We are planning on installing an interlock kit on our panel to use a portable generator during power outtages, so I'm checking to see if we're able to run our geothermal system. On the sticker it says minimum electrical requirement is 46.6a but the geothermal installer says we need at least 70a. The generator we're planning on using is a Champion 7500/9500 witha 50a recep. Here are the stickers on the geothermal unit:
Amps to run geothermal unit
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Your proposed generator is not even close. You could maybe, MAYBE get by with a 13kw generator, if you're not running any other loads, and you had a soft-start kit installed on the heat pump.
Inrush current on the heat pump is going to stop your proposed generator dead in its tracks. 7500W is just over 30A at 240V. 9500W is 40A. Inrush current on a heat pump can be in the 80 or 90A range...or higher. Hard to tell from the picture, is there a rating for LRA? (Locked Rotor Amps) that will be the maximum inrush current.
The generator you're planning on using is good for running lights and refrigerators and a few other devices. If you're careful, you might be able to run your water heater or dryer, but not at the same time.
Inrush current on the heat pump is going to stop your proposed generator dead in its tracks. 7500W is just over 30A at 240V. 9500W is 40A. Inrush current on a heat pump can be in the 80 or 90A range...or higher. Hard to tell from the picture, is there a rating for LRA? (Locked Rotor Amps) that will be the maximum inrush current.
The generator you're planning on using is good for running lights and refrigerators and a few other devices. If you're careful, you might be able to run your water heater or dryer, but not at the same time.
I can't tell exactly from the images (not enough resolution), but that is Waterfurnace with a desuperheater, yes? It probably has an IntellaStart (that's what WF calls it) on it (I have a Series 5 with a DSH and it is hard NOT to get that option).
Without the softstart, my 5-ton unit has a 104 LRA according to the label. With the softstart, it is still 37A. The Series 5 have two-stage compressors.
You still have to worry about the blower unit, the DSH unit, and the coolant pumps also. It is all on the labels (watch out for the pumps, I have two 240V pumps, you might have two or one - their label assumes a single pump).
The tech put a clamp-on meter on it after installation and the whole thing had about 18A at steady state if I remember correctly. It might have been in the low 20s however.
And if you have auxillary heat packs (I have 15Kw), the blower is powered from one of the heat pack circuits. You want the blower to work, but you really don't need/want the 5Kw/10Kw/15Kw heat packs trying to start. Disabling the aux heat depends on which t-stat you are using and the model.
I have three separate circuits going to the unit. 50A for the compressor. A 60A and a 30A for the set of heat packs (the 60A is for a pair of 5Kw and the blower, the 30A is for a third 5Kw). You can configure upto four for a total of 20Kw. If you don't any heat packs, the 50A also drives the blower of course.
The WF website has quite a bit of info you can download (actually too much if you aren't used to reading all their charts).
Without the softstart, my 5-ton unit has a 104 LRA according to the label. With the softstart, it is still 37A. The Series 5 have two-stage compressors.
You still have to worry about the blower unit, the DSH unit, and the coolant pumps also. It is all on the labels (watch out for the pumps, I have two 240V pumps, you might have two or one - their label assumes a single pump).
The tech put a clamp-on meter on it after installation and the whole thing had about 18A at steady state if I remember correctly. It might have been in the low 20s however.
And if you have auxillary heat packs (I have 15Kw), the blower is powered from one of the heat pack circuits. You want the blower to work, but you really don't need/want the 5Kw/10Kw/15Kw heat packs trying to start. Disabling the aux heat depends on which t-stat you are using and the model.
I have three separate circuits going to the unit. 50A for the compressor. A 60A and a 30A for the set of heat packs (the 60A is for a pair of 5Kw and the blower, the 30A is for a third 5Kw). You can configure upto four for a total of 20Kw. If you don't any heat packs, the 50A also drives the blower of course.
The WF website has quite a bit of info you can download (actually too much if you aren't used to reading all their charts).
I'm going to print that out and show it to my wife, just so she knows it's possible. :wink2:
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WAY too small!
Good thing I asked you guys! Thanks for all the advice so far
The unit we have is: American Standard A2GX064 5.0 ton 3 stage heat, 2 stage cooling with GeoStart and 20Kw backup electric heat (which I would manually disable if using a generator)
What if we one day get either Generac GP1500E (15k/22.5k) or Generac GP17500E (17.5k/26.25k)? Both have 50A receptacles, is it safe to re-wire it to have a 70A or other amperage receptacle to be able to plug into the interlock kit at the panel?
The unit we have is: American Standard A2GX064 5.0 ton 3 stage heat, 2 stage cooling with GeoStart and 20Kw backup electric heat (which I would manually disable if using a generator)
What if we one day get either Generac GP1500E (15k/22.5k) or Generac GP17500E (17.5k/26.25k)? Both have 50A receptacles, is it safe to re-wire it to have a 70A or other amperage receptacle to be able to plug into the interlock kit at the panel?
If you are going with a portable generator that big, you would be much better off getting a standby generator installed. A portable generator uses a lot of gasoline. My 7500/8500 watt burns about 8 gallons of gas in 10 hours at 50% load. With my oil fired hot water and oil fired boiler , lights, fridge, microwave and small appliances, tv, that is all my load is. Gasoline can be hard to get in an extended power failure. Something large enough either diesel, gasoline or portable propane tanks to handle your load is going to consume a lot of fuel.
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