Greeting gentlemen: Had a panel energy monitoring tool installed, all working well, am considering adding to it slightly. But I think the help desk support guy is mildly inaccurate in what's he's telling me, and thus the requests I make of the electrician.
Question 1: Is there any way for a 240V branch circuit with no neutral to be unbalanced (I'm thinking no)? Aside from something installed incorrectly and using ground as a neutral (unlikely, house built in '04, electricians all union and seemingly well trained).
Why do I ask? I've been told I need a CT on each 240v leg for accuracy, yet the tool allows a CT valued to automatically be doubled. I could give a **** about the cost of a few CT's, but the panel looks like a rat's nest w/all the CT's in there and I'd limit the sheer number of them by only using 1 per 240V's if physics say must they be balanced.
Cases in point:
A: I read the manual on a Tesla Wall Charger: I know it's on two legs and a ground, and the tool consistently reports those legs to be within .3% of each other. Well within the margin of error for a CT. If I'm correct above that's a perfect time to use 1 CT and allow the load to be 2X.
B: My Geothermal furnace has (2) 60 amp 240V circuits with no neutral. One is showing a 4% usage difference. As above, I'd believed that to be impossible. So:
Question 2: Am I wrong and this is an early indicator or trouble? Or is this a set of CT's that are poorly matched (or one flawed, or...)?
I suppose it all comes down to question 1, for if as I assume they must match then all that's left is CT error, and to some degree that's expected.
Thanks for any learnings you can share!
-d
Question 1: Is there any way for a 240V branch circuit with no neutral to be unbalanced (I'm thinking no)? Aside from something installed incorrectly and using ground as a neutral (unlikely, house built in '04, electricians all union and seemingly well trained).
Why do I ask? I've been told I need a CT on each 240v leg for accuracy, yet the tool allows a CT valued to automatically be doubled. I could give a **** about the cost of a few CT's, but the panel looks like a rat's nest w/all the CT's in there and I'd limit the sheer number of them by only using 1 per 240V's if physics say must they be balanced.
Cases in point:
A: I read the manual on a Tesla Wall Charger: I know it's on two legs and a ground, and the tool consistently reports those legs to be within .3% of each other. Well within the margin of error for a CT. If I'm correct above that's a perfect time to use 1 CT and allow the load to be 2X.
B: My Geothermal furnace has (2) 60 amp 240V circuits with no neutral. One is showing a 4% usage difference. As above, I'd believed that to be impossible. So:
Question 2: Am I wrong and this is an early indicator or trouble? Or is this a set of CT's that are poorly matched (or one flawed, or...)?
I suppose it all comes down to question 1, for if as I assume they must match then all that's left is CT error, and to some degree that's expected.
Thanks for any learnings you can share!
-d
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