ECN Forum Forums Code Related Discussion NEC & other Code issues 277Volt single phase Motors

Why isn't there an Amperage chart on theses motors in the code book???
430.248 just goes up to 230 volts???

Personally,I have never seen a 277V motor.
So I never gave it a thought.

Ditto on Leland's comment.

You could always refer to the motor nameplate, right?

Per 430.6 (A)1 all amperages except for overloads & few exceptions are to come out of tables in Code book.
Since no Table with 277V I guess well have to use Nameplate for all calculations??
And yep theres 277Volt Motors Goggle um there there. These are on a Heat Pump System.

I've seen those and other type units. Also in them was a transformer to step down.

Google was the first thing I did. Always nice to find something new.

Been in the trade almost 45 years have Never before this time ever Seen or Knew there were 277 volt mtrs. Guess never to late to learn right.

It's never to late, & we're never to old to learn. We come here to do that, right???

Yes, as there is no table to use, go to 110.3 (B) and use the nameplate.

There is not a large number of 277 volt motour in use however most common found in HVAC or large electric unit heater AKA electric Renzor heater.

Once a while will find them on the exhaust fan when they are tied to bathroom lighting circuit { this is a grey spot to cross }

The other common place to find 277 volt motor is thru wall heatpump when they are order on 277 volt system.

Merci,Marc