Fixed MV Circuit Breaker 1

[Guardiano]

Dear Forum Members,
I understand that the only means to safely isolate a medium voltage circuit breaker is to take it out and padlocked it in the test position. What about fixed circuit breakers? Could the spring charged mechanism be used to safely isolate a fixed circuit breaker? A circuit breaker which is not charged to a ready to close position would basically not close. Any insight?
Guardiano

 

[beyond86]

In this case, should be installed isolation switches (disconnector) series with a breaker.

 

[LionelHutz]

A vacuum breaker can't be used as safety isolation no matter how you lock out the mechanism. An upstream breaker needs to be racked out or there needs to be a switch in series.

 

[Guardiano]

What about SF6?

 

[pwrengrds]

same rules apply, physical open space is required.

 

[beyond86]

In GIS must be installed a guaranteed indicator of position of isolated switch.

 

[dpc]

At least in the US, a "visible break" is required. And probably shorts and grounds in many cases. "If it isn't grounded, it isn't dead."