Although very infrequent, I have experienced spurious tripping of power tranformers upon energization via their differential relays (restrained trip). These are generator step-up transformers (80-90MVA, 1998-2000 vintage) at natural gas fired generation facilities. The differential relays are...
Samboy,
If I was the owner of this transformer, I would require a field test for the excitation current. The excitation test is one of many tests typically used to verify the overall "health" of the transformer. It is typically done each time a large power transformer is tested. As with most...
ahung,
We also have W501D5 with Brush machines. We have a FUJI generator breaker with redundant trip coils, and Beckwith generator protection.
I would be inclined to at least borescope the surface of your rotor and look for evidence of heat or arcing as byrdj describes above. Also look...
Engcan,
Your 15 amp breaker should trip on a ground fault, assuming the wiring in your 120V single phase system is done properly. By this, I mean if the secondary of the 240/120V system is grounded, and the continuity of the grounding conductor system is maintained to the point of the ground...
This is a pretty common problem. As long as your liquid gage shows a normal oil level, you should be ok.
Support your cables to relieve the strain on the bushings, and carefully torque the bolts on the bushings.
The bucholtz relay can trip due to sudden oil flow between the transformer tank and conservator tank, or due to gas accumulation. Typically the gas can be purged (for analysis) to clear the relay. Check to make sure these trip contacts are in the correct state. We have seen these bucholtz...
