IEC 60335-2-42:2000

INTERNATIONAL IEC
STANDARD
60335-2-42
Fourth edition
2000-03
Safety of household and
similar electrical appliances –
Part 2-42:
Particular requirements for commercial electric
forced convection ovens, steam cookers and
steam-convection ovens
Sécurité des appareils électrodomestiques et analogues –
Partie 2-42:
Règles particulières pour les fours électriques à convection
forcée, les cuiseurs à vapeur électriques et les fours combinés
vapeur-convection électriques à usage collectif

Reference number
Numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series.
Consolidated publications
Consolidated versions of some IEC publications including amendments are

available. For example, edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the
base publication, the base publication incorporating amendment 1 and the base

publication incorporating amendments 1 and 2.

Validity of this publication
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology.
Information relating to the date of the reconfirmation of the publication is available
in the IEC catalogue.
Information on the subjects under consideration and work in progress undertaken
by the technical committee which has prepared this publication, as well as the list
of publications issued, is to be found at the following IEC sources:
• IEC web site*
•
Catalogue of IEC publications
Published yearly with regular updates
(On-line catalogue)*
• IEC Bulletin
Available both at the IEC web site* and as a printed periodical
Terminology, graphical and letter symbols
For general terminology, readers are referred to IEC 60050: International
Electrotechnical Vocabulary (IEV).
For graphical symbols, and letter symbols and signs approved by the IEC for
general use, readers are referred to publications IEC 60027: Letter symbols to be
used in electrical technology, IEC 60417: Graphical symbols for use on equipment.
Index, survey and compilation of the single sheets and IEC 60617: Graphical symbols
for diagrams.
* See web site address on title page.

INTERNATIONAL IEC
STANDARD
60335-2-42
Fourth edition
2000-03
Safety of household and
similar electrical appliances –
Part 2-42:
Particular requirements for commercial electric
forced convection ovens, steam cookers and
steam-convection ovens
Sécurité des appareils électrodomestiques et analogues –
Partie 2-42:
Règles particulières pour les fours électriques à convection
forcée, les cuiseurs à vapeur électriques et les fours combinés
vapeur-convection électriques à usage collectif

 IEC 2000  Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http://www.iec.ch
Commission Electrotechnique Internationale
PRICE CODE
T
International Electrotechnical Commission
For price, see current catalogue

– 2 – 60335-2-42  IEC:2000(E)

CONTENTS
Page
FOREWORD . 3

Clause
1 Scope . 5

2 Definitions. 5

3 General requirement . 8

4 General conditions for the tests . 8
5 Void . 8
6 Classification . 8
7 Marking and instructions . 9
8 Protection against access to live parts . 10
9 Starting of motor-operated appliances. 10
10 Power input and current . 11
11 Heating . 11
12 Void . 12
13 Leakage current and electric strength at operating temperature . 12
14 Void . 12
15 Moisture resistance. 12
16 Leakage current and electric strength . 14
17 Overload protection of transformers and associated circuits. 14
18 Endurance .14
19 Abnormal operation. 14
20 Stability and mechanical hazards . 16
21 Mechanical strength. 17
22 Construction .18
23 Internal wiring . 20
24 Components . 21
25 Supply connection and external flexible cords. 21

26 Terminals for external conductors . 21
27 Provision for earthing. 21
28 Screws and connections . 22
29 Creepage distance, clearances and distances through insulation . 22
30 Resistance to heat, fire and tracking . 22
31 Resistance to rusting . 22
32 Radiation, toxicity and similar hazards . 22
Annexes . 24
Figure 101 – Splash apparatus. 23

60335-2-42  IEC:2000(E) – 3 –

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
SAFETY OF HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –

Part 2-42: Particular requirements for commercial electric forced

convection ovens, steam cookers and steam-convection ovens

FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60335-2-42 has been prepared by subcommittee 61E: Safety of
electrical commercial catering equipment, of IEC technical committee 61: Safety of household
and similar electrical appliances.
It forms the fourth edition of IEC 60335-2-42 and replaces the third edition, published in 1994,
amendment 1 (1996) and amendment 2 (1998). It also replaces IEC 60335-2-46, published in
1986 and its amendment 1 (1990).

The text of this standard is based on the third edition, amendments 1 and 2, and the following
documents:
FDIS Report on voting
61E/354/FDIS 61E/367/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.

– 4 – 60335-2-42  IEC:2000(E)

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 third edition (1991) of that standard.

