Earth Switch Interlock

[nightfox1925]

Can somebody provide me information whether an earth switch used in switchgears can be fitted with a solenoid wired to external circuit breaker auxiliary contact wherein, the earth switch is blocked (by the shaft driven by the solenoid) when the external circuit breaker is closed.

Is this possible and available in the market? Can anyone provide me links if available?

respectfully...

GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata

 

[desertfox]

HI 02101972

Its a long time since I worked in switchgear however from memory all switchgear units have interlocks between the eartning switches and main breaker, it maybe possible to get an interlock driven by a solenoid it would still have to meet certain requirements ie:- failsafe, if the power to the solenoid driving the interlock failed you should still not be able close the earthswitch with the main breaker in service.
You could try Whipp & Bourne Switchgear, GEC Switchgear or ABB Switchgear they maybe able to help further.

Regards

Desertfox

 

[nightfox1925]

Thanks desertfox. I will keep that in mind.

Respectfully...

GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata

 

[jaynari]

I think it's better to use the beside switch auxiliary contact, coz it will be safe only when equipments are totally apart from the power system.

 

[waross]

One of the safest ways is to use "Kirk" or key interlocks. The first keyed interlock will operate the manual trip on the breaker when the key is removed. That key may be removed and used to operate the second interlock which normally blocks the grounding switch in the open position. The third interlock is blocked when the grounding switch is in the open position. When the grounding switch is closed the third interlock is released and the second key may be removed. This key is used to operate the safety lock on the cubicle door.
respectfully

 

[Zogzog]

Yep, go with the key interlock, that is the best (most common) method.