Go Back   Science Forums Biology Forum Molecular Biology Forum Physics Chemistry Forum > General Science Forums > Physics Forum
Register Search Today's Posts Mark Forums Read

Physics Forum Physics Forum. Discuss and ask physics questions, kinematics and other physics problems.


Intentionally vague question.

Intentionally vague question. - Physics Forum

Intentionally vague question. - Physics Forum. Discuss and ask physics questions, kinematics and other physics problems.


Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 12-05-2005, 07:14 PM
odin
Guest
 
Posts: n/a
Default Intentionally vague question.



Any thoughts on transformer failure?



Reply With Quote
  #2  
Old 12-05-2005, 08:27 PM
PD
Guest
 
Posts: n/a
Default Intentionally vague question.


odin wrote:

You mean, besides squirrels?
Insulator failure.
PCB breakdown due to heat.

Reply With Quote
  #3  
Old 12-05-2005, 08:38 PM
Smolley
Guest
 
Posts: n/a
Default Intentionally vague question.


"odin" <[Only registered users see links. ]> wrote in message
news:hoqdnecGRMQyDAnenZ2dnUVZ_tOdnZ2d@whidbeytel.c om...

Perhaps all the cooling oil leaked out.


Reply With Quote
  #4  
Old 12-05-2005, 08:51 PM
odin
Guest
 
Posts: n/a
Default Intentionally vague question.

> PCB breakdown due to heat.


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
his own.


The explosion was in the transformer. It has been there for a few decades.
Why now? What is the typical failure mode?


PCBs are all removed from Vancouver of 1972.


Reply With Quote
  #5  
Old 12-05-2005, 09:01 PM
PD
Guest
 
Posts: n/a
Default Intentionally vague question.


odin wrote:

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
to blow.


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.

PD

Reply With Quote
  #6  
Old 12-05-2005, 09:10 PM
odin
Guest
 
Posts: n/a
Default Intentionally vague question.

> 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.


Reply With Quote
  #7  
Old 12-05-2005, 09:53 PM
Paul Mays
Guest
 
Posts: n/a
Default Intentionally vague question.

Pauls' Axiom # 13 ...

If Man Made it ... It will break...


"odin" <[Only registered users see links. ]> wrote in message
news:hoqdnecGRMQyDAnenZ2dnUVZ_tOdnZ2d@whidbeytel.c om...


Reply With Quote
  #8  
Old 12-06-2005, 01:06 AM
tadchem
Guest
 
Posts: n/a
Default Intentionally vague question.


"odin" <[Only registered users see links. ]> wrote in message
news:[Only registered users see links. ]...

fuse.
are
partner.

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
company.


Tom Davidson
Richmond, VA



Reply With Quote
  #9  
Old 12-06-2005, 02:05 AM
Double-A
Guest
 
Posts: n/a
Default Intentionally vague question.


tadchem wrote:


Hope it wasn't PCB enriched oil!

Double-A

Reply With Quote
  #10  
Old 12-06-2005, 02:15 AM
operator jay
Guest
 
Posts: n/a
Default Intentionally vague question.


"odin" <[Only registered users see links. ]> wrote in message
news:hoqdnecGRMQyDAnenZ2dnUVZ_tOdnZ2d@whidbeytel.c om...

If you ask on alt.engineering.electrical there are a number of power /
utility types who might be able to give you some.

j


Reply With Quote
Reply

Tags
intentionally , question , vague


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
question about phenol/water saturated solution Z.L. K Protocols and Methods Forum 2 02-11-2008 01:05 AM
Question about Hypothetical Type of Thermal Injury. Explained Radium Protein Forum 13 12-19-2005 09:32 PM
Just a big question... rahemanvelji@yahoo.ca Physics Forum 8 05-09-2005 08:44 PM
Sci.chem FAQ - Part 1 of 7 Bruce Hamilton Chemistry Forum 0 01-15-2004 09:06 AM


All times are GMT. The time now is 08:58 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2005 - 2012 Molecular Station | All Rights Reserved
Page generated in 0.16948 seconds with 16 queries