This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as
to convert it into the IEC standard: Safety requirements for commercial electric forced

convection ovens, steam cookers and steam-convection ovens

Where a particular subclause of part 1 is not mentioned in this part 2, that subclause applies

as far as is reasonable. Where this standard states "addition", "modification" or

"replacement", the relevant text in part 1 is to be adapted accordingly.

NOTE 1 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type;
Words in bold in the text are defined in clause 2.
NOTE 2 Subclauses, figures and notes which are additional to those in part 1 are numbered starting from 101.
A bilingual version of this standard may be issued at a later date.

60335-2-42  IEC:2000(E) – 5 –

SAFETY OF HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –

Part 2-42: Particular requirements for commercial electric forced

convection ovens, steam cookers and steam-convection ovens

1 Scope
This clause of part 1 is replaced by:
This standard deals with the safety of electrically operated commercial forced convection
ovens, steam cookers, steam-convection ovens and, exclusive of any other use, steam
generators, not intended for household 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.
NOTE 1 These appliances are used for example in kitchens such as in restaurants, canteens, hospitals and
commercial enterprises such as bakeries, butcheries, etc.
The electrical part of appliances making use of other forms of energy is also within the scope
of this standard.
So far as is practicable, this standard deals with the common hazards presented by these
types of appliances.
NOTE 2 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 additional requirements are specified by the national health authorities, the national
authorities responsible for the protection of labour, the national water supply authorities and similar authorities;
– in many countries additional requirements are specified for pressure appliances.
This standard does not apply to
– appliances where the cooking process is not only carried out by direct steam contact but
also with the food partially or completely immersed in a liquid;
– appliances designed exclusively for industrial purposes;
– 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);

– continuous process appliances for the mass production of food;
– microwave ovens;
– appliances with electrode heaters.
2 Definitions
This clause of part 1 is applicable except as follows.

– 6 – 60335-2-42  IEC:2000(E)

2.2.4 Addition:
NOTE The rated power input is the sum of the power inputs of all the individual elements in the appliance which

can be on at one time; where there are several such combinations possible that giving the highest power input is
used in determining the rated power input.

2.2.9 Replacement:
normal operation: Operation of the appliance under the following conditions:

Dry heat mode
The appliance is operated with all the shelves or the shelf trolley in position according to the
manufacturer's instructions but with no load. The controls are set so that the mean value
of the temperature over the thermostat cycle at the geometric centre of each usable space in
the interior of the oven is maintained at 220 °C ± 4 °C. Stepped controls are set so that this
temperature is 220 °C ± 15 °C.
For ovens which are unable to attain a temperature of 220 °C, the controls are set at the
maximum.
For ovens which are capable of attaining temperatures in excess of 270 °C, the controls are
set so that the mean value of the temperature is 50 °C ± 4 °C below the maximum tem-
perature attainable.
Steaming only mode
The appliance is operated in accordance with the manufacturer's instructions with all controls
intended to be operated by the user adjusted to their maximum setting until reaching
operating temperature. They are then readjusted, if possible, to the lowest setting that
maintains that temperature.
Appliances with steam generators intended to be filled by hand or by a manually operated
tap are filled to the indicated level on the steam generator.
Appliances with steam generators intended to be filled automatically are connected to a
water supply having the pressure designated by the manufacturer. Where the manufacturer
specifies a range of pressures, the pressure is adjusted to give the most unfavourable
conditions.
The incoming water is maintained at

– 15 °C ± 5 °C in the case of appliances intended for connection to a cold water supply;
– 60 °C ± 5 °C or the temperature indicated in the instruction sheet, whichever is the higher,
in the case of appliances intended for connection to a hot water supply only.
NOTE 1 If the appliance is intended for connection to either a hot or cold water supply, the temperature of the
water is that which gives the most unfavourable results.
Lids, doors, and covers are in position and closed.
The cooking compartment of the appliance contains a water load, initially at 15 °C ± 5 °C,
comprising 0,5 l/kg of the manufacturer's declared maximum food load. The water load is
evenly distributed between the shelves or pans.
NOTE 2 Since pans may be perforated to allow for circulation of steam, the water load may be contained in
suitable containers evenly distributed over the shelves or pans.

60335-2-42  IEC:2000(E) – 7 –

Combination mode
The appliance is operated as for the steaming only mode but with the forced convection fan/s

and elements for heating the cooking compartment on and the temperature controls set as

for the dry heat mode.
In all the above cases, motors incorporated in the appliance are operated in the intended

manner under the most severe conditions which can be expected in normal use taking into

account the manufacturer's instructions.

