I’ve got a (for me) confusing output from trying to measure heat strips. The strips are on a 20A dual breaker. I can see 3 cables with 2 black and one white. I initially didn’t see neutral so assumed I could use one 50A C clamp on either leg. The output (~3400 watts) is higher than the total power from the mains (~2250 watts). Knowing I did something wrong I could see that there was a neutral so I placed a 50A c Clamp on the second black wire (in opposite orientation from the first). But now both c Clamps are measuring within 10watts of each other and both are still ~3400 watts. Appreciate any thought on what I’m doing wrong.
It would be unusual for a 240V circuit to use two black and a red wire. Maybe if it’s running completely in conduit, but 12/3 wire is black, red and white. So, I think there is more to this. Are you sure there is only one neutral wire?
Could you post a picture of the breaker? How is it labelled? Are these heat strips baseboard type units or inside an air-handler?
I’m assuming you have double checked on these CTs. Please show your inputs setup screen, and a screenshot of your status display with the strips on.
What do you get if you move that extra CT to the neutral wire?
It’s the bottom double breaker (20A). They are heat strips for gutters. There are 2 black wires and then a white wire behind into the breaker.
Still not sure if it’s a 240V load or two 120V loads. The white wire looks to be from the breaker to the neutral bus, which would be just for the GFI function. The question is what is going to the strips? It would be unusual to run 240 over two black wires, and hard to find a cable with two black wires in it. But they do seem to be a matched set based ion the two CT readings.
Your basic problem is that you have all of the CTs configured as 200A CTs. The CTs on the wires in question appear to be 50A CTs. So your readings are 4x the correct value. Try changing the model to what is printed on the CT and the power should come down to about 825 Watts each. You can probably just use one CT and either check double in the setup, or it looks like you have enough wire to pass both conductors through the one CT in opposite directions.
I think it’s 2 separate 120V loads. Sorry for the stupidity on the CTs. All is good now I think.
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