We're installing receptacles for 120 volt roof heating (snow melting) cables. These must be GFCI protected. We're having some discussion on how to wire these up.

What I want to do is install split duplex receptacles on the eave, and have 2 heating cable on each receptacle. Each of these receptacles will be protected by a double pole GFCI breaker. This way we will only need to run a 3-wire to each receptacle and split the hot tie-bar.

The argument is, if the wattage of 2 heating cables in one receptacle are different, will the GFCI trip? One of my employees thinks the load needs to be balanced and the heating cables each need to be on their own single pole GFCI breaker.

I disagree - I say regardless of what either load is, the neutral will carry the unbalance, and the GFCI won't "see" the difference. The GFCI breaker should act the same as if it were protecting a hot-tub, where the heating load is on 240 volt and the pump, lights, etc are on 120 volts.

Am I correct? I want to ensure this will work before we install the wiring next week.


Sixer

"Will it be cheaper if I drill the holes for you?"