This part of IEC 60947 applies to the types of equipment listed
in 1.1.1 and 1.1.2 whose main contacts are intended to be connected
to circuits the rated voltage of which does not exceed 1 000 V a.c.
or 1 500 V d.c.
Starters and/or contactors dealt with in this standard are not
normally designed to interrupt short-circuit currents. Therefore,
suitable short-circuit protection (see 9.3.4) forms part of the
installation but not necessarily of the contactor or the
starter.
In this context, this standard gives requirements for:
– contactors associated with overload and/or short-circuit
protective devices;
– starters associated with separate short-circuit protective
devices and/or with separate short-circuit and integrated overload
protective devices;
– contactors or starters combined, under specified conditions,
with their own short-circuit protective devices. Such combinations,
e.g. combination starters or protected starters are rated as
units.
For circuit-breakers and fuse-combination units used as
short-circuit protective devices in combination starters and in
protected starters, the requirements of IEC 60947-2 and IEC 60947-3
respectively apply.