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Couple Voltage Issues in Circuit...

1123 Views 8 Replies 3 Participants Last post by  biggles
Ok so we just bought a really old building, and part of it was recently finished as a one bedroom apartment.

Nearly every single wall is on its own circuit. Literally. And the place is max 500sq ft.

The bathroom and kitchen share a wall.

Two outlets one on bathroom side, one on kitchen side both pull 150 volts at the outlets (GFCI) then two more in the kitchen on a seperate wall (supposedly seperate circuit) only pull 89 volts.

Both walls being exactly 30 volts under and 30 volts over....

Also when one breaker is turned off the other circuit still pulls between 5-11 Volts, when both circuits are off they pull zero?

I discovered all of this trying to figure out why the GFI's werent working, but now ive got a whole new problem?

Also, the two outlets pulling 150 are closest to the breaker box, and before the other two 89 volt outlets if they do share some kind of line.

Im kind of at a loss as to why this would happen, and what to do to fix it?
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Yes I tested hot to neutral. Will test hot to ground tomorrow when im back at the building.

What is MWBC?

By chance if it is an open neutral what are the steps to tracking down the issue? I.E. something other than tearing the walls/ceiling off looking for junction boxes?
Mwbc = multi wire branch circuit. as in, they ran 12/3 bx. Easiest place to start is to check the panel. Find the cable that is giving you the problem and find the cooresponding neutral. You say its a commercial building? If yes, im assuming you have a drop ceiling. Pop some tiles up near that kitchen/bathroom wall and investigate for a splice box. Also, it might be located in the device box as well Kmost likely in the ceiling)
Yes its a commercial building, but it was built in 1907(so says the cornerstone) This little apartment was done off in the back of the building somewhat recently. No drop ceiling.

Device Box = Junction Box?
Also, check from neutral to ground....i bet you have 120volts (which you shouldnt). This would be a dead give away to an open neutral.
Doing that first thing in the morning.
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