BS EN 60947-4-2:2012 PDF

1   Scope This standard applies to a.c. semiconductor motor controllers and starters, which may include a series mechanical switching device, intended to be connected to circuits, the rated voltage of which does not exceed 1 000 V a.c. This standard characterizes a.c. semiconductor motor controllers and starters with and without bypass means. AC semiconductor motor controllers and starters dealt with in this standard are not normally designed to interrupt short-circuit currents. Therefore, suitable short-circuit protection (see 8.2.5) should form part of the installation, but not necessarily of the a.c. semiconductor motor controller or starter. In this context, this standard gives requirements for a.c. semiconductor motor controllers and starters associated with separate short-circuit protective devices. This standard does not apply to

– continuous operation of a.c. motors at motor speeds other than the normal speed;

– semiconductor equipment, including semiconductor contactors (see 2.2.13 of IEC 60947‑1:2007) controlling non-motor loads;

– electronic a.c. power controllers covered by IEC 60146 series.

Contactors, overload relays and control circuit devices used in a.c. semiconductor motor controll...