 22 (except 22.108, 22.113 and 22.116), 23 to 31, 21.101 to 21.105 and
19.104.
5.101 Microwave ovens are tested as motor-operated appliances.

5.102 Class III temperature-sensing probes are only subjected to the tests of 22.112.
6 Classification
This clause of Part 1 is applicable except as follows.
6.1 Modification:
Microwave ovens shall be class I.
7 Marking and instructions
This clause of Part 1 is applicable except as follows.
7.1 Addition:
Appliances shall be marked with the nominal frequency in megahertz of the ISM band in which
they operate.
If the removal of any cover results in microwave leakage exceeding the value specified in
Clause 32, the cover shall be marked with the substance of the following:
WARNING: Microwave energy – Do not remove this cover
If an appliance incorporates a socket-outlet protected by means of fuses other than D-type
fuses, it shall be marked with the rated current of the relevant fuse. When a miniature fuse-link
is provided, this marking shall indicate that the fuse-link is to have a high breaking capacity.
If appliances have external enclosures, other than working surfaces, that cannot meet the limit
in Table 3 specified for external enclosures of motor-operated appliances, they shall be
marked with symbol IEC 60417-5041(2002-10) or with the substance of the following:
CAUTION: Hot surface.
7.6 Addition:
[symbol IEC 60417-5021 (2002-10)] equipotentiality

[symbol IEC 60417-5041 (2002-10)] caution, hot surface

7.12 Addition:
The instructions shall include the substance of the following:
– WARNING: If the door or door seals are damaged, the oven must not be operated until it
has been repaired by a competent person;
– WARNING: It is hazardous for anyone other than a competent person to carry out any
service or repair operation that involves the removal of any cover which gives protection
against exposure to microwave energy;

– 14 – IEC 60335-2-90:2015 © IEC 2015
– WARNING: Liquids or other foods must not be heated in sealed containers since they are
liable to explode;
– WARNING: Microwave heating of beverages can result in delayed eruptive boiling,
therefore care must be taken when handling the container;
– WARNING: The contents of feeding bottles and baby food jars must be stirred or shaken
and the temperature checked before consumption, in order to avoid burns;
– the minimum height of free space necessary above the top surface of the oven;
– only use utensils that are suitable for use in microwave ovens;
– when heating food in plastic or paper containers, keep an eye on the oven due to the
possibility of ignition;
– if smoke is observed, switch off or unplug the appliance and keep the door closed in order
to stifle any flames;
– eggs in their shell and whole hard-boiled eggs should not be heated in microwave ovens
since they may explode even after microwave heating has ended;
– details for cleaning door seals, cavities and adjacent parts;
– the oven should be cleaned regularly and any food deposits removed;
– failure to maintain the oven in a clean condition could lead to deterioration of the surface
that could adversely affect the life of the appliance and possibly result in a hazardous
situation;
– only use the temperature probe recommended for this oven (for appliances having a facility
to use a temperature-sensing probe);
– the appliance should not be cleaned with a water jet (for appliances intended to stand on
the floor and which are not at least IPX5);
– statement on usage on commercial road vehicles (for appliances intended to be used on
commercial road vehicles);
– the appliance must not be cleaned with a steam cleaner (for appliances which are not at
least IPX5).
NOTE 101 If the oven is incorporated in a vending machine, these warnings and instructions may not be relevant
and therefore not required.
7.14 Addition:
The warning specified in 7.1 shall be in lettering at least 3 mm high.
The warning specified in 7.101 shall be in lettering at least 5 mm high.
The height of the triangle used with symbol IEC 60417-5041 (2002-10) shall be at least 12 mm.
7.15 Addition:
The marking specified for hot surfaces shall be visible when the appliance is operated as in
normal use, including when actuating any switch, adjusting any control or opening a lid or door.
It shall not be placed on a hot functional surface.
7.101 A label shall be provided, together with instructions for fixing it in a conspicuous place
close to the appliance. The label shall state the substance of the following.
– WARNING: Liquids or other foods must not be heated in sealed containers since they are
liable to explode;
– WARNING: Microwave heating of beverages can result in delayed eruptive boiling,
therefore care must be taken when handling the container;

