Bucholtz trip
Bucholtz trip
(OP)
We have a 90MVA, 330/132/13.8KV Y/Y/D transformer.The transformer was used to replace an old one that got burnt while maintaining the old relays and wiring. It is grounded though an earthing transformer via the tertiary winding. Recently the transformer started tripping on bucholtz.Once the relay is reset the transformer can be closed without anything been done on the transformer. Sometimes it will trip while not loaded or even completely isolated. what could be the cause of this, please?






RE: Bucholtz trip
When you say the transformer is tripping even when isolated, it is probable that gas bubbles evolved by the internal fault are slowly collecting in the relay and building up to the trip level.
----------------------------------
Your body may be a temple. Mine is an amusement park...
RE: Bucholtz trip
One was a 75 MVA arc furnace transformer that tripped occasionally when a large overhead crane ( located in the same building ) rolled by.
The second was a large auto-transformer located near railroad tracks that tripped on several ocassions when a locomotive rolled by.
RE: Bucholtz trip
The bucholtz contacts typically go to a "seal in" relay, and the seal in relay contact is in the trip circuit. This seal in unit could also be bad.