scope:

Scope and object

This part of IEC 931 is applicable to both capacitor units and capacitor banks intended to be used, particularly, for power-factor correction of a.c. power systems having a rated voltage up to and including 1000 V and frequencies 15 Hz to 60 Hz.

This part of IEC 931 also applies to capacitors intended for use in power filter circuits. Additional definitions, requirements, and tests for filter capacitors are given in annex A.

Additional requirements for capacitors protected by internal element fuses, as well as requirements for the same, are given in IEC 931-3.

The following capacitors are excluded from this pari of IEC 931:

- Shunt power capacitors of the self-healing type for a.c. systems having a rated voltage up to and including 1000 V (IEC 831).

- Shunt capacitors for a.c. power systems having a rated voltage above 1000 V (IEC 871).

- Capacitors for inductive heat-generating plants operating at frequencies between 40 Hz and 24 O00 Hz (IEC 110).

- Series capacitors (IEC 143).

- Capacitors for motor applications and the like (IEC 252).

- Coupling capacitors and capacitor dividers (IEC 358).

- Capacitors to be used in power electronic circuits (IEC 1071).

- Small a.c. capacitors to be used for fluorescent and discharge lamps (IEC 1048 and IEC 1049).

- Capacitors for suppression of radio interference (under consideration).

- Capacitors intended to be used in various types of electrical equipment and thus con side red as components.

- Capacitors intended for use with d.c. voltage superimposed on the a.c. voltage.

Accessories such as insulators, switches, instrument transformers, fuses, etc., are to be in accordance with the relevant IEC standards.

a) to formulate uniform rules regarding performances, testing and rating;

b) to formulate specific safety rules;

c) to provide a guide for installation and operation.