– WARNING: The contents of feeding bottles and baby food jars must be stirred or shaken
and the temperature checked before consumption, in order to avoid burns.
Compliance is checked by inspection.
8 Protection against access to live parts
This clause of Part 1 is applicable.
9 Starting of motor-operated appliances
This clause of Part 1 is not applicable.
10 Power input and current
This clause of Part 1 is applicable.
11 Heating
This clause of Part 1 is applicable except as follows.
11.2 Addition:
Appliances, other than built-in appliances, are positioned as specified for heating
appliances.
A ceiling is placed over the appliance at the minimum height stated in the instructions. The
ceiling has a depth of 300 mm from the back wall of the test corner and a length at least
150 mm in excess of the width of the appliance.
Appliances intended to be fixed to the floor, and appliances with a mass greater than 40 kg and
not provided with rollers, castors or similar means, are installed in accordance with the
installation instructions. If no instructions are supplied, these appliances are placed on the floor
as near as possible to the walls of the test corner.
11.7 Replacement:
Appliances are operated in cycles, each cycle consisting of a heating period of 4 min followed
by a rest period of 1 min until steady conditions are established. Boiling water is added to the
water load when half of the water load has evaporated.
11.8 Addition:
The temperature rises of external surfaces are only measured on the surfaces that are not
placed against the wall and the floor of the test corner.
There are no temperature limits for air-outlet grilles and for surfaces up to a distance of 25 mm
from them. When the required values for external enclosures of motor-operated appliances
are not met, the maximum temperature rise shall not be higher than two times the values
indicated.
– 16 – IEC 60335-2-90:2015 © IEC 2015
12 Void
13 Leakage current and electric strength at operating temperature
This clause of Part 1 is applicable.
14 Transient overvoltages
This clause of Part 1 is applicable.
15 Moisture resistance
This clause of Part 1 is applicable except as follows.
15.2 Addition:
A quantity of 0,5 l of water containing approximately 1 % NaCl is poured steadily over the shelf
over a period of 1 min. If the shelf can collect spilled liquid, it is filled with the saline solution
and a further 0,5 l is then added over a period of 1 min.
15.101 Temperature-sensing probes shall be constructed so that their insulation is not
affected by water.
Compliance is checked by the following test.
The probe is completely immersed in water containing approximately 1 % NaCl and having a
± 5 °C. The water is heated to the boiling point in approximately 15 min.
temperature of 20 °C
The probe is then removed from the boiling water and immersed in water having a temperature
of 20 °C ± 5 °C for 30 min.
This procedure is carried out five times, after which the probe is removed from the water. All
traces of liquid are then removed from the surface.
The probe shall then withstand the leakage current test of 16.2.
NOTE Detachable temperature-sensing probes are not connected to the appliance for this test. Non-
detachable temperature-sensing probes are tested in the oven, the probe being immersed as much as possible.
16 Leakage current and electric strength
This clause of Part 1 is applicable except as follows.
16.101 The windings of the power transformer that supplies the magnetron shall have
adequate insulation.
Compliance is checked by the test of 16.101.1 for switch-mode power supplies and by the test
of 16.101.2 for other power transformers.
16.101.1 The insulation between the primary and secondary windings of switch-mode power
supply transformers is subjected for 1 min to a voltage of substantially sinusoidal waveform
and having a frequency of 50 Hz or 60 Hz. The value of the voltage is 1,414 times the peak
value of the secondary working voltage plus 750 V, with a min
...

