ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Potseal 11
Recent Posts
Electrode boilers question
by annemarie1. 04/27/17 01:40 PM
Why cables look like they do
by LongRunner. 04/26/17 09:36 AM
Dimmable LED 2x4 lay in fixtures
by HotLine1. 04/24/17 05:43 PM
Old decora style outlets
by Lostazhell. 04/22/17 07:59 PM
Permit Snafus...AHJs and Contractors Jump in
by gfretwell. 04/22/17 01:11 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
234,885 Are you busy
169,683 Re: Forum
162,919 Need opinion
Who's Online Now
1 registered members (George Little), 56 guests, and 8 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#130374 - 03/18/06 08:57 AM Transformer Banks  
Dnkldorf  Offline
Member
Joined: Dec 2004
Posts: 1,064
nowhere usa
I am doing a line diagram for the machine shop in earlier threads, and on their only print they have, it shows the sub station and the (2) 4160 services. The first one is cut and dry, it shows a 600Kva 460V dry transformer in the back, but it is really a 600Kva 440V...Not the problem..

The problem lies with the 208V side. There are 3 "pot" transformers making up the service, not 1 big transformer like the 440V side.
The print states, (3) Pot 100kva..
The service has parallel 500MCM pulled in to the MDP.

Is it safe to assume that this really is a 300KVA 208V service? They are additive aren't they?


So this would ponder the thought that a 45Kva 3 ph transformer is really (3) 15Kva cores?

Dnk...

[This message has been edited by Dnkldorf (edited 03-18-2006).]


Tools for Electricians:

#130375 - 03/18/06 10:05 AM Re: Transformer Banks  
WFO  Offline
Member
Joined: Sep 2005
Posts: 202
Cat Spring, TX
Yes, they are additive. Three 100 Kva transformers hooked together in a bank would constitute a 300 Kva bank.

And yes, a 3 phase transformer is essentially 3 in 1. The core is common to all three.

Think of the core as a digital LCD figure "8" like you would see on an alarm clock except that it is on its side. Each of the three vertical legs would have a winding on it, but it is still essentially a single core since all three are bridged top and bottom.

There is another core design called "shell" which is similar to the above, except that it is taken a step further and the core comes around the outside two phases, so each phase is completely surrounded by a steel core. This is usually used in the larger units.

[This message has been edited by WFO (edited 03-18-2006).]


#130376 - 03/18/06 12:40 PM Re: Transformer Banks  
XtheEdgeX  Offline
Member
Joined: Apr 2005
Posts: 116
Florida
They are additive, but on a line diagram, I would note them as separate, or being a bank, as you stated in your post " (3) Pot 100kva".


#130377 - 03/18/06 01:42 PM Re: Transformer Banks  
Dnkldorf  Offline
Member
Joined: Dec 2004
Posts: 1,064
nowhere usa
Thanks Fellas... [Linked Image]


Dnk..



Member Spotlight
Posts: 362
Joined: April 2003
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.012s Queries: 15 (0.002s) Memory: 0.7598 MB (Peak: 0.8897 MB) Zlib enabled. Server Time: 2017-04-28 19:42:23 UTC