SIST EN 60947-5-9:2008

SLOVENSKI STANDARD
01-februar-2008
Nizkonapetostne stikalne in krmilne naprave - 5-9. del: Krmilne naprave in stikalni
elementi - Stikala za hitrost pretoka (IEC 60947-5-9:2006)
Low-voltage switchgear and controlgear - Part 5-9: Control circuit devices and switching
elements - Flow rate switches (IEC 60947-5-9:2006)
Niederspannungsschaltgeräte - Teil 5-9: Steuergeräte und Schaltelemente -
Durchflussmengenschalter (IEC 60947-5-9:2006)
Appareillage à basse tension - Partie 5-9: Appareils et éléments de commutation pour
circuit de commande - Détecteurs de débit (IEC 60947-5-9:2006)
Ta slovenski standard je istoveten z: EN 60947-5-9:2007
ICS:
29.130.20 Nizkonapetostne stikalne in Low voltage switchgear and
krmilne naprave controlgear
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 60947-5-9
NORME EUROPÉENNE
November 2007
EUROPÄISCHE NORM
ICS 29.130.20
English version
Low-voltage switchgear and controlgear -
Part 5-9: Control circuit devices and switching elements -
Flow rate switches
(IEC 60947-5-9:2006)
Appareillage à basse tension -  Niederspannungsschaltgeräte -
Partie 5-9: Appareils et éléments Teil 5-9: Steuergeräte und
de commutation pour circuit Schaltelemente -
de commande - Durchflussmengenschalter
Détecteurs de débit (IEC 60947-5-9:2006)
(CEI 60947-5-9:2006)
This European Standard was approved by CENELEC on 2007-09-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60947-5-9:2007 E
Foreword
The text of document 17B/1500/FDIS, future edition 1 of IEC 60947-5-9, prepared by SC 17B,
Low-voltage switchgear and controlgear, of IEC TC 17, Switchgear and controlgear, was submitted to the
IEC-CENELEC parallel vote and was approved by CENELEC as EN 60947-5-9 on 2007-09-01.
This standard is to be used in conjunction with EN 60947-1:2004 and EN 60947-5-2:1998.
The provisions of the general rules, EN 60947-1, are applicable to this part of EN 60947, where
specifically called for. General rules clauses and subclauses thus applicable, as well as tables, figures
and annexes are identified by a reference to IEC 60947-1, for example 1.2.3 or Annex A of IEC 60947-1.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2008-06-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2010-09-01
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and covers essential requirements of
EC Directive EMC (2004/108/EC). See Annex ZZ.
Annexes ZA and ZZ have been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60947-5-9:2007 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 60947-5-9:2007
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

1)
IEC 60446 1999 Basic and safety principles for man-machine EN 60446 1999
interface, marking and identification -
Identification of conductors by colours or
numerals
2)
IEC 60947-1 2004 Low-voltage switchgear and controlgear - EN 60947-1 2004
Part 1: General rules + corr. November 2004

IEC 60947-5-2 1997 Low-voltage switchgear and controlgear - EN 60947-5-2 1998
(mod) Part 5-2: Control circuit devices and switching
A1 1999 elements - Proximity switches A1 1999
A2 2003 A2 2004
IEC 61000-3-2 2005 Electromagnetic compatibility (EMC) - EN 61000-3-2 2006
Part 3-2: Limits - Limits for harmonic current
emissions (equipment input current ≤16 A per
phase)
IEC 61000-3-3 1994 Electromagnetic compatibility (EMC) - EN 61000-3-3 1995
Part 3-3: Limits - Limitation of voltage + corr. July 1997
A1 2001 changes, voltage fluctuations and flicker in A1 2001
A2 2005 public low-voltage supply systems, for A2 2005
equipment with rated current ≤16 A per phase
and not subject to conditional connection

IEC 61000-4-2 1995 Electromagnetic compatibility (EMC) - EN 61000-4-2 1995
A1 1998 Part 4-2: Testing and measurement A1 1998
A2 2000 techniques - Electrostatic discharge immunity A2 2001
test
IEC 61000-4-3 2006 Electromagnetic compatibility (EMC) - EN 61000-4-3 2006
Part 4-3: Testing and measurement
techniques - Radiated, radio-frequency,
electromagnetic field immunity test

IEC 61000-4-4 2004 Electromagnetic compatibility (EMC) - EN 61000-4-4 2004
Part 4-4: Testing and measurement
techniques - Electrical fast transient/burst
immunity test
1)
EN 60446:1999 is superseded by EN 60446:2007, which is based on IEC 60446:2007.
2)
EN 60947-1:2004 is superseded by EN 60947-1:2007, which is based on IEC 60947-1:2007.