IEC 60335-2-90 ®
Edition 4.1 2019-11
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Household and similar electrical appliances – Safety –
Part 2-90: Particular requirements for commercial microwave ovens

Appareils électrodomestiques et analogues – Sécurité –
Partie 2-90: Exigences particulières pour les fours à micro-ondes à usage
commercial
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform IEC online collection - oc.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always
committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 000 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 18 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.
A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.
IEC online collection - oc.iec.ch
Recherche de publications IEC -
webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez
La recherche avancée permet de trouver des publications IEC gratuitement tous les aperçus des publications. Avec un
en utilisant différents critères (numéro de référence, texte, abonnement, vous aurez toujours accès à un contenu à jour
comité d’études, …). Elle donne aussi des informations sur adapté à vos besoins.
les projets et les publications remplacées ou retirées.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
Le premier dictionnaire d'électrotechnologie en ligne au
Restez informé sur les nouvelles publications IEC. Just
monde, avec plus de 22 000 articles terminologiques en
Published détaille les nouvelles publications parues.
anglais et en français, ainsi que les termes équivalents dans
Disponible en ligne et une fois par mois par email.
16 langues additionnelles. Egalement appelé Vocabulaire
Electrotechnique International (IEV) en ligne.
Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
IEC 60335-2-90 ®
Edition 4.1 2019-11
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Household and similar electrical appliances – Safety –
Part 2-90: Particular requirements for commercial microwave ovens
Appareils électrodomestiques et analogues – Sécurité –
Partie 2-90: Exigences particulières pour les fours à micro-ondes à usage
commercial
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 97.040.20 ISBN 978-2-8322-4133-2

IEC 60335-2-90 ®
Edition 4.1 2019-11
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Household and similar electrical appliances – Safety –
Part 2-90: Particular requirements for commercial microwave ovens

Appareils électrodomestiques et analogues – Sécurité –
Partie 2-90: Exigences particulières pour les fours à micro-ondes à usage
commercial
– 2 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 9
3 Terms and definitions . 9
4 General requirement . 12
5 General conditions for the tests . 12
6 Classification . 13
7 Marking and instructions . 13
8 Protection against access to live parts . 15
9 Starting of motor-operated appliances . 15
10 Power input and current . 15
11 Heating . 15
12 Void . 16
13 Leakage current and electric strength at operating temperature . 16
14 Transient overvoltages . 16
15 Moisture resistance . 16
16 Leakage current and electric strength . 16
17 Overload protection of transformers and associated circuits . 17
18 Endurance . 17
19 Abnormal operation . 18
20 Stability and mechanical hazards . 20
21 Mechanical strength . 20
22 Construction . 22
23 Internal wiring . 27
24 Components . 27
25 Supply connection and external flexible cords . 28
26 Terminals for external conductors . 28
27 Provision for earthing . 29
28 Screws and connections . 29
29 Clearances, creepage distances and solid insulation . 29
30 Resistance to heat and fire . 29
31 Resistance to rusting . 29
32 Radiation, toxicity and similar hazards . 29
Annex A (informative) Routine tests . 31
Annex AA (normative) Combination microwave ovens . 33
Annex BB (normative) Requirements for commercial microwave ovens without a
cavity door and with conveyor-type means . 35
Annex CC (informative) Overview of the requirements for covers, means of access
and similar . 48
Annex DD (informative) Rationales for the microwave barrier and associated leakage
tests . 49

© IEC 2019
Annex EE (normative) Microwave ovens intended to be used on board ships . 55
Bibliography . 58

Figure 101 – Test rod for interlock concealment . 30
Figure BB.1 – Splash apparatus. 45
Figure BB.2 – Arrangement for measurement of microwave leakage from access
openings . 46
Figure BB.3 – Examples of definitions of Clause 3 and Clause BB.3 . 47

Table 101 – Number of potatoes . 19
Table BB.101 – Specifications for microwave barriers . 42

