Transformer popping noise
Transformer popping noise
(OP)
Recently, a 1MVA 12470-4160 oil filled pad mount transformer was energized after being out of service for about 1 month (no changes or maintenance, just de-energized). The unit was energized (no load, just secondary cables) and soon started to "pop" or "thump". This sounded odd so the unit was de-energized within 5 minutes. Has anyone experienced this, as odd as it sounds (to me), it was similiar to the sound of metal thermally expanding or contracting, but coming from inside the transformer. A PI was immediately performed on both windings, both >2. Any ideas what would cause this noise?
Thanks.
Thanks.






RE: Transformer popping noise
RE: Transformer popping noise
On a side note, curious if an intermitant fault on the transformer secondary (i.e. cables/switchgear), (too low to operate the protective device or before the pd), have the ability to cause a disturbance such as this inside the transformer.
RE: Transformer popping noise
I was in submarine service, and when we dove the hull would make popping noises like that, scared the crap out of the new guys everytime.
RE: Transformer popping noise
RE: Transformer popping noise
1) Overfluxing - Check the incoming breaker for any arcing contacts.If possible use another breaker.
2) Any loose mechanical part eg tie-rods
3) Core clamping going down resulting in loose core laminations
4) Moisture getting inside insulation and partial discharge occurring inside press board.
RE: Transformer popping noise
RE: Transformer popping noise
Regards
Marmite
RE: Transformer popping noise
Rafiq Bulsara
http://www.srengineersct.com
RE: Transformer popping noise
Keith Cress
kcress - http://www.flaminsystems.com
RE: Transformer popping noise
RE: Transformer popping noise
p.s. the faulted cables were replaced and the transformer sounds fine now.
RE: Transformer popping noise
When a transformer is energized, there is an inrush current due to the difference in core residual magnetization and the newly applied system voltage for a few cycles before the core flux and back e.m.f. stabilize. The initial change in magnetizing current and resulting core flux may occur more rapidly than the final steady state magnetizing flux and so will the mechanical stresses (magnetostriction, etc.) experienced by the core. This can produce a 'pop' or thump sound.
Normally a transformer experiences this effect once at energization. But in the case of a faulty contact, cable or other system problem that momentarily removes system voltage from the winding, its reapplication will behave in a similar manner to a normal inrush event.
RE: Transformer popping noise
This is the situation when geo-magnetically induced DC currents enter transformer during sun storms,resulting in booming sound from transformers.