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#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: 790
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: 1,431
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...



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