Automatic electrical controls - Part 2-22: Particular requirements for thermal motor protectors

This clause of Part 12 is applicable except as follows:

1.1 Replacement:

This part of IEC 60730 applies to the partial evaluation of thermal motor protectors as defined in IEC 60730-1 for household and similar use, including heating, air conditioning and similar applications as well as for sealed (hermetic and semi-hermetic type) motor-compressors.

NOTE A thermal motor protector is considered an integrated control since its protective functionality is dependent on the correct mounting and fixing in or on a motor and which can only be fully tested in combination with the relevant motor. This dependency is illustrated by:

• the ability of the thermal motor protector to accurately and reliably sense the heat of the motor windings; thus, addressing the over-temperature protection due to motor overload conditions;

• the ability of the thermal motor protector to accurately and reliably sense the current due to motor locked-rotor conditions; thus, reducing the response time and not being adversely affected by heat-sink at the assembly spot in the application;

• the influence of the motor’s electromagnetic field on the switch behaviour of the thermal motor protector; particularly, affecting the arc direction between the contacts resulting in uneven wear of the contact material and eventually leading to failure of operation.

Requirements concerning the testing of the combination of sealed (hermetic and semi-hermetic type) motor-compressors and thermal motor protectors are given in IEC 60335-2-34.

This standard applies to thermal motor protectors using NTC or PTC thermistors, additional requirements for which are contained in Annex J.

1.1.1 This standard applies to the inherent safety, to the operating values, operating times, and operating sequences, where such are associated with equipment safety, and to the testing of thermal motor protectors used in or on household or similar equipment as well as sealed (hermetic and semi-hermetic type) motor-compressors.

This standard applies to thermal motor protectors for appliances within, but not limited to, the scope of IEC 60335-1 and its Part 2’s.

NOTE Throughout this standard, the word “equipment” means “appliance and equipment”.

Thermal motor protectors not intended for normal household use, but which nevertheless may be used by the public, such as equipment intended to be used by laymen in shops, in light industry and on farms, are within the scope of this standard.

This standard does not apply to thermal motor protectors designed exclusively for industrial applications.

1.1.2 This standard does not apply to other means of motor protection.

1.1.3 This standard does not apply to a manual device for opening the circuit.