Yes. besides squirrels. I went for a drive yesterday up into Canada for a
hike up Grouse Mountain. I do that about every month with my girlfriend
north of the boarder in Vancouver. I was at her house in Shaughnessy (posh
part of Vancouver) and I heard a pop that sounded like gunfire. The lights
went out. I went outside looking for what was going on. Then a BC hydro
truck came up and parked under a transformer. I watched him replace a fuse.
When he reconnected it, a huge explosion happened in the transformer (we are
talking Hollywood pyrotechnics here). I thought he was killed, as he was
about two feet from the biggest explosion I ever saw. He was dazed. He
eventually came down and I talked with him. He thought the problem was in
the fuse, not the transformer. He was wrong. He was on his own, no partner.
I could not believe that he was on his own. if he was hurt, he would be on
The explosion was in the transformer. It has been there for a few decades.
Why now? What is the typical failure mode?
Which shows two instances of poor judgment on his part.
1) working without a partner
2) replacing a one-time fuse before checking for a reason for the fuse
It could have been a gradual deterioration. Insulation cracks can be
caused by cosmic ray irradiation (see the darkening of plexiglass
windows), and the heat in the transformer plus mechanical vibration can
gradually exacerbate them. The fuse probably did its job just as the
current started to spike, but not before doing additional damage, which
is what caused the explosion before the second fuse could blow.
Cooling oil additives, then. Heat and strong local fields can
accelerate a host of organic chemical reactions.
> Which shows two instances of poor judgment on his part.
I asked him about that. He said it was BCX hydro policy... (cost cutting???)
I thought the same thing. I would have disconnected the transformer and
replaced it. Perghaps putting the old one up for refurbishment.... Cost
cuytting policy in effect????
Yes! That is what I want to know. how does insulation fail? It was clearly a
short circuit. What I want to know is what are the failure modes of a 27 KVA
to houshold single phase polemount stepdown transformer. Is it a loss of
oil? I saw a lot of oil dripping on fire.
"odin" <[Only registered users see links. ]> wrote in message
news:[Only registered users see links. ]...
Just an idea - if the container had rusted enough over the years to let a
little H2O in, that would account for the initial shorting of the fuse *and*
later the explosion what it boiled from the heat, bursting the can like an
old-time steam boiler and spewing hot (and flammable) transformer oil.
Bit I'm just a chemist. I would suggest you ask a lineman for the power