Page 7 - Gas insulated Switchgaer

Interlocks

กลไกอินเตอรล็อคของ three-position switch และ circuit-breaker ภายในตู

สวิตชเกียรฯ ตองมีคุณสมบัติ ดังนี้:

1. Operation of three-position switch cannot be selected as long as the

circuit-breaker is closed. The selection “operate three-position switch” locks

out the circuit-breaker.

2 .Selecting “disconnector function” or “earthing switch function” only

releases the operating shaft for the associated switching operation. The

operating lever can not be removed until the switching operation has been

completed.

3 .“Operate three-position switch” can not be completed until the

operating lever has been removed.

4. Feeder earthing (three-position switch to EARTH and circuit-breaker

ON) is secured against de-earthing. Electrical connections to the releases are

interrupted by auxiliary contacts of the

three-position switch in EARTHED position.

Local mechanical opening of the circuit-breaker

can be blocked. This is made by blocking the

tripping latch, which also prevents the

circuit-breaker from being tripped by other external effects.