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)
234,857 Are you busy
169,651 Re: Forum
162,893 Need opinion
Who's Online Now
0 registered members (), 55 guests, and 11 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#72374 - 11/27/06 09:59 PM 277 V Unit Heater  
highground  Offline
Member
Joined: Nov 2004
Posts: 53
Chama, NM
I recently went on a service call for some high bays. While up in the lift I noticed the electric unit heaters had 277V nameplates but were installed in a building with 240V. No 277V is available.

(The motors are 277V rated as well)

The customer says they are about two years old?

Any thoughts as to potential problems?


Thanks


Work Gear for Electricians and the Trades

#72375 - 11/27/06 10:11 PM Re: 277 V Unit Heater  
Roger  Offline
Member
Joined: May 2002
Posts: 1,716
N.C.
Is there a chance that there are some Buck/Boost transformers somewhere?

We have done this before for this very situation.

Roger


#72376 - 11/27/06 10:19 PM Re: 277 V Unit Heater  
highground  Offline
Member
Joined: Nov 2004
Posts: 53
Chama, NM
No Transformer Roger,

Small building, panel in sight of heaters.
I checked to see if there was one hiding.

Thanks


#72377 - 11/27/06 11:02 PM Re: 277 V Unit Heater  
RODALCO  Offline
Member
Joined: Dec 2005
Posts: 854
Titirangi, Akld, New Zealand
You won't get you maximum power output for heating.
240 volts is 86 % of 277 volts.
By V²/R you only get 75% of your heating capacity.

For the motors it depends if they have to start a heavy load or not.
If it is only to drive a fan i can't see any problems with it.


The product of rotation, excitation and flux produces electricty.

#72378 - 11/27/06 11:31 PM Re: 277 V Unit Heater  
JoeTestingEngr  Offline
Member
Joined: Nov 2005
Posts: 782
Chicago, Il.
I doubt that you will have any problems but it wouldn't hurt to contact the mfg. to put your mind at ease.
Joe


#72379 - 11/28/06 01:42 AM Re: 277 V Unit Heater  
Lostazhell  Offline
Member
Joined: Feb 2004
Posts: 1,429
Bakersfield, CA (Originally Or...
Only thing I can think of would be a conflict of something meant to run with a grounded phase vs. phase to phase... I'm not sure if this would be an issue in your case though...



Member Spotlight
watersparkfalls
watersparkfalls
Washington...Not DC
Posts: 216
Joined: March 2005
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: 0.015s Queries: 14 (0.003s) Memory: 0.7752 MB (Peak: 0.9215 MB) Zlib enabled. Server Time: 2017-04-28 08:07:27 UTC