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#72374 - 11/27/06 05:59 PM 277 V Unit Heater
highground Offline
Member
Registered: 11/14/04
Posts: 53
Loc: 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
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#72375 - 11/27/06 06:11 PM Re: 277 V Unit Heater
Roger Offline
Member
Registered: 05/18/02
Posts: 1716
Loc: N.C.
Is there a chance that there are some Buck/Boost transformers somewhere?

We have done this before for this very situation.

Roger
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#72376 - 11/27/06 06:19 PM Re: 277 V Unit Heater
highground Offline
Member
Registered: 11/14/04
Posts: 53
Loc: Chama, NM
No Transformer Roger,

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

Thanks
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#72377 - 11/27/06 07:02 PM Re: 277 V Unit Heater
RODALCO Offline
Member
Registered: 12/08/05
Posts: 854
Loc: 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.
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#72378 - 11/27/06 07:31 PM Re: 277 V Unit Heater
JoeTestingEngr Offline
Member
Registered: 11/04/05
Posts: 781
Loc: 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
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#72379 - 11/27/06 09:42 PM Re: 277 V Unit Heater
Lostazhell Offline
Member
Registered: 02/21/04
Posts: 1428
Loc: 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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