Generator size needed for WF Series 7

Discussion in 'General Discussions' started by Aaron H, Apr 18, 2020.

  1. Aaron H

    Aaron H New Member

    I have a 3 ton WF series 7 with Intellistart. I am looking to get a portable generator that can run the geo. The house has a 30 amp transfer switch. I borrowed a Westinghouse generator (7500 continuous, 9500 peak) and tried that out. It would try to start up the geo but before long I got an E8 error (voltage over/under shutdown). I didn't know if that is a result of the generator not producing clean enough power or being underpowered. Westinghouse is a generator brand I had not heard of before so I don't know the quality of that generator vs more familiar brands like Generac or Champion. I was wondering if people had any recommendations of generator brand and size to get. Thanks in advance for any advice!
  2. gsmith22

    gsmith22 Member

    minor point, but I don't think the WF series 7 has an "Intellistart" module option in the same way it is available for the 3 and the 5 series. My installer had quoted it for my 7 series installation and then didn't install an "intellistart" module prompting me to question it. He wasn't a fountain of information so I did some research and intellistart it isn't an available option for the 7 series. I don't know this for sure, but I suspect the 7 series naturally mimics having an intellistart module by starting in a low compressor stage (drawing less current) and ramping up slowly to the stage needed to satisfy the thermostat thereby not shocking the system with a huge current draw all at once. Maybe someone else can confirm.

    Anyway, I'm tuning into this thread too as I have a large portable generator and haven't tried to start one of the heat pumps with it but it would be nice to hear from others who have been successful. power loss in the depths of winter is my new nightmare.
  3. Aaron H

    Aaron H New Member

    That is interesting to hear about the Intellistart option. It was definitely on my quote for the WF series 7 so I just assumed it was installed. Hopefully someone can weigh in on that aspect as well.
  4. SShaw

    SShaw Member

    Intellistart is not an option on the 7 Series, presumably because it's unnecessary. From the 7 Series brochure: "Variable capacity compressors offer soft start capabilities and gently ramp up to speed for quiet operation while also eliminating light flicker."
  5. gsmith22

    gsmith22 Member

    guess no one is trying to start their WF 7 series with a large portable generator?
  6. Noobie

    Noobie New Member

    I wish I could answer the question directly, but can’t. I have two WF series 7 on battery backup (each battery 16 kWh; WFs are a 4 ton and a 5 ton). During outages, there were no problems with heat. Startup is very gentle.

    I also have a 8kw propane generator, but have not had to use it to charge the batteries (and don’t expect to).
  7. mrpac

    mrpac Member

    wOw. I would like to see a pick of the 16kWh Battery Set.

    How big are they? Do you say you have a generator installed to charge the Batteries? That sounds like an incredible system that you have.
  8. Noobie

    Noobie New Member

    They’re about 6’ tall, 2.5’ wide, maybe 1.5’ deep in their own dedicated closet. They’re made by Sonnen, a German company.

    Usually they’re solar charged, but since the previous owner installed a generator, I kept it in case the grid is down for prolonged time, there’s no sun, and the batteries are drained. It gets cold in MA, and I didn’t want to keep the oil burner as a backup.
  9. Noobie

    Noobie New Member

    Mrpac, the batteries are each approx 6’ by 1.5’ by 2.5’. They’re made by Sonnen, a German company.

    They are not (generally) charged by the propane generator, but instead by our solar field. I haven’t had the upgraded ground based solar field for long, but on a good day it generates about 225 kWh, way more than needed to charge the batteries. In MA, the utility net meters, so it’s all the same to me whether the excess goes to the batteries in my house or the “batteries” in the grid. In the summer we rack up credits, in the winter we deplete them. Geo and solar are a match made in heaven, and if your location has frequent outages, batteries are a welcome addition.

    I didn’t install the propane generator, but since it was there, I maintain it “just in case.”
  10. vortrex

    vortrex Member

    I also have a WF 7 series, 4 ton, and would like to know about using a portable generator.
  11. mrpac

    mrpac Member

    Without seeing the Nameplate starting current on the box, it is like stabbing in the dark. For the most part, portable generators will not provide backup for typical GEO heat pump setups.
    The largest portable generator that I have seen is a 12kW model, 10kW normal, but only 12K peak - and that is not continuous. A soft starter at minimum speed may be started with a portable genset, but may not provide the power needed throughout the full range requirement of the GEO system.
    I have read a few threads on this forum where people say they work, it really depends on your setup, both the genset and the size of the GEO system.

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