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#163767 - 05/16/07 01:24 PM 300KVA Transformer photos
Webmaster Offline


Registered: 10/07/00
Posts: 3142
Loc: NY, USA

I have viewed your website a lot of times and watched in amazement at some of what is posted. I'd rather watch, however, a transformer started making some funnny noise when I was on site, and I de-energized it without permission. Attached are some of the photos, pay close attention to phase A.

Dennis W.

Tools for Electricians:
#163768 - 05/16/07 02:41 PM Re: 300KVA Transformer photos [Re: Webmaster]
CTwireman Offline

Registered: 02/07/02
Posts: 839
Loc: Connecticut, USA
There could be a slight problem with that. ;\)

#163780 - 05/16/07 06:04 PM Re: 300KVA Transformer photos [Re: CTwireman]
frenchelectrican Offline


Registered: 02/06/03
Posts: 938
Loc: Wi/ Paris France { France for ...
Ahh good catch there.

i am suprised that it did not trip the OCPD yet \:o

Merci, Marc
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)

#163790 - 05/17/07 04:49 AM Re: 300KVA Transformer photos [Re: frenchelectrican]

Registered: 12/08/05
Posts: 862
Loc: Titirangi, Akld, New Zealand
Good call to shut it down.

Looks like a loose connection in that jumper, overheated and arced away the flat tab of the lug and terminal of the TX.


The product of rotation, excitation and flux produces electricty.

#164109 - 05/24/07 10:48 PM Re: 300KVA Transformer photos [Re: RODALCO]
mxslick Offline

Registered: 10/24/04
Posts: 785
Loc: Atomic City, ID USA
Dennis W:

A question: Can you describe the "funny noise"? I have a theatre with a similar Tx that makes a peculiar high-pitched buzz/whine..didn't notice any burning smells but it sure is loud!

#164494 - 06/04/07 03:56 PM Re: 300KVA Transformer photos [Re: mxslick]
yaktx Offline

Registered: 02/19/03
Posts: 286
Loc: Austin, Texas, USA
Good call. I'd say that transformer would be pretty noisy anyway, what with the hard-piped connections. I'd guess the funny noise would be something other than 60Hz plus harmonics, no?

#164503 - 06/04/07 04:47 PM Re: 300KVA Transformer photos [Re: yaktx]
HotLine1 Offline


Registered: 04/03/02
Posts: 6791
Loc: Brick, NJ USA
For a 300KVA xfr, the secondary conductors seem a little on the wimpy side??

300KVA is usually 800 amp secondary MOCP @ 208 volt, 3 phase.

Oversized xfr?? Not that it matters now, but I'm curious.

#164553 - 06/06/07 12:36 AM Re: 300KVA Transformer photos [Re: HotLine1]
e57 Offline

Registered: 05/27/03
Posts: 2837
Loc: S.F.,CA USA
Ah, I have seen this before - the "Melti-tap" transformer.

When I was younger and far stupider than I am today. I did a service call for mixed voltages at a supermarket, and went all over trying to find the place that had a neutral - all the way back to the transformer and pulled the cover off (LIVE - DUMB) to find a glimering molten pool of Aluminum. Do ya know that feeling like you're looking at a nest of angry hornets close up? "I'll just put this cover back on with 2 screws, and get away from this fast..."
Mark Heller
"Well - I oughta....." -Jackie Gleason


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