YA newbie looking to purchase

Greetings, I’m in the U.S., and I have 2 panels (pictures below) that are each served by 200A. The left panel has most of the big appliances/HVAC and is therefore mostly 240V circuits. The right panel is the small stuff and is therefore just 120V circuits.

Based on reading the documentation and the community, I think this is what I need. Figured I’d just start with one unit and focus on the big appliances in the left panel. When I have that working, I’ll expand to the rest. Anyway, here’s my shopping list for CTs–I’d appreciate it if you fine folks would look over my shoulder before I hit the “purchase” button:

Does this look right?

Also a few questions:

  1. Can 2x60A be monitored by a 100A CT, or do I need to go up to the next level?
  2. My two main breakers (200A) are on the outside wall by the meter. I’ve never seen this before (new transplant to the area). In the midwest where I grew up, the main breaker is always in the panel. Does this matter or can I just put the whole-panel CT around the incoming main at the top?
  3. I love what others have done with orbit boxes, but my electrical panels are flush mounted in my laundry room. Ick. Trying to find a flush mount option for the iottawatt. Anybody done this?


Both Panels:

Left Panel Only:

It can.

You can monitor the mains with 200A CTs on the two incoming mains in each panel (total 4).

It’s a project. There are a few here in the forum. Plastic “media” boxes come in various sizes.

All of the “240V Pure” (two-wire) circuits can use a single 50A CT.

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Even 2x 50A or 2x 60A? Wow.

Crazy idea or clever idea? I was trying to figure out the best location for a recessed media box for a couple iotawatts when I noticed that each of my electrical panels has an unused 1” conduit straight down to the crawl space below. My crawl space is spacious, dry, pretty clean, and easy to run electricity. I’d estimate the conduit is 6 feet long.

Question: any reason not to install the iotawatts in the crawl space? Are the CT cables long enough, and, if not, can I extend them somehow?


CT leads are 1.5m. See this post

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If my electrical panel has enough room, is there any reason the main iotawatt unit HAS to be located in a separate panel or project box?

It doesn’t need to be in a separate panel, but there are a couple of reasons why it should not be placed in the breaker panel:

First, it’s not approved to be mounted inside a panel, so it would be a code violation. Only the CTs are approved to be inside the panel.

Second, the WiFi usually doesn’t work through the metal box.

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What happens if the wire gauge doesn’t fit? Are there larger hole 50A CTs, or do you go up to 100A?

EDIT: Also, re: 240V/120V circuits (which I’ve wired using the U-shape configuration as recommended), the documentation says that “a 50A CT can probably be used up to about a 2x30A breaker.” Does it follow then that, for my Cooktop and Oven, both of which are 2x50A (see grid in post #1), that 100A CT’s are warranted?

@overeasy any thoughts on the two questions in the prior post?

I don’t carry large4 hole 50A CTs. Yes you can use 100.


Thanks @overeasy. As a follow-up, what if the 240V/120V circuit were 2x 60A?
or 2x 100A?

I’m guessing 100A CT is enough for the former, but a 200A CT is warranted for the latter. Correct?

That should work ok.

Thanks. You mention in the instructions that “(a)n alternate method (to the U-shape config for 240V/120V circuits), and recommended with high amperage sub-panel circuits, is to put a separate CT on each leg.”

Does this instruction really only relate to sub-panels, or high-amperage circuits in general?

What’s the general analysis on one larger CT for a 240V/120V circuit versus two smaller CTs each on one leg? Does it matter? Are there plusses and minuses each way?

The reason is that higher Amperage means thicker wire and harder to manipulate into reverse, increasing the chance of breaking the circuit breaker or other disruptions. If your wires comply, by all means use the method. There is no downside.

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