Shelly EM doesn't work for most US breaker boxes

I bought a Shelly EM thinking I would use it to monitor energy usage from my panel. Unfortunately, this seems to be designed for European power panels and was impossible to integrate into my standard US breaker box (I do all of my own electrical work so am well versed in this sort of thing). If you are in the US I suggest not wasting your money here and just finding another way. I have a smart meter so am going to just integrate that. It also looks like and Square D have solutions that are designed to work better in the US if you don’t have a smart meter.

Because the diameter of the CT clamps are just a bit too small for a single leg of a 2-phase service or some other reason?

I’m using 4 EMs to monitor 8 individual circuits as I already have a solution for whole panel consumption, but I think it would be a very tight fit to snap a 120A Shelly CT around a leg of my 2-phase 200A service.

Yeah, giving a reason would be more useful than “it doesnt work so don’t buy it”.

Especially as someone recently posted a HOWTO for Shelly EM for US meter boxes.

Shelly EM works just fine for US panels. You do need two clamps to read both hot legs, but that’s to be expected. I have no complaints.

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Here is the thread

Yes - it turns out that many US boxes have 4 primary conductors in two phases. These tend to come in on large gauge wire that is difficult to access and tough to snap a small Shelly sensor around. If you are lucky and you find a single feed for your breaker box then you should be able to get it to work but new boxes (at least where I live) don’t have any easy single conductor that brings everything into the box you can monitor. I also realized after getting the Shelly that monitoring my meter is just as easy and much cleaner.

iotawatt will handle 4 conductors.

2 shelly ems will handle 4 conductors.

Bagging a product with no good reason and no explanation is, IMHO, bad form.

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I should add that the post above is also accurate - whether you have 2 or 4 conductors coming in depends upon how much power your house needs. Many houses will have 4. To figure this out you need to get into your breaker box which I don’t recommend. Most electricians are also not going to know the Shelly EM which is why its probably much easier to just monitor your Smart Meter if you have one. If you don’t and you aren’t and electrician then I would contact an electrician and find out whether they have installed monitoring systems before. It also seems there are APIs at many utilities that you can use to get a feed though seems less well developed.

In my new box those 4 conductors are situated behind the panel and very difficult to safely access and nearly impossible (impossible for me) to get into to snap a sensor around. In mine they are too close together for the clamp and its dangerous to access them because they are situated behind other wires. I am not bagging it for no reason - it just turned out to be a much more complicated solution than I expected which, in the case of my newer panel, wouldn’t physically work.

Thank you for explaining. Lucky that you are able to access your smart meter!