– 4 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – SAFETY –

Part 2-90: Particular requirements for commercial microwave ovens

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 60335-2-90 edition 4.1 contains the fourth edition (2015-08) [documents
61B/529/FDIS and 61B/536/RVD] and its amendment 1 (2019-11) [documents
61B/618/CDV and 61B/631/RVC, 61B/619/CDV and 61B/632/RVC, 61B/617/CDV and
61B/633/RVC, 61B/616/CDV and 61B/634/RVC, 61B/612/CDV and 61B/635/RVC,
61B/620/CDV and 61B/636/RVC].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
© IEC 2019
This part of International Standard IEC 60335 has been prepared by subcommittee 61B:
Safety of microwave appliances for household and commercial use, of IEC technical
committee 61: Safety of household and similar electrical appliances.
This fourth edition constitutes a technical revision.
The principal changes with respect to the previous edition are as follows (minor and editorial
changes are not listed):
– a statement in 7.12 is required for appliances intended to be used on commercial road
vehicles;
– a statement in 7.12 is required concerning cleaning of the appliance with a water jet;
– the replacement of 22.103, 22.104 and 22.105 allows interlock systems with at least one
concealed door interlock as well as alternative interlock systems without concealed door
interlock;
– requirements are added for appliances for installation in commercial road vehicles;
– an annex is added dealing with routine tests.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This Part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments. It was established on the basis of the fourth edition (2001) of that standard.
NOTE 1 When “Part 1” is mentioned in this standard, it refers to IEC 60335-1.
This Part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to
convert that publication into the IEC standard: Safety requirements for commercial microwave
ovens.
When a particular subclause of Part 1 is not mentioned in part 2, that subclause applies as far
as is reasonable. When this standard states "addition", "modification" or "replacement", the
relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold type in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and
the associated noun are also in bold.
The following differences exist in the countries indicated below.
– 5.3: Microwave leakage is not to exceed 10 W/m during the initial test (Japan,
USA and Canada).
– 6.1: Microwave ovens may be class OI if the rated voltage does not exceed more
than 150 V (Japan).
– 7.12: Some warnings have to be marked on the appliance and be visible to the
user (Canada).
– Clause 18: The test is carried out on two appliances (USA).

– 6 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
– 19.11.2: The input voltage variation is not applied (USA).
– 19.13: Microwave leakage is only measured at the end of each test (USA).
– 21.102: The applied force is 222 N (USA).
– 21.105: Microwave leakage is not to exceed 50 W/m (Japan and USA).
– 22.111: Microwave leakage is only measured at the end of the test (USA).
– 22.112: Microwave leakage is not to exceed 50 W/m (Japan and USA).
– 22.116: All access to the cavity has to be prevented (USA).
– 27.2: A terminal for an external equipotential conductor is not required (Japan).
A list of all parts of the IEC 60335 series, under the general title: Household and similar
electrical appliances – Safety, can be found on the IEC website.
The committee has decided that the contents of the base publication and its amendment will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations can need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 12 months or later than 36 months from the date of publication.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
© IEC 2019
INTRODUCTION
It has been assumed in the drafting of this international standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in
normal use taking into account the manufacturer's instructions. It also covers abnormal
situations that can be expected in practice and takes into account the way in which
electromagnetic phenomena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that
there is compatibility with the wiring rules when the appliance is connected to the supply
mains. However, national wiring rules may differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into
account.
When a part 2 standard does not include additional requirements to cover hazards dealt with
in Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general
requirements.
This standard is a product family standard dealing with the safety of appliances and takes
precedence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal and generic standards covering a hazard are not applicable since they have been taken into
consideration when developing the general and particular requirements for the IEC 60335 series of standards. For
example, in the case of temperature requirements for surfaces on many appliances, generic standards, such as
ISO 13732-1 for hot surfaces, are not applicable in addition to Part 1 or part 2 standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features which impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of
the requirements and, if found to be substantially equivalent, may be considered to comply
with the standard.
– 8 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – SAFETY –

