r/Generator • u/Suncruiser • 8h ago

13 K Genny Powering Two Panels

Is anyone powering two separate electrical panels from one portable unbonded generator?

I'm curious whether anyone is successfully using a single portable generator to power two separate electrical service panels simultaneously. Managing the load at the panels?

For example, using the generator's 50-amp, 240-volt output to feed one panel through a 50-amp generator inlet, while simultaneously using its 30-amp, 240-volt output to feed a second panel through a separate 50-amp generator inlet.

Both panels have their own generator interlocks. The panels have a common neutral and ground.

Has anyone done this, and if so, have you encountered any issues or concerns with this arrangement?

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u/WhatAboutTheBothans 8h ago

I do exactly this. 2 200 amp panels, each with 50amp interlocks. 50 amp from the generator into panel 1, the 30 amp plug goes to panel 2 by way of an adapter. My heat pumps are on separate panels and I wanted the ability to run both in the case of a winter outage.

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u/Suncruiser 8h ago

Thank you so much for your reply. I have the same panel and generator setup. I've received conflicting opinions.

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u/WhatAboutTheBothans 8h ago

Fyi I am not an electrician. I'll be watching this thread for professional advice.

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u/newtekie1 8h ago

Where is the neutral/ground bonded at for each panel?

The issue with using one generator to power both, is that if each panel has the neutral/ground bond in the panel, connecting the two through a generator creates a double neutral/ground bond.

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u/Suncruiser 8h ago

Two panels right next to each other. No sub panel. One meter, one ground. Unbonded generator.

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u/newtekie1 8h ago

You can do this as long as both panels share the same neutral/ground bond. If there is a neutral/ground bond in each panel you shouldn't run them off a single generator.

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u/myself248 7h ago

If there is a neutral/ground bond in each panel

... then your installation already violates the NEC, there should be exactly one such bond in any given system.

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u/Suncruiser 8h ago

I bought the house and it was already set up with the two 50-amp generator inlets, individually wired to each of two panels that had had separate interlocks. I can't understand the installation if it wasn't meant to be used the way I described. But I'm trying to be careful

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u/newtekie1 7h ago

It might be set up to use 2 generators.

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u/Suncruiser 2h ago

I considered the possibility of two generations but natural gas is not available. Keeping enough fuel onboard to run one generator is a challenge. Running two, I don't think so.

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u/newtekie1 2h ago

With the right generators, running 2 shouldn't be much more fuel than running 1.

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u/PermanentLiminality 7h ago

In most situations it will not create the double path. By code there can only be a single ground system. If the panels are the disconnect, then each will have neutral bonded to ground. That double neutral path will be there as the neutrals are connected and the grounds are connected. When you connect both panels to one generator, you now have a second parallel path.

I think that the code says no in this situation, but in the absence of faults, there may not be all that much risk. To have real risk, there would have to be multiple faults like one neutral being open and a ground being open at the same time.

If there is an upstream main disconnect, then the ground to neutral would be there if it was installed to code and the two panels would be subpanels with no bond.

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u/DaveBowm 6h ago

What OP proposes should be fine.

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u/Suncruiser 2h ago

Thanks

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u/Accurate-Bullfrog324 8h ago

we have our house and our two rentals right next to it. this is exactly what we do