ECN Forum Forums General Topics of the Trade General Discussion Area 277 V Unit Heater

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

Is there a chance that there are some Buck/Boost transformers somewhere?

We have done this before for this very situation.

Roger

No Transformer Roger,

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

Thanks

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.

I doubt that you will have any problems but it wouldn't hurt to contact the mfg. to put your mind at ease.
Joe

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...