Part 2-90: Particular requirements for commercial microwave ovens

1 Scope
This clause of Part 1 is replaced by the following.
This International Standard deals with:
• the safety of microwave ovens with a cavity door intended for commercial use, their
rated voltage being not more than 250 V for single-phase appliances connected between
one phase and neutral and 480 V for other appliances;
• the safety of combination microwave ovens with a cavity door, the requirements for
which are contained in Annex AA;
• the safety of microwave ovens without a cavity door and with transportation means that
are intended for commercial use only, for the heating of food and beverages, the
requirements for which are contained in Annex BB.
Microwave ovens covered by Annex BB have transportation means for moving the load
through the microwave oven. Requirements for tunnel microwave ovens and several types of
microwave vending machines are covered.
This standard also deals with microwave ovens intended to be used on board ships, for
which Annex EE is applicable.
NOTE 101 In Annex BB, a microwave oven without a cavity door and with transportation means is described as
a microwave oven. All clauses of this standard apply to these appliances unless otherwise specified in Annex BB.
This international standard also takes into account ordinary persons having access to the
removing area of the vending machine.
NOTE 102 The appliance may be built into a vending machine, in which case IEC 60335-2-75 may also be
applicable.
NOTE 103 Appliances that use non-electrical energy are within the scope of this standard.
In general, this standard does not take into account
– the use of appliances by young children or infirm persons without supervision;
– playing with the appliance by young children.
This international standard does not take into account the use of a microwave oven without a
cavity door and with transportation means by ordinary persons except in the vicinity of
entrance and exit ports.
NOTE 104 The rationales for particular microwave exposure conditions and measures related to microwave
energy being confined by an open structure are in Annex BB.
NOTE 105 Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on trains, on board ships or board aircraft, additional
requirements may be necessary;
– for appliances intended to be used in tropical countries, special requirements may be necessary;
– in many countries, the national health authorities, the national authorities responsible for the protection of
labour and similar authorities specify additional requirements;
– in many countries, national authorities specify additional requirements to BB.22.119.1.

© IEC 2019
NOTE 106 This standard does not apply to
– household microwave ovens including combination microwave ovens (IEC 60335-2-25);
– industrial microwave heating equipment (IEC 60519-6);
– appliances for medical purposes (IEC 60601);
– appliances intended to be used in locations where special conditions prevail, such as the presence of a
corrosive or explosive atmosphere (dust, vapour or gas).
2 Normative references
This clause of Part 1 is applicable except as follows.
Addition:
IEC 60068-2-6, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-27, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 60068-2-52, Environmental testing – Part 2-52: Tests – Test Kb: Salt mist, cyclic (sodium
chloride solution)
IEC 60335-2-36, Household and similar electrical appliances – Safety – Part 2-36: Particular
requirements for commercial electric cooking ranges, ovens, hobs and hob elements
IEC 60335-2-42, Household and similar electrical appliances – Safety – Part 2-42: Particular
requirements for commercial electric forced convection ovens, steam cookers and steam-
convection ovens
IEC 60335-2-49, Household and similar electrical appliances – Safety – Part 2-49: Particular
requirements for commercial electric hot cupboards
IEC 60335-2-75, Household and similar electrical appliances – Safety – Part 2-75: Particular
requirements for commercial dispensing appliances and vending machines
IEC 60436:2004, Electric dishwashers for household use – Methods for measuring the
performance
IEC 60436:2004/AMD 1:2009
IEC 60436:2004/AMD 2:2012
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
3.1.7 Addition:
Note 101 to entry: The rated frequency is the input frequency.
3.1.9 Replacement:
normal operation
operation of the appliance under the following conditions:
The appliance is operated with 1 000 g ± 50 g of potable water at an initial temperature of
20 °C ± 2 °C in a cylindrical borosilicate glass vessel having a maximum thickness of 3 mm
and an outside diameter of approximately 190 mm. The vessel is placed on the centre of the
shelf. If the rated microwave power output exceeds 2 200 W, two such vessels are used
and placed contiguously in the cavity.

