The following quote was originally posted here: http://forums.mikeholt.com/showthread.php?t=104381
You made this post about 10 years ago, and it doesn't look like you've posted in a few years. Still, if this message finds you I could use some help. When I installed generators I would always use a 60-100 amp contactor to manage the load of heat pump systems. Generally the heat pump and blower would operate, depending on available capacity, but if the strip heat comes on the whole system will drop out. I know its preferable to just lock out the strips, since the heat pump will still provide some heat, even when its very cold outside. I never did that because it requires getting a wire from the ATS to the furnace, which usually isn't feasible. The company I work for now has just developed a wireless device designed to interrupt 24VAC control circuits. My question is, which stat wire am I looking for to just drop the strips? Any help is appreciated.I install a relay that locks out the emergency heat (the heat strips)(this can be done by a relay powered by generator only breaking the control wire for the heat strip relay from the t'stat) so the load is compressor/fan only. If it gets cold enough that the compressor locks out their SOL. Usually try to talk them into a small gas wall heater for emergency heat.