2.2.101
forced convection oven
an appliance intended for the cooking of food by heated air which is circulated by mechanical
means within the cooking compartment. The pressure within the cooking compartment
does not differ significantly from atmospheric pressure
2.2.102
steam cooker
an appliance intended for the cooking of food only by means of direct steam contact. The
pressure within the cooking compartment can exceed atmospheric pressure
2.2.103
atmospheric steam cooker
an appliance in which the pressure within the cooking compartment does not differ
significantly from atmospheric pressure
2.2.104
steam-convection oven
an appliance intended for the cooking of food either by means of direct steam contact or by
heated air circulated by mechanical means within the cooking compartment or by a
combination of these two modes. The pressure within the cooking compartment does not
differ significantly from atmospheric pressure
2.2.105
rated pressure
the maximum working pressure of steam cookers and steam generators assigned by the
manufacturer to the pressurized parts of the appliance
2.2.106
steam generator
that part of the appliance designed specifically for the generation of steam for exclusive use in

a cooking compartment
NOTE The steam generator may be combined within the cooking compartment, remote from the cooking
compartment but contained within the same casing, or as a separate unit providing steam for one or more
cooking compartments.
2.2.107
cooking compartment
that part of the appliance in which the cooking or food heating process takes place
2.2.108
indicated level
a mark on the appliance or steam generator to indicate the maximum liquid level for correct
operation
– 8 – 60335-2-42  IEC:2000(E)

2.2.109
installation wall
a special fixed construction containing supply facilities for appliances installed in conjunction

with it
3 General requirement
This clause of part 1 is applicable except as follows.

Addition:
NOTE 101 The d.c. component in the appliance neutral is limited (Australia).
4 General conditions for the tests
This clause of part 1 is applicable except as follows.
4.10 Addition:
Appliances intended for installation in a bank of other appliances and appliances intended to
be fixed to an installation wall are enclosed to obtain protection against electric shock and
harmful ingress of water equivalent to that obtained when installed in accordance with the
instructions provided with the appliance.
NOTE Appropriate enclosures or additional appliances may be needed for test purposes.
4.101 Appliances are tested as heating appliances, even if they incorporate a motor.
4.102 Appliances, when assembled in combination with or incorporating other appliances,
are tested in accordance with the requirements of this standard. The other appliances are
operated simultaneously in accordance with the requirements of the relevant standards.
If a part of the appliance or the whole appliance is intended to be used for different functions
covered by different standards, the relevant standard is applied to each function separately,
so far as is reasonable.
5 Void
6 Classification
This clause of part 1 is applicable except as follows.
6.1 Replacement:
Appliances shall be of class I with respect to protection against electric shock.
Compliance is checked by inspection and by the relevant tests.
NOTE Class 0I appliances are allowed (Japan).

60335-2-42  IEC:2000(E) – 9 –

6.2 Addition:
NOTE 101 For appliances intended to be installed in a kitchen, an appropriate degree of protection against

harmful ingress of water is required according to their height of installation (France).

7 Marking and instructions
This clause of part 1 is applicable except as follows.

7.1 Addition:
In addition, appliances shall be marked with
– the water pressure or range of pressures, in kilopascals (kPa), for appliances or steam
generators intended to be connected to a water supply, unless this is indicated in the
instruction sheet;
–the rated pressure, in kilopascals (kPa), on pressurized parts of the appliance.
7.6 Addition:
Add the following symbol:
*
equipotentiality (IEC 60417-5021-a)

7.12 Addition:
The instruction sheet of steam cookers and steam-convection ovens shall also include
information with regard to the maximum food load in kilograms.
The instruction sheet of steam cookers shall include the substance of the following warning:
WARNING – Do not open drain cocks or other emptying devices until the pressure has been
reduced to approximately atmospheric pressure.
7.12.1 Replacement:
The appliance shall be accompanied by an instruction sheet detailing any special precautions
necessary for installation. For appliances intended for installation in a bank of other
appliances and appliances intended to be fixed to an installation wall, details of how to
ensure appropriate protection against electric shock and harmful ingress of water shall be
supplied. If the controls of more than one appliance are combined in a separate enclosure,
detailed installation instructions shall be supplied. Instructions for user maintenance, for
example cleaning, shall also be given.
For appliances which are permanently connected to fixed wiring and for which leakage
currents may exceed 10 mA, particularly if disconnected or not used for long periods, or
during initial installation, the instruction sheet shall give recommendations regarding the
rating of protective devices i.e. earth leakage relays to be installed.
________
*
See IEC 60417-1:1998, Graphical symbols for use on equipment – Part 1: Overview and application, and
IEC 60417-2:1998, Graphical symbols for use on equipment – Part 2: Symbol originals.