– 10 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
3.101
microwave oven
appliance using electromagnetic energy in one or several of the ISM frequency bands
between 300 MHz and 30 GHz, for heating food and beverages in a cavity
3.102
rated microwave power output
microwave power output assigned to the appliance by the manufacturer
3.103
cavity
space enclosed by the inner walls and the door in which the load is placed
3.104
shelf
horizontal support in the cavity on which the load is placed
3.105
door interlock
device or system that prevents the operation of the magnetron unless the oven door is closed
3.106
monitored door interlock
door interlock system that incorporates a supervision device
3.107
temperature-sensing probe
device that is inserted into the food to measure its temperature and is a part of an oven
control
3.108
instructed person
person who is sufficiently instructed and monitored to know how to avoid any danger caused
by the operation of microwave ovens
3.109
skilled person
person with suitable professional education, knowledge and experience to discern and to
avoid any danger caused by the operation of microwave ovens
3.110
ordinary person
person who is neither a skilled person nor an instructed person
3.111
transportation means
means to transport the load through the microwave oven
Note 1 to entry: An example of a transportation means is a belt, an arm or an inclined plane.
3.112
load
food and beverages that can be heated up in a microwave oven
___________
ISM frequency bands are the electromagnetic frequencies established by the ITU and reproduced in CISPR 11.

© IEC 2019
3.113
microwave enclosure
structure that is intended to confine microwave energy to a defined region
Note 1 to entry: Barriers mounted outside the microwave enclosure are not considered a part of the microwave
enclosure.
Note 2 to entry: A microwave enclosure may consist of a cavity, quarter wave chokes (acting by impedance
transformation), mode chokes (acting by field pattern mismatching) and microwave energy absorbers.
3.114
microwave barrier
physical barrier, which is microwave transparent, limiting access to the microwave
enclosure, mounted outside the microwave enclosure and can only be removed with the aid
of tools
Note 1 to entry: A microwave barrier may be mounted between the microwave enclosure and the external
cover of the appliance.
Note 2 to entry: Devices such as an array of metal chains or hinged metal plates at entrance and exit ports
intended to reduce microwave leakage are not considered microwave barriers.
Note 3 to entry: Construction requirements are given in BB.22.119.
3.115
entrance and exit ports
openings in the microwave enclosure through which loads move
3.116
loading area
area on which the load is placed
3.117
means of monitored microwave interlock
means of microwave interlock that incorporates a supervision device
3.118
protective blocking structure
movable mechanical structure located in the removing area limiting access to the microwave
enclosure
3.119
removing area
area from which the load is removed
3.120
viewing opening
opening in the cavity through which the warm up process can be visually monitored
3.121
fixed means of connection
all parts of the microwave enclosure that are permanently open with the exception of
entrance and exit ports and viewing openings
Note 1 to entry: Fixed means of connection may be used for venting and water flushing.
3.122
detachable means of access
all parts of the microwave enclosure that can be opened or removed without the aid of tools
to get access to the inside for maintenance, with the exception of entrance and exit ports
and viewing openings
– 12 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
Note 1 to entry: Examples of detachable means of access are tunnels that are opened by drop down or sliding
