Can my generator run my home aircon (heat pump)?

[corn18]

TLDR: Will my 7000W (10,500 surge) generator run my 3 ton heat pump?

I have a 7000W genset with a NEMA L-14-30 connector. This is what the manual says "This receptacle powers 120/240 Volt AC, 60 Hz, single phase
loads requiring up to 7,000 watts of power (7.0 kW) at 29.1 Amps for 240 Volts or two independent 120 Volt loads at 29.1 Amps each. The outlet is protected by a two pole rocker switch circuit breaker."

This connects to my house via a NEMA SS2-50P input that goes to a sub-panel in the house. The subpanel has all 120V stuff on it except the aircon. That is hooked up but the electrician told me to turn it off before I flip the sub-panel over to the generator (not an auto switch).

I got this Emporia Vue energy monitor and it says the 3 ton heat pump draws 2000W sustained. Not sure what the surge is but the max amps on the placard says 18.1A @ 230V. So that is 4,163A. I would think my 7000W (10,500 surge) genset could handle that.

I am afraid to just try it. I could do it right now but don't want to fry the aircon. I feel stupid asking this. Whadya think?

 

[ricardocello]

Does the placard have an Amp rating for LRA (locked rotor amps)?

 

[corn18]

This is the placard.

 

[ricardocello]

LRA is 72.2A, which means surge power needed is 17,328 W!!
The generator will either trip its breaker, or the engine will stall hard.

They make soft start devices (e.g., EasyStart 368) to bring this number way down, it might just get it started.
You’ll still notice a drag on the generator when it starts.

Search the forum for EasyStart and soft start.

 

[sunshine_eggo]

EasyStart™ 368 Soft Starter

The EasyStart™ soft start motor starter supports 115 & 230V A/C motors & employs a 4-part start ramp sequence that offers the lowest possible start-up current.

www.microair.net

 

[corn18]

Coolio, gonna order one up now.

 

[ricardocello]

Coolio, gonna order one up now.

The problem is that you won’t know if it will work until after you buy it. Beware.
But it’s really the best you can do.

 

[corn18]

The problem is that you won’t know if it will work until after you buy it. Beware.
But it’s really the best you can do.

It'll be here on Wednesday.

The Amazon reviews had data from users that said the startup amps went from 78 to 25. I've been eying a bigger genset for the house anyway so if it doesn't work, I have an excuse to buy a new genset. Even if it does work with this genset, I might get a new one anyway.

 

[sunshine_eggo]

With the 10kW surge, that puts you at 41A. The soft start claims 75% reduction, and you only need about 50% reduction. I really suspect you'll get there.

IIRC, the install process involves iterative start attempts for the device to determine the optimal current. I would complete the installation with grid before I switched to genny.

 

[ricardocello]

I would complete the installation with grid before I switched to genny.

You have to wait for 5 startup cycles for it to learn. If you got the bluetooth version you can talk to it and see how it did.

 

[corn18]

You have to wait for 5 startup cycles for it to learn. If you got the bluetooth version you can talk to it and see how it did.

I did get the BT version.

 

[corn18]

I am amazed that my RV 15k BTU aircon draws 1600W steady state and my 36k BTU house heat pump is only 2000W.

 

[ricardocello]

The app isn't great, but you know, i've got two of these running right now, I think I'll check them.
First 90+ degreee F day of the year.

By the way, if the compressor isn't running, you can't talk to it. Wait until it is running.

 

[time2roll]

No harm to try once.

 

[time2roll]

LRA is 72.2A, which means surge power needed is 17,328 W!!
The generator will either trip its breaker, or the engine will stall hard.

OK and just below says 18.6 amp circuit is fine.

 

[ricardocello]

OK and just below says 18.6 amp circuit is fine.

surge only lasts for a second or so, breaker is sized on continuous current

 

[ricardocello]

ProTip for east coast pollen sufferers: Your HVAC is also suffering, hose down the outside coil and get that pollen off!

Here is my ancient Carrier.
Reduced LRA from 83.0 to 25.2A on the last start.

 

[ricardocello]

And here is my less ancient York.
Reduced from 96.7 (!) to 22A (wow).

 

[chrisski]

EasyStart™ 368 Soft Starter

The EasyStart™ soft start motor starter supports 115 & 230V A/C motors & employs a 4-part start ramp sequence that offers the lowest possible start-up current.

www.microair.net

It'll be here on Wednesday.

The Amazon reviews had data from users that said the startup amps went from 78 to 25. I've been eying a bigger genset for the house anyway so if it doesn't work, I have an excuse to buy a new genset. Even if it does work with this genset, I might get a new one anyway.

Might want to open the AC and see what is installed AC first. You could have a Hard Start or Easy Start. If you open it up and you have one capacitor only, It's Easy Start ready. If you have two or more capacitors, I would say it's not easy start ready and probably has a hard start kit installed.

Hard Start kits are quite common. I don't know if it comes from the factory that way, or if over the years it's an up sale with yearly Maintenace.

I went to install an Easy Start on my AC unit, and low and behold when I opened mine up for the install, I did not see one Capacitor, I saw a capacitor with a hard start kit attached and two more capacitors on top of that. I opted not to install the easy start kit.

 

[corn18]

This is the genset I'm ogling right now. The place where I put the genset outside is right next to the gas meter. Would be super cool to have it hooked to natural gas and not worry about getting gas.

Westinghouse 14,500-Watt/11,500-Watt Remote Start Tri-Fuel Portable Generator with Transfer Switch Outlet, Remote Start and CO Sensor WGen11500TFc - The Home Depot

The Westinghouse WGen11500TFc Tri-Fuel Portable Generator with CO Sensor produces up to 14,500 peak watts and 11,500 running watts, the WGen11500TFc is a tri fuel generator that operates on gasoline, propane (LPG), or natural gas. The heavy duty 550cc 4-Stroke OHV Westinghouse Engine is...

www.homedepot.com