Three Phase Generator Synchronizing Scheme

[jliu1]

Our project has GE MARK V system for the Generators. Normally we have Single Phase synchronizing scheme. The question is do we need to check other two phases when the phase in the scheme is in synch. The argument is what happened in a previous project, the generator breaker was closed out of phase although the synchronizing system design was proper and all the related equipment functioned as intended. The only plausible explanation for this occurrence is the swapping of the control circuit wires in the PT secondary circuit. Please tell me what you think. Thanks.

 

[peebee]

Single-phase synchronizing should be fine, there is nothing inherently wrong with that concept. Other protective devices, though, such as phase-sequence relays, etc., may be required and may have prevented your problem. Incorrect PT wiring can screw up any protection scheme.

 

[scottf]

I believe single-phase synch check is the norm for most US utilities.

 

[busbar]

With the 1ø scheme, if it synchronized successfully the first time, it should continue to do the same barring any ill-conceived modifications.