action and cavity lamp covers.
3.123
means of microwave interlock
mechanical or electrical safety devices or systems that operate when certain conditions are
not fulfilled (e.g. an interlock system that prevents the operation of the microwave generator
when a means of access is open)
3.124
maintenance cover
structural feature of any part of the equipment that can be opened or removed by the use of a
tool to provide access for routine maintenance, service, replacement of expendable parts, etc.
in microwave containing areas
3.125
cleaning cover
part of the microwave enclosure that can be opened or removed, only with the aid of a tool,
for frequent cleaning purposes, during operation
3.126
reference surface
surface in the vicinity of entrance and exits ports defined depending on the reading of
microwave leakage of Clause BB.32
Note 1 to entry: If the leakage reading is less or equal to 50 W/m , the reference surface is the surface of the
geometric opening of the microwave enclosure without microwave barrier.
Note 2 to entry: If the leakage reading exceeds 50 W/m , the reference surface is an artificial surface located
50 mm away from the locations where the sensor of the instrument measures leakage readings of 50 W/m straight
inwards towards the appliance.
Note 3 to entry: For further explanation, refer to Clause BB.32.
3.127
combination microwave oven
microwave oven in which heat is also provided in the cavity by simultaneous or consecutive
operation of resistive heating elements
Note 1 to entry: The resistive heating elements are used to provide radiant heat, convection heat or steam.
3.128
hot functional surface
surface that is intentionally heated by an internal heat source and that has to be hot to carry
out the intended function of the appliance
4 General requirement
This clause of Part 1 is applicable.
5 General conditions for the tests
This clause of Part 1 is applicable except as follows.
5.2 Addition:
NOTE 101 An additional sample may be required for the test of 19.104. Six samples of the interlocks are required
for the test of 24.1.4.
5.3 Modification:
© IEC 2019
Instead of carrying out the tests in the order of clauses, the following sequence of clauses
and subclauses applies: 32, 22.113, 22.108, 22.116, 7 to 17, 20, 21 (except 21.101 to
21.105), 18, 19 (except 19.104), 22 (except 22.108, 22.113 and 22.116), 23 to 31, 21.101 to
21.105 and 19.104.
5.101 Microwave ovens are tested as motor-operated appliances.
5.102 Class III temperature-sensing probes are only subjected to the tests of 22.112.
6 Classification
This clause of Part 1 is applicable except as follows.
6.1 Modification:
Microwave ovens shall be class I.
7 Marking and instructions
This clause of Part 1 is applicable except as follows.
7.1 Addition:
Appliances shall be marked with the nominal frequency in megahertz of the ISM band in which
they operate.
If the removal of any cover results in microwave leakage exceeding the value specified in
Clause 32, the cover shall be marked with the substance of the following:
WARNING: Microwave energy – Do not remove this cover
If an appliance incorporates a socket-outlet protected by means of fuses other than D-type
fuses, it shall be marked with the rated current of the relevant fuse. When a miniature fuse-
link is provided, this marking shall indicate that the fuse-link is to have a high breaking
capacity.
If appliances have external enclosures, other than working surfaces, that cannot meet the
limit in Table 3 specified for external enclosures of motor-operated appliances, they shall be
marked with symbol IEC 60417-5041(2002-10) or with the substance of the following:
CAUTION: Hot surface.
7.6 Addition:
[symbol IEC 60417-5021 (2002-10)] equipotentiality

