Running multiple wires thru the current clamps

#1

Hello there,

Little bit of an unusual setup: I have an outdoor panel with the connection form PG&E, where the meter is connected to the breaker box via bus bars, not cables (thus cannot put the current clamps around them). Can’t put the clamps before the meter, because that’s PG&E.s

The external panel feeds some devices like my well pump, EV charger, and outdoor power, and then there’s the feed into the house. I can put the current clamps onto the feed into the house, and the sense can detect those devices, but not the breakers on the outside panel. In looking at the picture, the breaker above the mains is the well. I think I might be able to route those wires along with the house mains thru the current clamps (so there would be the house gauge wire along with the 12 gauge ware thru each clamp.

Will that work ok in terms of being able to detect the well pump?

#2

Had somewhat the same situation - bus bars feeding the main panel. My electrician cracked open the PG&E meter side to clamp around the cables before the buses, then routed the clamp leads through a small opening between the sides, to the Sense on the breaker side of the dual box.

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#3

Hello there,

Interesting. My electrician was not enthused about doing that, as he indicated that you’d have to be careful not to short the meter out (unless you broke the PG&E tag), and PG&E would be very unhappy if they found it…

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#4

Most of the Techs have seen hundreds of Tags cut off. If you explain it to them they will most likely understand. Show them your Sense app and hell, he might want to buy one too. Their geeks too ya know. :sunglasses:

#5

Hello there,

Replying to myself; I did run the well pump wires thru the current clamps (along with the house mains) and it seems to work ok. Eventually sense recognized the well pump, so I can detect when it’s on/off

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#6

My electrician cut the PG&E tag, hooked the clamps on the meter side and ran through holes he drilled between the two boxes. Then he put the tag back and soldered the ends together :slight_smile:

#7

I think the only limit to the number of wires that can run through a CT is the size of the clamp. As long as all of the wires are on the same phase, it should measure total current the same as a single wire.

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#8

You can run multiple wires through the CT’s. You just need to be very careful about staying on the same leg, and the “flow” direction. If you run the extra wires backwards through the CT, they will subtract instead of add to the meaured current.

The best bet would be to do what was mentioned, open the meter base and put the clamps around the feeders. If you notified your power company beforehand that you were intending to cut the tag, they would probably greatly appreciate it. According to the meter servicewoman that came out to install my solar meter, if they encounter a cut tag apropos of nothing, they need to do an investigation for meter tampering.