Synch check 1

[samreen]

In case when line is energize but bus is dead..whether synch check will be completed with dead bus and live line ?
Do CB closes in this condition?

 

[GTstartup]

it will if your synch check is set to allow it. Check the settings.

 

[ScottyUK]

You really should consider some interlocking so that 'dead bus' is not a condition which can accidentally occur because someone left the VTs isolated.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[slavag]

Hi.
In case of voltagecheck ( live-dead or dead-dead) as Scotty saied you have check additional criterions as :
1. MCB (fuses) OK
2. All other feedeng breakers are opened.
Best Regards.
Slava

 

[rbulsara]

Permissive to close on a dead bus is a separate logic from the Synch check. Since synch check permissive contact will not close with a dead bus (as there is no synch) you need either a hardwired or software (if programmable) logic to bypass the synch check relay on a dead bus. You also need to have a logic in place that prevents closing on a dead bus which is dead because of a fault! If any of the source breakers have a bell alarm (open due to overcurrents) you need to lock out the bus.

 

[slavag]

Hello.
Newer synchrocheck relays are include voltagecheck option too.
Usually is include some binary input: dead bus (DB)release.
Possible add to this contact any logic.
In case of protection operated, latch contact add directly (in series) to the close coil. Ofcourse in case of autoreclosere functionality only afterfinally trip.
Best Regards.
Slava

 

[cvejicv]

Of course - u can close CB. How could u energize S/S (bus bar) if u don't close breaker?
You can choose - if it is request of Grid department, than through Sync logic - close CB when:
DL-DB
DL-LB
LL-DB
LL-LB (volt, angle, freq condition - are in setting region)

(AND if no VT MCB trip, interlock, voltage not in DEAD zone - conditions are fulfilled)