Publication Year Title EN/HD Year
IEC 61000-4-6 2003 Electromagnetic compatibility (EMC) -
+ A1 2004 Part 4-6: Testing and measurement
+ A2 2006 techniques - Immunity to conducted EN 61000-4-6 2007
disturbances, induced by radio-frequency + corr. August 2007
fields
IEC 61000-4-8 1993 Electromagnetic compatibility (EMC) - EN 61000-4-8 1993
A1 2000 Part 4-8: Testing and measurement A1 2001
techniques - Power frequency magnetic field
immunity test
IEC 61000-4-11 2004 Electromagnetic compatibility (EMC) - EN 61000-4-11 2004
Part 4-11: Testing and measurement
techniques - Voltage dips, short interruptions
and voltage variations immunity tests

IEC 61000-4-13 2002 Electromagnetic compatibility (EMC) - EN 61000-4-13 2002
Part 4-13: Testing and measurement
techniques - Harmonics and interharmonics
including mains signalling at a.c. power port,
low frequency immunity tests
IEC 61140 2001 Protection against electric shock - Common EN 61140 2002
A1 (mod) 2004 aspects for installation and equipment A1 2006

IEC 61558-2-6 1997 Safety of power transformers, power supply EN 61558-2-6 1997
units and similar -
Part 2-6: Particular requirements for safety
isolating transformers for general use

CISPR 11 (mod) 2003 Industrial, scientific and medical (ISM)
+ A1 2004 radio-frequency equipment - Electromagnetic EN 55011 2007
disturbance characteristics - Limits and
methods of measurement
- 5 - EN 60947-5-9:2007
Annex ZZ
(informative)
Coverage of Essential Requirements of EC Directives

This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and within its scope the standard covers all
relevant essential requirements as given in Article 1 of Annex I of the EC Directive 2004/108/EC.

Compliance with this standard provides one means of conformity with the specified essential
requirements of the Directive concerned.

WARNING: Other requirements and other EC Directives may be applicable to the products falling within
the scope of this standard.
NORME CEI
INTERNATIONALE
IEC
60947-5-9
INTERNATIONAL
Première édition
STANDARD
First edition
2006-12
Appareillage à basse tension –
Partie 5-9:
Appareils et éléments de commutation
pour circuit de commande –
Détecteurs de débit
Low-voltage switchgear and controlgear –
Part 5-9:
Control circuit devices and switching elements –
Flow rate switches
© IEC 2006 Droits de reproduction réservés ⎯ Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
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Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
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Pour prix, voir catalogue en vigueur
For price, see current catalogue

60947-5-9 © IEC:2006 – 3 –
CONTENTS
FOREWORD.7

1 General.11
1.1 Scope and object.11
1.2 Normative references.11
2 Terms and definitions .13
2.1 Basic definitions .15
2.2 Characteristics of a flow rate switch .17
2.3 Delay times.19
3 Classification.19
3.1 General.19
3.2 Classification according to sensing means .21
3.3 Classification according to the construction form .21
3.4 Classification according to the switching element function.21
3.5 Classification according to the type of output.21
3.6 Classification according to the method of connection.21
4 Characteristics.21
4.1 Summary of characteristics.21
4.2 Operating conditions .21
4.3 Rated and limiting values for the flow rate switch .23
4.4 Utilization categories for the switching element .27
5 Product information .27
5.1 Nature of information.27
5.2 Marking.27
5.3 Instruction for installation, operation and maintenance .29
6 Normal service, mounting and transport conditions.29
6.1 Normal service conditions .29
6.2 Conditions during transport and storage .31
6.3 Mounting.31
6.4 Indicating means.31
7 Constructional and performance requirements.31
7.1 Constructional requirements.31
7.2 Performance requirements .35
7.3 Shock and vibration.47
8 Tests.47
8.1 Kinds of tests.49
8.2 Compliance with constructional requirements .49
8.3 Performance.49
8.4 Verification of set point and delay times .63
8.5 Verification of the electromagnetic compatibility .65
8.6 Test results and test report.69

