BS EN IEC 60947-4-2:2023

Low-voltage switchgear and controlgear. Contactors and motor-starters. Semiconductor motor controllers, starters and soft-starter | Status: Current, Superseded

1 Scope This part of IEC 60947 applies to semiconductor motor controllers, starters and soft-starters which can include a series mechanical switching device, intended to be connected to circuits the rated voltage of which does not exceed 1 000 V AC. This document characterizes semiconductor motor controllers and starters with and without bypass means. This document does not apply to:

• – semiconductor motor controllers and starters used for continuous operation of AC motors at motor speeds other than the normal speed1;
• – electromechanical contactors and external overload relays (see IEC 60947‑4‑1);
• – short-circuit protective device associated with semiconductor motor controllers and starters (see IEC 60947‑4‑1 (MPSD), IEC 60947‑2 and IEC 60947‑3);
• – semiconductor equipment, including semiconductor contactors (3.4.13 of IEC 60947‑1:2020) controlling non-motor loads (see IEC 60947‑4‑3);
• – semiconductor motor controllers and starters used for rotor circuits1;
• – adjustable speed electrical power drive systems (see IEC 61800 series);
• – use of the product within explosive atmospheres (see IEC 60079 series);
• – software and firmware requirements1;

  NOTE 1 Guidance on embedded software is given in IEC TR 63201.

• – cyber security aspects (see IEC TS 63208).

Contactors, overload relays and control circuit devices used in semiconductor motor controllers and starters are considered compliant with the requirements of their relevant product standard. Where mechanical switching devices are used, they are considered meeting the requirements of their own IEC product standard, and the additional requirements of this document. The object of this document is to state as follows:

• – the characteristics of semiconductor motor controllers, starters and soft-starters and associated equipment;
• – the conditions with which semiconductor motor controllers, starters and soft-starters comply with reference to
  1. a) their operation and behaviour in normal and abnormal operating conditions including overcurrent operating conditions;
  2. b) their dielectric properties;
  3. c) the degrees of protection provided by their enclosures where applicable;
  4. d) their construction including safety measures against electric shock, fire hazard and mechanical hazard;
• – the tests intended for confirming that these conditions have been met, and the methods to be adopted for these tests;
• – the information to be given with the equipment, or in the manufacturer's literature.

NOTE 2 For the purpose of this document, the term "controller" is used instead of "semiconductor motor controller".