Easy way to safely access backup power for home and free (for some PG&E customers)

[tls]

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Is there a safety issue? The truck circuitry is still protected by its built in GFIC and the house is presumably protected by its own circuitry. The truck maintains its own ground as does the house. Is an ungrounded cable an issue when both ends have their own (though different) grounds? Hmmmm.​

The truck end doesn't have a ground, really. The tires are very good insulators. But the truck end has a GFCI, which I suppose would trip if you shorted line to ground through your body while plugging in the cable - because the line and neutral current would be unbalanced, and that's how GFCI's work.

That suggests to me that code to the contrary notwithstanding, a cable like this that simply does not connect ground between the truck and the house is a safe way to work around the issue with transfer switches and bonded neutral, in general. It's just that you - or the electrician who installs a transfer switch or generator inlet for you "behind the meter" - are subject to code and so you are not supposed to do this; but on the utility's side of the demarcation point, NEC does not apply, so they can let you do it there!

There are people here who know a lot more about this than I do. Does the above seem right?

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[Maquis]

But the truck end has a GFCI, which I suppose would trip if you shorted line to ground through your body while plugging in the cable

I don’t think anybody in their right mind would switch on ProPower before connecting the cable at both ends.

 

[GDN]

Simple steps I wrote up and added to my electrical panel documentation - adopt as necessary.

 

[dmd3home]

Of course the truck doesn't have a "ground" ground....if you know what I mean, but I assume the truck frame is a ground for for the pro power electrical circuitry on the truck (and the 12v too, I guess).
As for the GFI protection, I'm not a "professional", but yes, with 120v circuitry it is looking for any difference between the hot and neutral current flow....showing that some current flow is "lost" somewhere. But with 220v it must be looking at L1 and L2 detecting any difference in current flow between these two hot legs (no neutral involved). A ground wouldn't even necessarily enter in on either GFI circuitry (though there will always be a connected available ground as with any proper electrical circuit). The "generator" cord supplied by PG&E is 220V only.

Again, I'm just very pleased it works!!!!

 

[Maquis]

Of course the truck doesn't have a "ground" ground....if you know what I mean, but I assume the truck frame is a ground for for the pro power electrical circuitry on the truck (and the 12v too, I guess).
As for the GFI protection, I'm not a "professional", but yes, with 120v circuitry it is looking for any difference between the hot and neutral current flow....showing that some current flow is "lost" somewhere. But with 220v it must be looking at L1 and L2 detecting any difference in current flow between these two hot legs (no neutral involved). A ground wouldn't even necessarily enter in on either GFI circuitry (though there will always be a connected available ground as with any proper electrical circuit). The "generator" cord supplied by PG&E is 220V only.

Again, I'm just very pleased it works!!!!

On a 240V, 3 wire circuit, GFCI protection monitors all 3 conductors (L1, N, L2). If the vector sum of all 3 is more than 6mA, it must trip. If the sum is 3mA or less, it cannot trip.

If the cord was “220 only”, you would not be able to properly power 120V loads in your home.

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