60947-5-9 © IEC:2006 – 5 –
Figure 1 – Relationship between operating points of a flow rate switch .23
Figure 2 – Relationship between U and U .23
e B
Figure 3 – Test circuit for the verification of time delay before availability .55
Figure 4 – Signal output across load in Figure 3 .55
Figure 5 – Test circuit for the verification of minimum operational current OFF-state
current, voltage drop and independent snap action .57
Figure 6 – Short-circuit testing .63
Figure 7 – Testing set point and delay times .65

Table 1 – Classification of flow rate switches .19
Table 2 – Acceptance criteria.43
Table 3 – Immunity tests.45

60947-5-9 © IEC:2006 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 5-9: Control circuit devices and switching elements –
Flow rate switches
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,
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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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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.
International Standard IEC 60947-5-9 has been prepared by subcommittee 17B: Low-voltage
switchgear and controlgear, of IEC technical committee 17: Switchgear and controlgear.
The text of this standard is based on the following documents:
FDIS Report on voting
17B/1500/FDIS 17B/1525/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.

60947-5-9 © IEC:2006 – 9 –
This International Standard should be used in conjunction with IEC 60947-1 and
IEC 60947-5-2.
The provisions of the general rules, IEC 60947-1, are applicable to this standard, where
specifically called for. General rules clauses and subclauses thus applicable, as well as
tables, figures and annexes are identified by a reference to IEC 60947-1, for example 1.2.3 or
Annex A of IEC 60947-1.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60947 series, under the general title Low-voltage switchgear and
controlgear, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.
60947-5-9 © IEC:2006 – 11 –
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 5-9: Control circuit devices and switching elements –
Flow rate switches
1 General
1.1 Scope and object
This part of IEC 60947 applies to flow rate switches that sense the rate of flow of a gas, a
liquid or a granular solid. These switches change their output state if a pre-set value for the
speed of flow is exceeded.
These flow rate switches are self-contained, have semiconductor switching element(s) and
are intended to be connected to circuits, the rated voltage of which does not exceed 250 V
50 Hz/60 Hz a.c. or 300 V d.c.
This standard does not specify the additional measures that are necessary for flow rate
switches used in conjunction with explosive sensing materials and/or in an explosive location.
This standard is not intended to cover devices with analogue outputs.
The object of this standard is to state for flow rate switches:
– definitions;
– classifications;
– characteristics;
– product information;
– normal service, mounting and transport conditions;
– constructional and performance requirements;
– tests to verify rated characteristics.
1.2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60446:1999, Basic and safety principles for man-machine interface, marking and
identification – Identification of conductors by colours or numerals
IEC 60947-1:2004, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-5-2:1997, Low-voltage switchgear and controlgear – Part 5-2: Control circuit
devices and switching elements – Proximity switches
Amendment 1 (1999)
Amendment 2 (2003)
60947-5-9 © IEC:2006 – 13 –
IEC 61000-3-2:2005, Electromagnetic compatibility (EMC) – Part 3-2: Limits – Limits for
harmonic current emissions (equipment input current ≤ 16 A per phase)
IEC 61000-3-3:1994, Electromagnetic compatibility (EMC) – Part 3-3: Limits – Limitation of
voltage changes, voltage fluctuations and flicker in public low-voltage supply systems for
equipment with rated current ≤ 16 A per phase and not subject to conditional connection