[symbol IEC 60417-5041 (2002-10)] caution, hot surface

– 14 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
7.12 Addition:
The instructions shall include the substance of the following:
– WARNING: If the door or door seals are damaged, the oven must not be operated until it
has been repaired by a competent person;
– WARNING: It is hazardous for anyone other than a competent person to carry out any
service or repair operation that involves the removal of any cover which gives protection
against exposure to microwave energy;
– WARNING: Liquids or other foods must not be heated in sealed containers since they are
liable to explode;
– WARNING: Microwave heating of beverages can result in delayed eruptive boiling,
therefore care must be taken when handling the container;
– WARNING: The contents of feeding bottles and baby food jars must be stirred or shaken
and the temperature checked before consumption, in order to avoid burns;
– the minimum height of free space necessary above the top surface of the oven;
– only use utensils that are suitable for use in microwave ovens;
– when heating food in plastic or paper containers, keep an eye on the oven due to the
possibility of ignition;
– if smoke is observed, switch off or unplug the appliance and keep the door closed in order
to stifle any flames;
– eggs in their shell and whole hard-boiled eggs should not be heated in microwave ovens
since they may explode even after microwave heating has ended;
– details for cleaning door seals, cavities and adjacent parts;
– the oven should be cleaned regularly and any food deposits removed;
– failure to maintain the oven in a clean condition could lead to deterioration of the surface
that could adversely affect the life of the appliance and possibly result in a hazardous
situation;
– only use the temperature probe recommended for this oven (for appliances having a
facility to use a temperature-sensing probe);
– the appliance should not be cleaned with a water jet (for appliances intended to stand on
the floor and which are not at least IPX5);
– statement on usage on commercial road vehicles (for appliances intended to be used on
commercial road vehicles);
– the appliance must not be cleaned with a steam cleaner (for appliances which are not at
least IPX5).
NOTE 101 If the oven is incorporated in a vending machine, these warnings and instructions may not be relevant
and therefore not required.
7.14 Addition:
The warning specified in 7.1 shall be in lettering at least 3 mm high.
The warning specified in 7.101 shall be in lettering at least 5 mm high.
The height of the triangle used with symbol IEC 60417-5041 (2002-10) shall be at least
12 mm.
7.15 Addition:
© IEC 2019
The marking specified for hot surfaces shall be visible when the appliance is operated as in
normal use, including when actuating any switch, adjusting any control or opening a lid or
door. It shall not be placed on a hot functional surface.
7.101 A label shall be provided, together with instructions for fixing it in a conspicuous place
close to the appliance. The label shall state the substance of the following.
– WARNING: Liquids or other foods must not be heated in sealed containers since they are
liable to explode;
– WARNING: Microwave heating of beverages can result in delayed eruptive boiling,
therefore care must be taken when handling the container;
– WARNING: The contents of feeding bottles and baby food jars must be stirred or shaken
and the temperature checked before consumption, in order to avoid burns.
Compliance is checked by inspection.
8 Protection against access to live parts
This clause of Part 1 is applicable.
9 Starting of motor-operated appliances
This clause of Part 1 is not applicable.
10 Power input and current
This clause of Part 1 is applicable.
11 Heating
This clause of Part 1 is applicable except as follows.
11.2 Addition:
Appliances, other than built-in appliances, are positioned as specified for heating
appliances.
A ceiling is placed over the appliance at the minimum height stated in the instructions. The
ceiling has a depth of 300 mm from the back wall of the test corner and a length at least
150 mm in excess of the width of the appliance.
Appliances intended to be fixed to the floor, and appliances with a mass greater than 40 kg
and not provided with rollers, castors or similar means, are installed in accordance with the
installation instructions. If no instructions are supplied, these appliances are placed on the
floor as near as possible to the walls of the test corner.
11.7 Replacement:
Appliances are operated in cycles, each cycle consisting of a heating period of 4 min followed
by a rest period of 1 min until steady conditions are established. The last cycle does not
include a rest period of 1 min. Boiling water is added to the water load when half of the water
load has evaporated.
– 16 – IEC 60335-2-90:2015+AMD1:2019 CSV
© IEC 2019
11.8 Addition:
The temperature rises of external surfaces are only measured on the surfaces that are not
placed against the wall and the floor of the test corner.
There are no temperature limits for air-outlet grilles and for surfaces up to a distance of
25 mm from them. When the required values for external enclosures of motor-operated
appliances are not met, the maximum temperature rise shall not be higher than two times the
values indicated.
12 Void
13 Leakage current and electric strength at operating temperature
This clause of Part 1 is applicable.
14 Transient overvoltages
This clause of Part 1 is applicable.
15 Moisture resistance
This clause of Part 1 is applicable except as follows.
15.2 Addition:
A quantity of 0,5 l of water containing approximately 1 % NaCl the same spillage solution is
poured steadily over the shelf over a period of 1 min. If the shelf can collect spilled liquid, it
is filled with the saline solution and a further 0,5 l is then added over a period of 1 min.
15.101 Temperature-sensing probes shall be constructed so that their insulation is not
affected by water.
Compliance is checked by the following test.
The probe is completely immersed in water containing approximately 1 % NaCl and having a
temperature of 20 °C ± 5 °C. The water solution is heated to the boiling point in approximately
15 min. The probe is then re
...