IS 13947 Pt.5/Sec.1-1993 Specification for low voltage switchgear and controlgear Part 5 Control circuit equipment and switching elements Section 1: Electromechanical control circuit equipment
This standard applies to control circuit devices and switching elements intended for control-ling, signalling, interlocking, etc., of switchgear and controlgear.
It applies to control circuit devices having a rated voltage not exceeding 1 000 V a.c. (at a frequency not exceeding 1 000 Hz) or 600 V d.c.
However for operational voltages below 100 V a.c. or d.c, see Note 2 of Sub-clause 4.3.1.1.
This standard applies to specific types of control circuit devices such as:
- manual control switches, e.g. pushbuttons, rotary switches, foot switches, etc.;
- electromagnetically operated control switches, either time-delayed or instantaneous, e.g. con-tactor relays;
- pilot switches, e.g. pressure switches, temperature sensitive switches (thermostats), pro-grammers, etc.;
- position switches, e.g. controi switches operated by part of a machine or mechanism;
- associated control circuit equipment, e.g. indicator lights, etc.
Notes1.. - A control circuit device includes (a) control switch(es) and associated devices such as (an) indicator light(s).
2 - A control switch includes (a) switching element(s) and an actuating system. J - A switching element may be a contact element or a semiconductor element.
It also applies to specific types of switching elements associated with other devices (whose main circuits are covered by other standards) such as:
- auxiliary contacts of a switching device (e.g. contactor, circuit breaker, etc.) which are not dedicated exclusively for use with the coil of that device;
- interlocking contacts of enclosure doors;
- control circuit contacts of rotary switches;
- control circuit contacts of overload relays.
Requirements pertaining to particular types of control circuit devices are dealt with in chap-ters 2 and 3.
Contactor relays shall also meet the requirements and tests of IEC Publication 947-4-1 except for the utilization category which shall comply with this standard.
This standard does not include the relays covered in IEC Publication 255 or automatic electrical control devices for household and similar purposes.
The colour requirements of indicator lights, pushbuttons, etc., are found in IEC Publica-tion 73 and also in Publication 2 of the International Commission of Illumination (CIE).