Amendment 1 (2001)
Amendment 2 (2005)
IEC 61000-4-2:1995, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
Amendment 1 (1998)
Amendment 2 (2000)
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and
measurement techniques – Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-4:2004, Electromagnetic compatibility (EMC) – Part 4-4: Testing and
measurement techniques – Electrical fast transient/burst immunity test
IEC 61000-4-6:2003, Electromagnetic compatibility (EMC) – Part 4-6: Testing and
measurement techniques – Immunity to conducted disturbances, induced by radio-frequency
fields
Amendment 1 (2004)
Amendment 2 (2006)
IEC 61000-4-8:1993, Electromagnetic compatibility (EMC) – Part 4-8: Testing and
measurement techniques – Power frequency magnetic field immunity test
Amendment 1 (2000)
IEC 61000-4-11:2004, Electromagnetic compatibility (EMC) – Part 4-11: Testing and
measurement techniques – Voltage dips, short interruptions and voltage variations immunity
tests
IEC 61000-4-13:2002, Electromagnetic compatibility (EMC) – Part 4-13: Testing and
measurement techniques – Harmonics and interharmonics including mains signalling at a.c.
power port, low-frequency immunity tests
IEC 61140:2001, Protection against electric shock – Common aspects for installation and
equipment
Amendment 1 (2004)
IEC 61558-2-6, Safety of power transformers, power supply units and similar – Part 2:
Particular requirements for safety isolating transformers for general use
CISPR 11:2003, Industrial, scientific and medical (ISM) radio-frequency equipment –
Electromagnetic disturbance characteristics – Limits and methods of measurement
Amendment 1 (2004)
2 Terms and definitions
For the purposes of this document, the relevant definitions given in Clause 2 of IEC 60947-1
and Clause 2 of IEC 60947-5-2 apply with the following additional definitions.

60947-5-9 © IEC:2006 – 15 –
Alphabetical index of definitions
Reference
A
Active zone. 2.2.1
Adjuster (for a flow rate switch). 2.2.4

F
Flow direction . 2.1.6
Flow rate sensor . 2.1.2
Flow rate switch. 2.1.1

H
Homogenization zone. 2.1.7
Hysteresis (H). 2.2.8

M
Maximum temperature gradient. 2.2.9
Medium. 2.1.4

R
Reference medium. 2.1.5
Repeat accuracy (R). 2.2.7

S
Semiconductor switching element . 2.1.3
Sensing range . 2.2.6
Sensor tip . 2.2.2
Set point (s). 2.2.5
s
Submersion depth. 2.2.3

T
Time delay before availability (t). 2.3.3
v
Turn-off time . 2.3.2
Turn-on time . 2.3.1

2.1 Basic definitions
2.1.1
flow rate switch
device consisting of a flow rate sensor and a switching element which, in accordance with an
increasing or decreasing flow of a defined medium (flow medium), changes the output signal
at a predetermined value
60947-5-9 © IEC:2006 – 17 –
2.1.2
flow rate sensor
transducer which detects the rate of flow of a medium in an active area
2.1.3
semiconductor switching element
element designed to switch the current in an electric circuit by controlling conductivity of a
semiconductor
2.1.4
medium
gaseous, liquid, or fine granular solid, or a combination thereof
2.1.5
reference medium
medium with which measurements according to this standard are made
2.1.6
flow direction
direction from which the medium flows towards the sensor
2.1.7
homogenization zone
zone in front of and behind the sensor with undisturbed flow necessary to homogenize the
flow of the medium in order to obtain correct measurement results
2.2 Characteristics of a flow rate switch
2.2.1
active zone
zone in which a flow rate is detected
NOTE This can be, for example the surface of the sensor tip or inner surface of a sensor tube.
2.2.2
sensor tip
tip which is surrounded by the medium to sense the flow speed
2.2.3
submersion depth
minimum length of the sensor tip that needs to be surrounded by the medium to obtain correct
measurement results
2.2.4
adjuster (for a flow rate switch)
part of a flow rate switch used to set the operating parameters
NOTE This may be a potentiometer, a push-button and/or a data interface.
2.2.5
set point
s
s
rate of flow of the medium at which the switching element changes its state
2.2.6
sensing range
range between a minimum and a maximum rate of flow within which the set point can be
adjusted
60947-5-9 © IEC:2006 – 19 –
2.2.7
repeat accuracy
R
value of variation of the set point under specified conditions
2.2.8
hysteresis
H
difference between the set points at which the switching element turns on and turns off
2.2.9
maximum temperature gradient
maximum specified value of a temperature change of the medium at constant rate within a
specified time that does not lead to a change of state of the switching element
2.3 Delay times
2.3.1
turn-on time
time required for the semiconductor switching element to respond after the measured input
variable has exceeded the set point under specified conditions
2.3.2
turn-off time
time required for the semiconductor switching element to respond after the measured input
variable has fallen below the set point under specified conditions
2.3.3
time delay before availability
t
v
time between the switching on of the supply voltage and the instant at which the flow rate
switch becomes ready to operate correctly
3 Classification
3.1 General
Flow rate switches are classified according to various general characteristics as shown in
Table 1.
Table 1 – Classification of flow rate switches
st nd rd th th
1 position/ 2 position/ 3 position/ 4 position/ 5 position/
1 digit 1 digit 1 digit 1 digit 1 digit
Sensing Construction Switching element Type of Method of
means form function (output) output connection

