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Trying to use ProPower with Transfer Switch

v2h8484

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I'm not that familiar with an autotransformer, but from what I see, it has a direct electrical connection between the the primary coil (the truck) and the secondary (the load...house circuit etc.). I don't see how this would eliminate the ground fault due to the bonded neutral at the main panel. Wouldn't the truck's GFIC still see that ground and trip?
No, the truck's neutral won't be connected which is used by the F150 Pro Power for GF detection. Instead the autotransformer will form a separate neutral for the loads. You can learn more here (https://en.wikipedia.org/wiki/Autotransformer).

But, I'm just theorizing here...I'm trying to find someone who has actually done this....or used an autotransformer with success....or an even better method. Which works the best? Please share.
Yes, I have used the autotransformer solution with the F150 Pro Power and it works fine. I'll try to make a short video when I get some time.
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dmd3home

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Yeah, I see, looks like it should work. I still like the idea of using an isolation transformer as there is no common electrical connection between the truck and the load. But with no neutral connection, the autotransformer should work. But, have you tried this? Has anyone tried it in this application? I'd like to find out how it works in practice, not just in theory...either using an isolation transformer or an autotransformer. Let's figure this out! Thanks.
 

ridgebackpilot

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Following and interested in the answers here. Using the Lightning to power, my house is made more complicated by the fact that I have both a solar array and Tesla Powerwall backup batteries.

I would only need power from the truck in case of a prolonged grid outage. I’m willing to install a transfer switch and the appropriate transformer, but see no reason to spend thousands of dollars on a solution I would use only very occasionally.

After all, I’ve already spent a bundle on the solar array and the backup batteries. Still, I do enjoy charging the truck, and my other EVs using only solar energy!
 

EVpower

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I have been using my 23 Lightning ER for home power back up since taking delivery this July. I found Ford’s Home Integration System did not seem like a good fit with our existing solar and generator system. I opted to use the 120/240-volt 7.2 kW Pro Power as a source in addition to my ICE generators.

Although we have 400 Amp electrical service, the average power consumption is a few kW when the air conditioning, dual electric oven or irrigation pump system is not needed. The Lightning has worked very well for utility back up for the two outage we experienced so far.

I opted to use an isolation transformer between the Lightning and the transfer switch for two reasons. I wanted to keep the truck ground fault and safety grounding in place I also wanted to use a transformer so only the 240-volt output from the Lightning or my 3-kW generator would be used. In past power outages, I have found that the 120-volt line to neutral loads I wanted to power at the time would trip the generator circuit breaker even though the total load was below the generators working rating. The transformer handles the imbalance, so the truck only sees equal current on each hot side of the inverter output. This may not be needed in every instance.

Used transformers can be found with some looking. New or used be sure to confirm either winding can be used for the source. Not all are designed to limit the inrush current when the input and output are used in the opposite of the designed flow.

Another post had asked about how the Pro Power waveform looked. When I checked with an oscilloscope, it was a good-looking sine wave. My calibrated eye put the THD at less than 1% on the bed outlets.



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dmd3home

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Steve....excellent! This is exactly what I'd hoped to do. There was added discussion here about using an autotransformer vs an isolation transformer. I thought the iso xfrmr a better choice (though a little more expensive). Do you have more specifics on the iso xfrmr you used and where you got it? Thanks much.
 

dmd3home

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Here's another related question I'm trying to find an answer for:
OK, if I'm using an iso xfmr from the truck to power the main panel, will my existing solar still be able to contribute? I'm assuming my solar is coming in at a slightly higher voltage and will dominate the power needs but also being supplemented as necessary with the truck. But, what if the solar alone is more than enough to power the existing loads? Will it then try to backfeed into the truck through the Pro Power? What would the truck do? Does it need some kind of blocking circuitry to ensure one way power? I'm guessing the ProPower inverter has something like that built in already but I'm hoping someone knows for sure. Anyone done something like this? Thanks
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