Powering of 5.0 MVA 11/22 kV transformer
Powering of 5.0 MVA 11/22 kV transformer
(OP)
Hi,
The utility supply is planning to power a 5.0 MVA transformer without the basic temperature and Bucholtz protection . The transformer will only be protected by overcurrent and earth fault protection .
Is it a sound practice ?
Bob






RE: Powering of 5.0 MVA 11/22 kV transformer
(1) The gas collection device can sense an incipient (or developing) fault and caution the operator in advance.
(2) The surge device is very reliable in detecting a fault in the transformer and also is fast acting.
If a transformer is in service without Buchholz protection, it is certainly a compromise and cannot be said to be good engineering practice.
Having said that, the Buchholz and temperature sensing devices are transformer mounted and it is to be seen on case to case basis if there are any difficulties in wiring the signals to the remote breaker / switchgear room.
Hope the above is helpful.
RE: Powering of 5.0 MVA 11/22 kV transformer
"Fuses are comonly used to provide fault detection for transformers with minimum nameplate ratings up to 5000 kVA, three phase (Category I and II). Transformers larger than 5000 kVA, three phase, minimum nameplate (Category II and IV) are generatlly protected by a combination of potective devices..."
RE: Powering of 5.0 MVA 11/22 kV transformer
There are many, many 5 MVA transformers in service with only primary fuses for protection.