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[mcarter]

I have a 10kW Generac backup power generator. It is too small I believe to backup my main level 2.5 ton heat pump. I was wondering though, if the furnace blower could be wired separately to the backup generator so that if the power goes out, my wood boiler can still keep the house warm. My OWB is already wired to the backup generator, so the pump will still be operational during power outage.

Can the furnace blower be wired separately? I guess the thermostat would need backup too?

Michael

[RSI]

There are probably a lot of ways to do it.
The first thing that popped into my head is put a relay in series with the thermostat wire that turns the heat pump on and power the relay coil off a circuit that the generator doesn't power.
It would be better probably if you used the normally closed contacts on the relay and power if off the generator but it might be harder to get figured out.

[Bull]

If your heat pump thermostat is set below your owb thermostat temp. the heat pump should not come on during a power outage.

[mcarter]

My current setup is like this:

200 Amp Main Power Service and 10kW Generac backup generator

Main power ---> 60 amp breaker(2 pole)  ---> Carrier Air Handler/Blower/Electric Heat
Main power  ---> 30 amp breaker(2 pole)  ---> Outside Carrier 2.5 ton Heat Pump

Generator ---> 15 amp breaker  ---> OWB water pump
Generator ---> 20 amp breaker(2 pole)  ---> Well pump

I would like to place the Carrier Air Handler on the generator to provide operation of the blower during power outage.  My generator can provide 41 amps at max output.  I realize the generator would not provide enough output for the electric heat grid.  I would like some advice on how I could get my Carrier Air Handler on the generator.

1. Is there a way to separately wire the Blower and place it on the generator panel and leave the Electric Heat connected to the main power?
2. If option 1 is not possible, could I bypass/(or completely disconnect) the electric heat and then place that circuit on the generator panel? (I think the blower draws approx 5 amps?)
3. Install a switch that assures the electric heat will stay off when the generator is operating?

RSI, do you have a rough schematic of the relay option you discussed?

Thanks everyone!

Michael

[Ridgekid]

I agree with Bulls comment.

I too am looking for a setup (backup) for my house and that seems to be the most logical as the heat pump has a sump heater that would need to maintained in cold weather.

[wiseass13]

I would just disconnect it in heat pump. I have heat pump without electric backup and have installed on 2 pole 15 amp. Its wired heavy enough so for resale value of my home i could just install element and upsize breaker.

[jenifer123]

You can put furnace blower on a separate switch, here’s the wiring diagram for furnace switch:

[muffin]

I think the cleanest way would be to add a subpanel.  You could then power that via a breaker from the main panel (2pole break from the main to the sub), or the generator(2pole breaker in the sub).  If you want to spend some dollars, you can get an automatic switch that will cut power from the main panel when a power loss is detected and only allow power from the generator(I think they even switch back when they detect main power is back).  Otherwise you can just do it manually.  Then just put everything you want to run off the generator in the subpanel.

On a side note, I am surprised you cannot run your heatpump off a 10KW generator.  A heatpump should only use about 10 AMPS on 220VAC or about 2KW.  Mayber another 1K for the blower.  Unless you have a huge house with some major power consumers, 10KW should be enough.  Obviously you cannot run the electric elements!