– 10 – 60335-2-42  IEC:2000(E)

If the appliance is constructed so that it is not protected against water jets, clear and detailed
instructions for the user shall be delivered together with the appliance. It shall be stated in the

instructions that this appliance shall not be cleaned with a water jet.

Compliance is checked by inspection.

7.12.4 Addition:
The instructions for built-in appliances having a separate control panel for several
appliances shall state that the control panel is only to be connected to the specified
appliances in order to avoid a possible hazard.

7.15 Addition:
When it is not practical to place the marking of fixed appliances so that it is visible after
the appliance has been installed, the relevant information shall also be included in the
instructions for use or on an additional label which can be fixed near the appliance after
installation.
NOTE An example of such a fixed appliance is a built-in appliance.
7.101 Appliances and steam generators intended to be filled by hand or by a manually
operated tap shall be marked with an indicated level.
Compliance is checked by inspection.
7.102 Equipotential bonding terminals shall be indicated by the equipotentiality symbol
(see 7.6).
These indications shall not be placed on screws, removable washers or other parts which can
be removed when conductors are being connected.
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

9.1 Fan motors providing a cooling effect in order to comply with the requirements of
clause 11 shall start under all voltage conditions which may occur in use.
Compliance is checked by starting the motor three times at a voltage equal to 0,85 times
rated voltage, the motor being at room temperature at the beginning of the test.
The motor is started each time under the conditions occurring at the beginning of normal
operation or, for automatic appliances, at the beginning of the normal cycle of operation, the
motor being allowed to come to rest between successive starts. For appliances provided with
motors having other than centrifugal starting switches, this test is repeated at a voltage equal
to 1,06 times rated voltage.
60335-2-42  IEC:2000(E) – 11 –

In all cases, the motor shall start and it shall function in such a way that safety is not affected
and overload protection devices of the motor shall not operate.

NOTE 1 The supply source must be such that during the test the drop in voltage does not exceed 1 %.

NOTE 2 A fan motor for the convection fan only is not considered to provide a cooling effect.

10 Power input and current
This clause of part 1 is applicable except as follows.

10.1 Addition:
NOTE 101 For appliances having more than one heating unit, the total power input may be determined by
measuring the power input of each heating unit separately (see also 2.2.4).
11 Heating
This clause of part 1 is applicable except as follows.
11.2 Addition:
– 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
manufacturer's instructions. If no instructions are given, these appliances are considered
as appliances normally placed on the floor.
– Separate cooking compartments and steam generators are assembled in accordance
with the manufacturer's instructions and located in the test corner in such a manner that
they will have the most unfavourable effect on each other and on their surroundings.
11.4 Replacement:
Appliances are operated under normal operation such that the total power input of the
appliance is 1,15 times rated power input. If it is not possible to switch on all heating elements at
the same time, the test is made with each of the combinations that the switch arrangement will
allow, the highest load possible with each switching arrangement being in circuit.
If the appliance is provided with a control which limits the total power input, the test is made
with whichever combination of heating units, as may be selected by the control, imposes the
most severe condition.
If the temperature rise limits of motors, transformers or electronic circuits are exceeded, the
test is repeated with the appliance supplied at 1,06 times rated voltage. In this case only
the temperature rises of motors, transformers or electronic circuits are measured.
11.7 Replacement
The appliance is operated as follows:
Appliances with steam generators incorporated in the cooking compartment are operated
on continuous cycles until steady conditions are established. Each cycle comprises an
operating period followed by a rest period strictly sufficient, but in no case longer than 5 min,
to allow for replacing the water load, the water level in the steam generators intended to be
filled by hand being, if necessary, restored to the indicated level, in accordance with the
manufacturer's instructions.
– 12 – 60335-2-42  IEC:2000(E)

The operating period is equal to the maximum cooking time declared by the manufacturer or,
if such declaration is not provided, to the time taken for the appliance to reach the maximum

temperature conditions.
Appliances with separate steam generators are switch
...