IEC 60730-2-9:2015/AMD1:2018

IEC 60730-2-9 ®
Edition 4.0 2018-01
INTERNATIONAL
STANDARD
colour
inside
AMENDMENT 1
Automatic electrical controls –
Part 2-9: Particular requirements for temperature sensing controls

IEC 60730-2-9:2015-05/AMD1:2018-01(en)

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IEC 60730-2-9 ®
Edition 4.0 2018-01
INTERNATIONAL
STANDARD
colour
inside
AMENDMENT 1
Automatic electrical controls –

Part 2-9: Particular requirements for temperature sensing controls

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 97.120 ISBN 978-2-8322-5263-5

– 2 – IEC 60730-2-9:2015/AMD1:2018
© IEC 2018
FOREWORD
This amendment has been prepared by subcommittee IEC technical committee 72: Automatic
electrical controls.
The text of this amendment is based on the following documents:
FDIS Report on voting
72/1112A/FDIS 72/1118/RVD
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base 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• withdrawn,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.
A bilingual version of this publication may be issued at a later date.

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_____________
Table 1 – Required information and methods of providing information
Replace the existing Note 102 by the following:
In China, the use of liquid metal in or on cooking or food handling equipment is not allowed.
In Canada parts of controls containing mercury is not allowed.
Annex EE – Guide to the application of temperature sensing controls within the
scope of IEC 60730-2-9
EE.1.2 Overview
Replace the third paragraph by the following:

© IEC 2018
Controls classified as type 2 are also assessed to provide a degree of confidence in terms of
their operating temperature. Tests are made to determine that the spread of operating
temperature in the new condition is within the manufacturer’s declared value, and also to
determine that drift of operating temperature is within the manufacturer’s declared value after
the specified tests.
NOTE A temperature sensing control can be classified for more than one purpose, depending upon the
application.
EE.3.3 Types of temperature sensing controls according to their purpose
Replace the existing text of this subclause by the following:
EE.3.3.1 Thermostat
Cycling temperature sensing control, which is intended to keep a temperature between two
particular values under normal operating conditions of the controlled equipment and which
may have provision for setting by the user. A thermostat is therefore also classified as an
operating control with at least type 1 action (electromechanical) or at least Class A control
function (electronic control). A typical usage of thermostats is to control the normal running
temperature of a room heater or hot plate.
Thermostats are defined in IEC 60335-1 as follows:
thermostat
temperature-sensing device, the operating temperature of which may be either fixed or
adjustable and which during normal operation keeps the temperature of the controlled part
between certain limits by automatically opening and closing a circuit
EE.3.3.2 Temperature limiter
Temperature sensing control which is intended to keep a temperature below or above one
particular value during normal operating conditions of the controlled equipment and which
may have provision for setting by the user. A temperature limiter is therefore also classified
as an operating control with Class A control functions. Under certain applications, a
temperature limiter may be classified as an operating control with Class B control
functions. A typical usage of a temperature limiter with Class A function is to switch off a
kettle on boiling.
A temperature limiter may be of the automatic or of the manual reset type. It does not make
the reverse operation during the normal duty cycle of the appliance.
Temperature limiters are defined in IEC 60335-1 as follows:
temperature limiter
temperature-sensing device, the operating temperature of which may be either fixed or
adjustable and which during normal operation operates by opening or closing a circuit when
the temperature of the controlled part reaches a predetermined value
NOTE 1 A temperature limiter does not make the reverse operation during the normal duty cycle of the
appliance. It can require manual resetting.
NOTE 2 A temperature limiter control is used to limit the temperature of part of the appliance/equipment during
normal operation of the appliance. The differential between the operating and remake temperature of a
temperature limiter is large.
NOTE 3 An electromechanical temperature limiter can be either a type 1 or type 2 control depending on the
application.
NOTE 4 An electronic temperature limiter is classified as an operating control with Class A control functions.
Under certain applications, a temperature limiter may be classified as an operating control with Class B control
functions.
– 4 – IEC 60730-2-9:2015/AMD1:2018
© IEC 2018
EE.3.3.3 Thermal cut-out
Temperature sensing control intended to keep a temperature below or above one particular
value during abnormal operating conditions of the controlled equipment and which has no
provision for setting by the user. A thermal cut-out is therefore also classified as a
protective control with a type 2 action (electromechanical) or at least Class B control function
(electronic control). Under certain applications, an electronic thermal cut-out may be
classified as a protective control with Class C control functions, for example, water heaters.
Typical usage of thermal cut-outs is to provide overheating protection of a room heater, hot
plate or water heater.
A thermal cut-out may be of the automatic or manual reset type.
Thermal cut-outs are defined in IEC 60335-1 as follows:
a) thermal cut-out
device which during abnormal operation limits the temperature of the controlled part by
automatically opening the circuit, or by reducing the current, and is constructed so that its
setting cannot be altered by the user
NOTE 1 A thermal cut-out control does not operate during normal operation of the appliance. It is used to
regulate or limit the temperature of part of the appliance/equipment in fault conditions.
NOTE 2 When a thermal cut-out is built-in or on a motor, and is specifically intended to protect the motor against
overheating due to running overload and failure to start and carries the motor current and is sensitive to motor
temperature and current, it is a thermal motor protector. Thermal motor protectors are covered by
IEC 60730-2-22.
b) self-resetting thermal cut-out
thermal cut-out that automatically restores the current after the relevant part of the appliance
has cooled down sufficiently
NOTE 1 A self-resetting thermal cut-out control does not operate during normal operation of the appliance. It is
used to regulate the temperature of part of the appliance/equipment in fault conditions.
NOTE 2 A self-resetting thermal cut-out is normally a type 2 control depending on the application and a
declaration of number of cycles is between 300 and 10 000 (depending upon the end product application).
c) non-self-resetting thermal cut-out
thermal cut-out that requires a manual operation for resetting, or replacement of a part, in
order to restore the current
NOTE 1 Manual operation includes disconnection of the appliance from the supply mains.
NOTE 2 A non-self- resetting thermal cut-out control does not operate during normal operation of the
appliance. It is used to limit the temperature of part of the appliance/equipment in fault conditions and can
disconnect the appliance from the supply mains.
NOTE 3 A non-self- resetting thermal cut-out control is usually a type 2 control that provides either micro-
disconnection or full-disconnection. A declaration of the number of cycles of operation would be at least 30 cycles.
The following thermal cut-out is not specifically defined in IEC 60335 but can be used in
appliances:
voltage maintained thermal cut-out
thermal cut-out which is maintained in its operated condition by the voltage which appears
across it in that condition
NOTE 1 A voltage maintained thermal cut-out control can only be reset if the appliance is disconnected from
the electrical supply.
NOTE 2 A voltage maintained thermal cut-out control does not operate during normal operation of the
appliance. It is used to limit the temperature of part of the appliance/equipment in fault conditions and can
disconnect the appliance from the supply mains.
NOTE 3 A voltage maintained thermal cut-out control is a type 2 control. A declaration of the number of cycles
of operation would be at least 1 000 cycles.