3.2 3.3 3.4 3.5 3.6
F Flow 1 One sensor tip A NO (make) P PNP output, 3 or 1 Integral leads
4 terminal d.c.
2 Two sensor tips B NC (break) 2 Integral
N NPN output, 3 or connector
3 Flush with tube C Changeover
4 terminal d.c.
(make – break) 3 Screw terminal
A 3 or 4 terminal
P Programmable 9 Other
a.c.
by user
B Bus interface
S Other
S Other
60947-5-9 © IEC:2006 – 21 –
3.2 Classification according to sensing means
In this standard the sensing means is designated by a capital letter placed in the first position.
3.3 Classification according to the construction form
The construction form is designated by a one-digit number placed in the second position.
3.4 Classification according to the switching element function
The switching element function is designated by a capital letter placed in the third position.
3.5 Classification according to the type of output
The type of output is designated by a capital letter placed in the fourth position.
3.6 Classification according to the method of connection
The method of connection is designated by a one-digit number placed in the fifth position.
4 Characteristics
4.1 Summary of characteristics
4.1.1 General
The characteristics of flow rate switches shall be stated in the following terms:
– Operating conditions (4.2)
– Rated and limiting values (4.3)
Rated voltages (4.3.1)
Currents (4.3.2)
Rated supply frequency (4.3.3)
Normal load and abnormal load characteristics (4.3.4)
Short-circuit characteristics (4.3.5)
– Utilisation categories for the switching element (4.4)
4.1.2 Operation of a flow rate switch
The output state is determined by
– the rate of flow in the active zone of the flow sensor, and
– the set point(s).
4.2 Operating conditions
4.2.1 Operating points of a flow rate switch
The relationship between the operating points is shown in Figure 1.

60947-5-9 © IEC:2006 – 23 –
Sensing range
A B
S S
s min s max
S –H S +H
s min s max
IEC  2204/06
Key
A range below lower limit of sensing range
B range above upper limit of sensing range

Figure 1 – Relationship between operating points of a flow rate switch
4.2.2 Sensing range
Operating range values shall be stated by the manufacturer.
4.3 Rated and limiting values for the flow rate switch
4.3.1 Voltages
The flow rate switch is defined by the following rated voltages.
4.3.1.1 Rated operational voltage (U )
e
The rated operational voltage (U ) (or range) shall not exceed 250 V a.c. or 300 V d.c.
e
NOTE The manufacturer may state a range between the limiting values which includes all the tolerances of U ,
e
this range shall be designated U .
B
The relationship between U and U is shown in Figure 2.
e B
U U
e min e max
Rated operational voltage (U )
e
U
B
U –15 % U +10 %
e min e max
IEC  2205/06
Figure 2 – Relationship between U and U
e B
4.3.1.2 Rated insulation voltage (U )
i
The rated insulation voltage of a flow rate switch is the value of voltage to which the dielectric
voltage tests and creepage distances are referred.
For flow rate switches, the rated insulation voltage shall be equal to or greater than the
highest rated operational voltage.

