voltage on neutrals

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Alaska
I have 103v on the neutral of a 120v circuit is. The voltage goes away when I wire nut several other neutrals together, (pig tails to other outlets of the same circuit). The transformer is 208v and the neutral is being shared with the 3 phases which form the 3 circuits. I have checked the Xo at the transformer, it is landed correctly. I checked the integrity of the 208v phasing to make sure that two legs were not on the same phase, all seems ok there also. I have not checked (yet) to see if a different neutral has been introduced into the circuit, as that little task will be intense. Any ideas? what did I miss? Thanks
 

Smart $

Esteemed Member
Location
Ohio
In addition to 'stiff's question, the next is are any of the three circuits energized that share this neutral?

Sounds like you split open a neutral splice of a multiwire branch circuit (MWBC). If you only deenergized one or two of the contributing circuits, the remaining live circuit(s) can easily put 120V on an open-path neutral wire, or worse... become a voltage divider for other connected loads, perhaps even causing them to let out the smoke contained internally.

Another possibility is if your MWBC is dead but run with other circuits in close proximity, such as in the same conduit. The other live circuits may cause phantom voltage (<search term) reading on an open-path conductor when measured with a high-impedance input type meter (such as a typical DMM).
 
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Location
Alaska
Yes 3 circuits , one neutral, I have seen this before with two of the circuits landed on the same phase that share a neutral, you don't get a true 120v but you get enough to get your attention, if you know what I mean. (phase lag) All 3 hots are landed on different phases. There are a trillion outlets on these 3 circuits, I hate chasing wire nuts. Was hoping you guys might know of a trick that I wasn't aware of.
 

mcclary's electrical

Senior Member
Location
VA
If you keep on opening the neutral of this MWBC,,,,you are going to FRY some things that are on these circuits!!. You can cook TV's,,,,MICROWAVES,,,,COMPUTERS,,,,,it can get expensive. NEVER OPEN this neutral when energazed. With that being said,,,,,,,,,seeing voltage on this OPEN neutral IS NORMAL!!.....As long as it goes away when terminated you're fine. Stop opening joints before you burn something up
 
Location
Alaska
Very true and thanks. What started all of this was a bad GFCI recept, the recept's neutral was hot (with the wire nut on) But you guys are right, when I pulled my head out and looked around, I knew better. So I'm going to consider the problem schooled (me) and the circuit fixed. Thanks
 

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
If you keep on opening the neutral of this MWBC,,,,you are going to FRY some things that are on these circuits!!. You can cook TV's,,,,MICROWAVES,,,,COMPUTERS,,,,,it can get expensive. NEVER OPEN this neutral when energazed. With that being said,,,,,,,,,seeing voltage on this OPEN neutral IS NORMAL!!.....As long as it goes away when terminated you're fine. Stop opening joints before you burn something up

If a microwave is used for cooking, how do you cook a microwave? maybe like a T.V. Picture in picture (PIP) microwave in microwave (MIM)??? :confused: :wink:
 
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