Shelley 3EM in US Svc Panel

Hi All,

My Shelley 3EM with three 120A CT clamps came in the mail. So excited, I pulled the face plate off my 200A main service panel and discovered the the two pole, 200A breaker is fed by what appears to be four conductors, two for each of 110V phases. The utility side of my meter, covered in threatening PG&E (California) seals, must split these phases from two conductors to four before it reaches my main load center. Frak! The CT clamps need to either trespass into the PG&E part of my box or I need to put them outdoors on the power line side of the weathers (yeah right! lol).

Anyone else get tripped up by this? What did you do?



I know your not going to like my suggestion. But do they (PG&E) have control to shut down things like A/C, Pool/Spa, during high demand? If so, you’ll need an electrician and maybe PG&E to sort that service panel. It may even mean you need to get a different monitoring module(s).
Before purchase, I would of opened the panel and investigated a lot before ordering. It is what I did, I went with the Shelly EM2 for my panel after inspecting how it was setup.

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Hi lordwizzard,

PG&E does not have any “demand response” control to shed any of my loads, which currently are quite modest as I have yet to convert my hot water heater, oven/cooktop and home heating from gas to electric. This is a new 200A (44 KW) panel that just passed inspection with PG&E, so they consider it “sorted” AFAIK.

Thanks for your feedback!


So they use parallel conductors to deliver power? Unusual, but hey!
In that case, can’t you just monitor one of each of the parallel wires (one red and one black) and just multiply the result by two within HA?

I wouldn’t! You can have different amounts of current therefore different amounts of power (KWH) being delivered on each wire. That is why I said it was most likely beyond a normal owners knowledge at this point. I would get the panel model and check with a electrician or electrical supply to find out how things are internally with that panel. Ask questions and tell them what you want to do. “I want to monitor the power coming into the house via the mains in this panel. Why are there 4 mains and not 2?”
Then you can make a decision on the EMs that are needed.

Hence my surprise when I saw the breaker plate which implies that it’s a paralleling component.