60947-5-9 © IEC:2006 – 25 –
4.3.1.3 Rated impulse withstand voltage (U )
imp
Subclause 4.3.1.3 of IEC 60947-1 applies.
4.3.1.4 Voltage drop (U )
d
The voltage drop is the voltage measured across the active output of the flow rate switch
when carrying the rated operational current under specified conditions. The values are
specified in 7.2.1.13.
4.3.2 Currents
The switching element of a flow rate switch is defined by the following currents.
4.3.2.1 Rated operational current (I )
e
See 7.2.1.9.
4.3.2.2 Minimum operational current (I )
m
See 7.2.1.10.
4.3.2.3 OFF-state current (I )
r
See 7.2.1.11.
4.3.2.4 No-load supply current (I )
o
The maximum no-load supply current of a three- or four-terminal flow rate switch shall be
stated by the manufacturer.
4.3.3 Rated supply frequency
The rated supply frequency for a.c. flow rate switches shall be 50 Hz and/or 60 Hz.
4.3.4 Normal load and abnormal load characteristics
4.3.4.1 Rated making and breaking capacities and behaviour of switching element
under normal conditions
A semiconductor switching element shall comply with the requirements given in Table 4 of
IEC 60947-5-2.
NOTE For a semiconductor switching element to which a utilization category is assigned, it is not necessary to
specify separately a making and breaking capacity.
4.3.4.2 Making and breaking capacities under abnormal conditions
A semiconductor switching element shall comply with the requirements given in Table 5 of
IEC 60947-5-2.
NOTE For a semiconductor switching element to which a utilization category is assigned, it is not necessary to
specify separately a making and breaking capacity.
4.3.5 Short-circuit characteristics
The rated conditional short-circuit current of a flow rate switch is 100 A prospective. The flow
rate switch shall withstand satisfactorily the test specified in 8.3.4.

60947-5-9 © IEC:2006 – 27 –
4.4 Utilization categories for the switching element
The utilization categories as given in Table 2 of IEC 60947-5-2 are considered standard. Any
other type of application shall be based on agreement between manufacturer and user, but
information given in the manufacturer's documentation may constitute such an agreement.
5 Product information
5.1 Nature of information
The following information shall be given by the manufacturer.
Identification
a) The manufacturer's name or trade mark.
b) A type designation or other marking which makes it possible to identify the flow rate switch
and get the relevant documentation from the manufacturer.
c) Reference to this standard if the manufacturer claims compliance.
Basic rated values and utilization
d) Rated operational voltage(s) (see 4.3.1.1).
e) Utilization category and rated operational currents at the rated operational voltages and
rated frequency/frequencies or at direct current, d.c. or reference to relevant
specifications.
f) Rated insulation voltage (see 4.3.1.2).
g) Rated impulse withstand voltage (see 4.3.1.3).
h) IP code (see 7.1.10).
i) Pollution degree (see 6.1.4.2).
j) Type and maximum ratings of short-circuit protective device (see 7.2.5).
k) Rated conditional short-circuit current (see 4.3.5).
l) Sensing range (see 7.2.1.3).
m) Repeat accuracy (see 7.2.1.4).
n) Hysteresis (see 7.2.1.5).
o) Delay times (see 7.2.1.6)
p) Minimum operational current (see 7.2.1.10).
q) OFF-state current (see 7.2.1.11).
r) No-load supply current (see 4.3.2.4).
s) Voltage drop (see 7.2.1.13).
t) Switching element function (see 2.4.1 of IEC 60947-5-2).
u) Mounting arrangement.
v) Physical dimensions.
5.2 Marking
5.2.1 General
Data under a) and b) of 5.1 shall be marked on the body of the flow rate switch or on a
nameplate permanently attached to the product.

60947-5-9 © IEC:2006 – 29 –
NOTE This requirement is intended to permit the complete information to be obtained from the manufacturer.
Marking shall be indelible and easily legible, and shall not be placed on parts normally
removable in service. If the dimension of the housing of the flow rate switch is too small, the
marking may be placed on the cord or on a tag permanently attached to the cord, located no
further than 100 mm from the body of the device.
Data under c) to v) of 5.1, when not marked on the flow rate switch, shall be included in the
manufacturer's documentation.
5.2.2 Terminal identification and marking
Subclause 7.1.7.4 applies.
5.2.3 Functional markings
The active area and the intended flow direction (if applicable) shall be marked when either the
active area or the intended flow direction is not apparent by the construction of the flow rate
switch.
5.3 Instruction for installation, operation and maintenance
The manufacturer shall specify in his documentation the conditions for installation, operation
and maintenance of the flow rate switch.
The above documents shall indicate the recommended extent and frequency of maintenance,
if any.
6 Normal service, mounting and transport conditions
6.1 Normal service conditions
6.1.1 General
Flow rate switches complying with this standard shall be capable of operating under the
following standard conditions.
If the conditions for operation differ from those given in this standard, they shall be based on
agreement between manufacturer and user, but information given in the manufacturer's
documentation may constitute such an agreement.
6.1.2 Operating temperatures
6.1.2.1 Temperature of the medium
The rated temperature range of the medium shall be stated by the manufacturer.
6.1.2.2 Ambient air temperature
Flow rate switches shall operate between the ambient air temperatures of 0 °C and 60 °C.
The operating characteristics shall be maintained over the permissible range of ambient
temperature.
6.1.3 Altitude
Subclause 6.1.2 of IEC 60947-1 applies.

