Search results for query: *

DanDel - Had flags on the 50/51 Relays Phases A & C. No damage whatsoever on the secondaries. I was probably not clear on that. Failure was definitely on the high side. The trades that work on this were very systematic and conservative about how these new breakers were installed. First the...

DanDel - The transformers were likely never cleaned to our knowledge. However, the environment is ideal in terms of humidity and temperature. The transformer was extremely clean upon inspection. Some background - These tranformers are in the double ended substations and are energized...

peebee - we can't discount anythingat this point but the possibility of the issue of ferroresonance being the issue was raised. That seemed like less of a possibility when we learned that the conductors from brkr to xfrmr on the first failure was about 50 feet. The conductor length for the...

AAK - Yes the transformer was OK with the old breaker. The only thing that had changed was the breaker. The old breakers are an air type of breaker. The new are vacuum type. I gave ColinR a star because his post is tracking what we are hearing from some "experts" regarding these...

Kantor - The new breakers are Cutler-Hammer FC-VR a direct replacement for our Allis-Chalmers type FC breakers. They are 1,000 KVA Dry type transformers the 3 coils stand side by side, they are delta connected with surge arrestors on the primary. AAK - the breaker is opening when the...

We have experienced 2 failures of substation transformers in the last 6 months. We are stumped as to the root cause of these failures and I was hoping some of you tranformer experts out there might have some insight into this problem. System description The facility is a hydro generating...

Thanks for the response electricpete. You're correct the 800v rating is to ground. The meter is hooked up from Hot to Neutral = 277 volts. There is a power resistor on the exterior of the meter that is "open" We've torn apart the meter and there is a smaller power resistor that is...

Maybe some of you generator experts can shed some light on a problem we have with our generator. The generator services a small ski hill with 1 chair lift - off grid. The generator is 480 V, Y and seems to work fine however, we have had problems with keeping a frequency meter operating. We...

Does anyone have any suggestions on sources/reference matls for implementing an astronomical timeclock using a PLC. I have the PLC and numerous 480 volt lighting circuits.