Neutrals in parallel

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domnic

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Electrical Contractor
Can someone please give me a example of parallel neutrals causing a problem or any type of danger ????????????????????????????????????????????????????
 
Can someone please give me a example of parallel neutrals causing a problem or any type of danger ????????????????????????????????????????????????????
J box 2 circuits or more and tied all neutrals together, you will have parallel neutrals back to panel. Seen many times. Issue that all neutrals will be energized when only one circuit turned off. Lights are off but you will still have current potential on the neutral.
 
J box 2 circuits or more and tied all neutrals together, you will have parallel neutrals back to panel. Seen many times. Issue that all neutrals will be energized when only one circuit turned off. Lights are off but you will still have current potential on the neutral.

Yes, but that is an illegal hookup. One problem with parallel neutrals is if the installation did not follow code and one conductor was longer than another.

@domnic Are you talking about larger conductors like 1/0 and larger?
 
Yes, but that is an illegal hookup. One problem with parallel neutrals is if the installation did not follow code and one conductor was longer than another.

@domnic Are you talking about larger conductors like 1/0 and larger?
Illegal but extremally common in an area that doesn't have license requirements, that GC and handymen do their own thing and have never opened a code book, no permits and no inspections.
 
Not sure but I think he is wondering about ground (neutral) loops, EMF issues.
 
Not sure but I think he is wondering about ground (neutral) loops, EMF issues.
If i have a # 3 thhn and a # 6 thhn neutral from the meter base to the 100 amp panel . other than double lugging , what is the problem ?
 
If i have a # 3 thhn and a # 6 thhn neutral from the meter base to the 100 amp panel . other than double lugging , what is the problem ?
Where is the double lugging. You have a neutral (#6) and 2 hots (#3)---Is that correct? You really need to explain further. You are giving little bits of info but not enough to know what you mean. You cannot parallel wires smaller than 1/0 so I am not sure where the title fits here.
 
I think he means he has both a #3 & #6 going to the meter base neutral lug. Double lugged. Two in a hole.

The world will come to an end tomorrow at 6:23 AM

It's not supposed to be done. Someone didn't know better most likely.
WHY ????????????????????????????????????????????????
 
If i have a # 3 thhn and a # 6 thhn neutral from the meter base to the 100 amp panel . other than double lugging , what is the problem ?
Are both neutrals? If yes, the problem is a difference in resistance between the 2 different conductors forcing a larger load onto one of the conductors creating an imbalance, and potentially overloading one conductor. Also a code violation Each conductor of the parallel must be capable of carrying the full imbalance load imposed.
Review 310.10(G)(1)(2)

Wire sizes given and in combo with 100A OCD sounds as if you got 1 neutral 1 EGC not 2 Neutrals. That is not parallel unless you are N/G bonded at both ends. Then you have another code violation.
 
Parallel neutrals at the service two different sizes what harm or danger could it cause ?
 
The code does not allow wires smaller than 1/0 to be paralleled.

More than 1 wire in a lug designed for 2 wires.

Can't use THHN into an outdoor meter, needs to be THWN or XHHW etc
YOU are side stepping the Queston !!
 
If you have 2 different sizes the damage could be that one conductor will carry most of the load and possibly overload. When the conductors are that short it may not be an issue anyway since the neutral load is usually much less than the phase loads.

Why is it illegal to use sizes under 1/0? I don't know... I assume because those size wires are usually available so no need to parallel a 100 amp load when a #3 or #2 can handle it.
 
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