ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
AreMetal Ladders Ever OK For Electrical Work?
by HotLine1. 01/22/18 07:31 PM
Photocell
by twh. 01/22/18 05:06 PM
VDE 0100 to introduce AFCIs
by sparky. 01/20/18 05:09 PM
MRI LED lights dimmer control replacement - wow!
by Potseal. 01/19/18 08:52 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
0 registered members (), 6 guests, and 8 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Need quick help from a transformer guy #211368
10/08/13 06:20 PM
10/08/13 06:20 PM
S
Steve Miller  Offline OP
Member
Joined: Aug 2001
Posts: 325
Loudoun Cty, VA
We have a 3 phase 208Y120 feed and need to boost to power a single phase 240 unit. I personally have not seen the unit but the guys tell me it's a 'Big Screen' display (scoreboard). The question is: can we use a single BB xfmr and follow the basic 208-240 diagram which basically puts everything in series or do we need 3 BB xfmrs and simply use only 2 of the outputs? My concern is that the 208Y will feed the BB from 2 diff xfmrs. Will it cause a phase shift and cook my (single) BB xfmr?

Work Gear for Electricians and the Trades
Re: Need quick help from a transformer guy [Re: Steve Miller] #211381
10/08/13 09:59 PM
10/08/13 09:59 PM
HotLine1  Offline

Member
Joined: Apr 2002
Posts: 6,919
Brick, NJ USA
Steve:
I do not profess to be a transformer guru, but, I have run a lot of 240 single phase via a BB xfr from 120/208 3 phase 'Y' systems with no issues.

That said, none of the stuff I ran was electronics.

Scott35 & Greg?? Help


John
Re: Need quick help from a transformer guy [Re: Steve Miller] #211386
10/08/13 11:58 PM
10/08/13 11:58 PM
G
gfretwell  Online Content

Member
Joined: Jul 2004
Posts: 9,167
Estero,Fl,usa
I don't see a problem but I am just guessing. All of our equipment would run 208 or 240, either by tapping the input or just that it had a wide enough mouth.
I think it will be seen as just another 1p L/L load.


Greg Fretwell
Re: Need quick help from a transformer guy [Re: Steve Miller] #211413
10/10/13 02:42 PM
10/10/13 02:42 PM
S
Steve Miller  Offline OP
Member
Joined: Aug 2001
Posts: 325
Loudoun Cty, VA
The rest of the story ....
Here's what I didn't know at original post time:
They did cook the BB xfmr (that's why the development of the question about potential for a phase shift that I posted). Seems as tho the board needed 2 hots, neutral and ground because it's basically nothing but a big multiwire ckt and needs the neutral. It came from factory with these 4 tails attached and labeled. The sign guy on top of the ladder told our guy 240 volts ... period. No mention of the neutral and our guy didn't go up and look or question it (strike one). So they hooked up a BB, did not pass the system neutral through (strike two) and fused the primary using the proper fuse size for the secondary (strike three). Guess what smoked. We got lucky it was the xfmr, not the board.
Thanks for the help and we got the guys straight. Nice video board.


Featured:

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

 

Member Spotlight
mxslick
mxslick
Atomic City, ID USA
Posts: 803
Joined: October 2004
Show All Member Profiles 
Top Posters(30 Days)
Admin 21
sparky 15
Potseal 15
Popular Topics(Views)
243,597 Are you busy
180,402 Re: Forum
170,868 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.016s Queries: 15 (0.003s) Memory: 0.9594 MB (Peak: 1.0927 MB) Zlib enabled. Server Time: 2018-01-23 06:11:17 UTC