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Someone suggested to me that I look into a soft start attachment for my heat pump to make it easier on the generator. From looking into it it seems that it slowly ramps things up so there is not a surge when the heat pump starts. Is it worth doing? Would it affect anything under normal operation? I am comfortable around electricity, less so on the control side of a heat pump. It seems that looking this would be installed on the run windings and run capacitor. How complicated would it be for me to install?
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I'll be very interested in the replies to this. I had the question when mine was installed (the heat pump and genny went in at the same time by the same company) and was told that really isn't possible. But the in rush when the heat pump starts up with the generator running really dims the whole house. I usually switch the furnace to gas when we go on the generator for that reason (split system).
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
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01-06-2025, 08:46 PM
(This post was last modified: 01-06-2025, 08:46 PM by crokett™.)
I am going to ask my HVAC guy. I was hoping to get some knowledge here before I talk to him. I see many options online but don't know if it has to be a certain kind of heat pump for this to work.
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01-07-2025, 04:19 PM
(This post was last modified: 01-07-2025, 04:20 PM by MarkSingleton.)
I know they have a "slow start" system for air conditioning units, at least for roof-top units that go onto RVs.
It seems logical that such a thing would be possible for a furnace/heat pump.
Bottom line, I would like to know about this as well.
Mark Singleton
Bene vivendo est optimum vindictae
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A some point I’m going to install a soft start on mine…I’ve got them on the RV, and it makes a huge difference when power is limited.
Probably this one…
https://www.micro-air.com/products_easys...croair.cfm
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I don't have any input on whether you should use one or not but as far as wiring, this is what one I found online shows:
Frank
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Yesterday, 12:55 PM
(This post was last modified: Yesterday, 12:56 PM by Roly.)
(01-06-2025, 12:40 PM)crokett™ Wrote: Someone suggested to me that I look into a soft start attachment for my heat pump to make it easier on the generator. From looking into it it seems that it slowly ramps things up so there is not a surge when the heat pump starts. Is it worth doing? Would it affect anything under normal operation? I am comfortable around electricity, less so on the control side of a heat pump. It seems that looking this would be installed on the run windings and run capacitor. How complicated would it be for me to install?
Make sure the compressor crankcase heater remains powered for cold weather operation. You may be able to look at the heat pump schematics to verify where it gets it power from. Roly
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I am going to ask my HVAC guy tomorrow when he comes out. Last night my wife was complaining about it being cold. Lows for the next few days are ~20. I started thinking it was going to be a thermostat battle until checking it was calling for heat but temps inside were down to 64. The outside unit wasn't running. Following the "when in doubt reboot" action plan I turned off the breakers for a minute or so then turned them back on. The outdoor unit came on but as of about 11 AM today it still hadn't caught up. The upstairs unit has been keeping the upstairs a few degrees warmer and is cycling normally, so it's not that it's too cold. There's something wrong somewhere. The unit is producing some heat, the line outside is almost too hot to touch for very long.
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Are both heat pumps on the generator? If so, are they trying to start simultaneously on the generator? If yes, a 5 minute time delay on power up timer would correct that problem.
Blackhat
Bad experiences come from poor decisions. So do good stories.
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(Yesterday, 12:56 PM)crokett™ Wrote: I am going to ask my HVAC guy tomorrow when he comes out. Last night my wife was complaining about it being cold. Lows for the next few days are ~20. I started thinking it was going to be a thermostat battle until checking it was calling for heat but temps inside were down to 64. The outside unit wasn't running. Following the "when in doubt reboot" action plan I turned off the breakers for a minute or so then turned them back on. The outdoor unit came on but as of about 11 AM today it still hadn't caught up. The upstairs unit has been keeping the upstairs a few degrees warmer and is cycling normally, so it's not that it's too cold. There's something wrong somewhere. The unit is producing some heat, the line outside is almost too hot to touch for very long.
Do you have Aux heat on you units ? If my indoor temp drops about 3 degrees below set temp the 15kw aux heat comes on until set temp is reached. Mine is a whole house heat pump if that makes a difference. No gas service near.
Where the lines enter the indoor coil the line in temp is about 130f and outlet line temp is 80 when outdoor temp is 17 or over. Under 17 it drops a little. It was 8 this morning and inlet was 124f at the coil. Roly