60947-5-9 © IEC:2006 – 31 –
6.1.4 Climatic conditions
6.1.4.1 Humidity
The relative humidity (RH) of the air shall not exceed 95 %.
6.1.4.2 Pollution degree
Unless otherwise stated by the manufacturer, a flow rate switch is intended for installation
under environmental conditions of pollution degree 3 as defined in 6.1.3.2 of IEC 60947-1.
However, other pollution degrees may apply, depending upon the micro-environment.
6.2 Conditions during transport and storage
A special agreement shall be made between the user and the manufacturer if the conditions
during transport and storage, e.g. temperature and humidity conditions, differ from those
defined in 6.1.
6.3 Mounting
Mounting dimensions and conditions shall be stated by the manufacturer.
6.4 Indicating means
Flow rate switches may have one or more coloured indicating means. If applicable they shall
have the following meaning:
a) green (constant) power ON;
b) yellow (constant) switching element ON;
c) red (constant) failure indication;
d) any other colour (constant) or one of the above mentioned colours (flashing): other
functions (e.g. short-circuit indication).
7 Constructional and performance requirements
7.1 Constructional requirements
7.1.1 Materials
Subclause 7.1.1 of IEC 60947-5-2 applies.
7.1.2 Current-carrying parts and their connections
Subclause 7.1.2 of IEC 60947-1 applies.
7.1.3 Clearances and creepage distances
Subclause 7.1.3 of IEC 60947-1 applies.
7.1.4 Actuation
Flow rate switches are tested for operation by adjusting the rate of flow of a medium specified
by the manufacturer across the set point for both increasing and decreasing flow rates.

60947-5-9 © IEC:2006 – 33 –
7.1.5 Vacant
7.1.6 Vacant
7.1.7 Terminals
7.1.7.1 Constructional requirements
Subclause 7.1.7.1 of IEC 60947-1 applies.
7.1.7.2 Connecting capacity
Subclause 7.1.7.2 of IEC 60947-1 applies.
7.1.7.3 Connection means
Subclause 7.1.7.3 of IEC 60947-1 applies with the following additions.
Flow rate switches may have integral connecting leads; in this case the outer sheath of the
+0,1
connecting leads shall be 2 m long.
7.1.7.4 Connection identification and marking
Subclause 7.1.7.4 of IEC 60947-1 applies with the following additions.
Flow rate switches with integral connecting leads shall have wires identified with colours
according to Table 3 of IEC 60947-5-2.
The bicolour combination green-and-yellow shall be used for identifying the protective
conductor and for no other purposes (see IEC 60446). The colour green and/or the colour
yellow shall not be used where there is a possibility of confusion with the protective
conductor.
7.1.8 Vacant
7.1.9 Provisions for protective earthing
7.1.9.1 Constructional requirements
Subclause 7.1.9.1 of IEC 60947-1 applies with the following addition.
NOTE Flow rate switches with maximum rated voltages not exceeding either 50 V a.c. or 120 V d.c. need no
provision for protective earthing.
Consideration should be given to the safety insulation of the supply and its transformer (if
any). Where the supply is from a transformer, it should comply with IEC 61558-2-6.
7.1.9.2 Protective earth terminal
Subclause 7.1.9.2 of IEC 60947-1 applies.
7.1.9.3 Protective earth terminal marking and identification
Subclause 7.1.9.3 of IEC 60947-1 applies.
7.1.10 Degree of p
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