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In preparation for a grid tied PV solar installation, we noticed that we have two breaker panels 100A ea fed by one meter. See picture.

In the past the house was two units two meters, but it was rehab to a single unit and the two 100A panels were not upgraded to one 200A but connected to one meter.

The meter box was locked by the utility company, I assume this passed inspection, but, Is it legal?

I fear that the inspection of the solar installation may not pass this time.

This is the closes answer I've found: two load centers on one meter

thanks for your time

To services to one meter

Edit:

I am attaching a picture of the meter socket box.

enter image description here

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  • Can you get us make/model information on your meter socket, as well as who your utility is? – ThreePhaseEel Aug 5 '20 at 0:11
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    I could not find the model, Make is Milbank (very likely L572-XLKK, no sure), utility is Comed – bobosam Aug 6 '20 at 2:20
  • Can you get us a photo of the label on the inside left of the meter base then please? – ThreePhaseEel Aug 6 '20 at 2:31
  • Also, can you step back and get us a photo of the overall setup? This may need a bit of rework... – ThreePhaseEel Aug 6 '20 at 2:42
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    Thanks for your help. I decided to enable a second meter, and have each meter with one electric panel. The utility company has a program "Net Metering Aggregation" which merges 2 meters in one account. – bobosam Aug 15 '20 at 18:16
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Your problem isn't only "two load centers on one meter", its "two wires in one lug that's not tested for such use"

While having multiple service panels fed in parallel from a single meter is fine, the devil is in the details, and that's where your current setup fails. Atop the fact that this is a dual 100A meter base to begin with, which means you're overloading the currently in-service meter socket, the definite issue with inspection is that right now, you have two wires connected to the same lug in a way that the lug was never intended for, which is a violation of NEC 110.14(A).

Considering the issue, I would have the existing base changed out for a single 200A meter socket with suitable tap lugs (a Milbank 200A base with a set of Milbank K5022-INT lugs would do the job) or a 200A meter-loadcenter with 2 100A branch breakers in it.

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I can't imagine why it wouldn't be - I have "double that" and it's bog-standard (Class 320 [400A, since 400A times 80% for continuous is 320A, and that's how meters are rated] meter feeding 2 200A panels.)

It's not functionally different from two meters feeding 2 panels if the power company is happy with the size of their wire to it, and I doubt there were two separate drop wires to the two meters before.

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  • This may or may not be overloading the meter socket jaws if this is all being pulled through one meter... – ThreePhaseEel Aug 5 '20 at 0:10
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    I sincerely doubt the PoCo would have sealed it in that case. – Ecnerwal Aug 5 '20 at 1:10
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    I could easily see where a lineman-in-a-hurry could make that mistake... – ThreePhaseEel Aug 5 '20 at 1:11

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