ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Calling all Non-US members!! (Non-US only)
by Bill Addiss. 08/13/18 05:52 PM
Upgrade the old panel
by gfretwell. 08/13/18 12:20 AM
depth of duckbank
by ghost307. 08/12/18 09:26 PM
Section 179 vehicle purchases
by BigB. 08/05/18 01:06 PM
Don't you buy this stuff
by BigB. 08/05/18 01:00 PM
New in the Gallery:
Plug terminals
Housebilding DIY wiring
Who's Online Now
0 registered members (), 2 guests, and 19 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Transformer Banks #130374
03/18/06 08:57 AM
03/18/06 08:57 AM
D
Dnkldorf  Offline OP
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:
Re: Transformer Banks #130375
03/18/06 10:05 AM
03/18/06 10:05 AM
W
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).]

Re: Transformer Banks #130376
03/18/06 12:40 PM
03/18/06 12:40 PM
X
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".

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


Dnk..


Featured:

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

 

Member Spotlight
Alan Belson
Alan Belson
Mayenne N. France
Posts: 1,803
Joined: March 2005
Show All Member Profiles 
Top Posters(30 Days)
Popular Topics(Views)
248,548 Are you busy
186,243 Re: Forum
175,723 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.018s Queries: 14 (0.005s) Memory: 0.9595 MB (Peak: 1.0891 MB) Zlib enabled. Server Time: 2018-08-16 08:11:57 UTC