scope:

Scope and object

This part of IEC 143 covers protective equipment for series capacitor banks, with a size larger than 10 Mvar per phase. Protective equipment is defined as the main circuit apparatus and ancillary equipment, which are part of a series capacitor installation, but which are external to the capacitor part itself. The recommendations for the capacitor part are given in IEC 143. The protective equipment is mentioned in clauses 1.3 and 7.6 of IEC 143.

The protective equipment, treated in this standard, comprises the following items listed below.

- overvoltage protector,

- protective spark gap,

- non-linear resistor (varistor),

- by-pass circuit-breaker,

- disconnectors,

- current-limiting damping equipment,

- discharge reactor,

- voltage transformer,

- current transformer,

- signal column,

- relay protection, control equipment and platform to ground communication equipment.

The object of this standard is:

- to formulate uniform rules regarding performance, testing and rating,

- to illustrate different kinds of overvoltage protectors,

- to provide a guide for installation and operation.