ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
by HotLine1. 03/22/18 09:08 AM
Recall notice: Southwire wi-fi wall switches
by sparkyinak. 03/15/18 06:03 PM
Goodman Manufacturing Recalls Modular Blowers
by Admin. 03/13/18 10:40 PM
MAAX Spas Recalls Hot Tubs and Swim Spas
by Admin. 03/13/18 10:29 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
0 registered members (), 13 guests, and 8 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
300KVA Transformer photos #163767
05/16/07 04:24 PM
05/16/07 04:24 PM
Admin  Offline
Joined: Oct 2000
Posts: 3,495

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.

[Linked Image]

[Linked Image]

[Linked Image]

[Linked Image]

[Linked Image]

Tools for Electricians:
Re: 300KVA Transformer photos [Re: Admin] #163768
05/16/07 05:41 PM
05/16/07 05:41 PM
CTwireman  Offline
Joined: Feb 2002
Posts: 840
Connecticut, USA
There could be a slight problem with that. wink

Re: 300KVA Transformer photos [Re: CTwireman] #163780
05/16/07 09:04 PM
05/16/07 09:04 PM
frenchelectrican  Offline
Joined: Feb 2003
Posts: 939
Wi/ Paris France { France for ...
Ahh good catch there.

i am suprised that it did not trip the OCPD yet shocked

Merci, Marc

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

Re: 300KVA Transformer photos [Re: frenchelectrican] #163790
05/17/07 07:49 AM
05/17/07 07:49 AM
RODALCO  Offline
Joined: Dec 2005
Posts: 856
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.
Re: 300KVA Transformer photos [Re: RODALCO] #164109
05/25/07 01:48 AM
05/25/07 01:48 AM
mxslick  Offline
Joined: Oct 2004
Posts: 803
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!

Re: 300KVA Transformer photos [Re: mxslick] #164494
06/04/07 06:56 PM
06/04/07 06:56 PM
yaktx  Offline
Joined: Feb 2003
Posts: 288
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?

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

Joined: Apr 2002
Posts: 6,936
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.

Re: 300KVA Transformer photos [Re: HotLine1] #164553
06/06/07 03:36 AM
06/06/07 03:36 AM
e57  Offline
Joined: May 2003
Posts: 2,876
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


2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Posts: 264
Joined: February 2013
Show All Member Profiles 
Top Posters(30 Days)
Admin 5
Trumpy 5
Popular Topics(Views)
244,547 Are you busy
181,672 Re: Forum
171,719 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.031s Queries: 15 (0.005s) Memory: 0.9950 MB (Peak: 1.1561 MB) Zlib enabled. Server Time: 2018-03-22 15:25:47 UTC