© IEC 2018
EE.3.3.3.1 Motor protector
Automatic control that is specifically intended to protect the windings of an electric motor from
overheating.
EE.3.3.3.2 Thermal motor protector
Automatic control, built-in or on a motor, that is specifically intended to protect the motor
against overheating due to running overload and failure to start. The control carries the motor
current and is sensitive to motor temperature and current.
NOTE 1 These are covered by IEC 60730-2-22.
NOTE 2 If it is not built-in or on a motor, does not carry the motor current, is not sensitive to motor temperature
and current, it is a thermal cut-out, which is covered by IEC 60730-2-9.
EE.3.3.4 Single operation device (SOD)
EE.3.3.4.1 Bimetallic
Control having a bimetallic temperature sensing element, which is intended to operate only
once, and then requires complete replacement. A single operation device is therefore also
classified as a protective control with type 2 action (electromechanical). Typical usage of
single operation devices is to provide overheating protection of an electric kettle or water
heater.
A bimetallic single operation device does not reset above a declared temperature.
EE.3.3.4.2 Non-bimetallic
A non-bimetallic single operation device denotes a control having a non-bimetallic sensing
device, the operation of which cannot be separated from other functions of the control, and
which operates only once and then requires complete replacement. Such a device is
classified as a protective control.
If such parts can be tested separately, then they are identified as thermal links, which are not
within the scope of IEC 60730-2-9 and are covered by IEC 60691.
Typical usage of single operation devices is to provide overheating protection of an electric
kettle or water heater.
EE.3.3.5 Protective controls
These are defined in IEC 60335-1 as follows:
protective device
device, the operation of which prevents a hazardous situation under abnormal operation
conditions
NOTE 1 The aim of a protective device is to reduce the risk of a hazard by restoring the appliance to a fail-safe
under abnormal conditions of the end product. Based on the application, the protective device could be
automatically or manually resettable. Examples of a temperature protective device are single operation de
...