# Questions on a Neutral



## RIVETER (Sep 26, 2009)

*Neutrals*



dplayboi said:


> Can you connect neutrals from different circuit together in a box....even though they are tied together in the panel. Why or Why not?


If there is more than one phase conductor and they are of the opposite phase their common neutrals can be tied together. If there is a situation of multiple phase conductors ,and there may be a chance of some being the SAME phase, the neutrals have to be kept separate so that the neutral will not overheat if both, or possibly more circuits are run at or near their max. Is that what you are asking?


----------



## kbsparky (Sep 20, 2007)

With modern circuits requiring separated neutrals, like AFI's for example, I would keep `em separated.

Tie in all your grounds together, but leave the neutrals separated.

-KB


----------



## 480sparky (Sep 20, 2007)

Tying all the noodles from the panel out to a box most likely will violate 310.4 as well.


----------



## dplayboi (Feb 12, 2010)

multiple phases opposite phases...same thing right? i mean you said if more than one conductor with opp phases; you could tap the neutrals from different phases together but than you said multiple phases don't tap the neutral...CONFUSED!!! I mean just think about a 3 gang box with three switches controlling three different light circuits. one neutral circuit contains netural for light and recepts(so will you tie those together) and the other two switches have their own neutral.

My grandma flood lights blew out the bulbs in 4months...how could that be? i open up the switch box and all the neutrals were tied together (total of 11 whites; two for switch 1 two for switch 2 and 1 for recept 6 for flood light switch) i think the neutral had something to do with it


----------



## RIVETER (Sep 26, 2009)

*Neutral*



kbsparky said:


> With modern circuits requiring separated neutrals, like AFI's for example, I would keep `em separated.
> 
> Tie in all your grounds together, but leave the neutrals separated.
> 
> -KB


You are most likely correct. I have never installed AFCs.If they have a comparator circuit as a GFCI does I can see why the separation. Does the breaker have to have the designated neutral, so to speak, to monitor the characteristic current of the ARC?


----------



## 480sparky (Sep 20, 2007)

RIVETER said:


> You are most likely correct. I have never installed AFCs.If they have a comparator circuit as a GFCI does I can see why the separation. Does the breaker have to have the designated neutral, so to speak, to monitor the characteristic current of the ARC?


 
AFCI breakers provide a certain amount of GFCI protection (but not enough to qualify as personel protection), so combining two AFCIs on a MWBC would produce an imbalance tripping one or both of the breakers.

Same thing happens when you try to put two GFCI breakers on a MWBC.


----------



## Dennis Alwon (May 9, 2009)

dplayboi said:


> multiple phases opposite phases...same thing right? i mean you said if more than one conductor with opp phases; you could tap the neutrals from different phases together but than you said multiple phases don't tap the neutral...CONFUSED!!! I mean just think about a 3 gang box with three switches controlling three different light circuits. one neutral circuit contains netural for light and recepts(so will you tie those together) and the other two switches have their own neutral.
> 
> My grandma flood lights blew out the bulbs in 4months...how could that be? i open up the switch box and all the neutrals were tied together (total of 11 whites; two for switch 1 two for switch 2 and 1 for recept 6 for flood light switch) i think the neutral had something to do with it


I believe you have terminology problems. The white wires tied together in the switch box may be all from the same circuit (circuit breaker). If that is the case then you must tie them together. Now if you have 2 or three different circuits - coming from different circuit breakers-- then you must separate the neutrals. If you don't it is a violation and will cause unwanted electromagnetic fields in the house.

If a flood light is lasting 4 months and it is on often that is pretty good.


----------



## JackBoot (Feb 14, 2010)

To add onto what Dennis said, when someone mentioned that you could tie the neutrals together from opposite phases, they were talking about a MWBC in which the neutral is shared.


----------



## bdeots (Feb 10, 2010)

Did you have the weather washers on the Floods. They are a washer made of a non combustable material that keep ice and water from forming at the base of the fixture. they go on the shell of the lamp. These will dramaticaly increase the life of the lamp. Also check the wattage. A high wattage lamp creates a lot of heat. Heat and dampness dont mix well. Try to keep the wattage at 100. Also install a 130v rated lamp instead of a 120v. Big difference also. :thumbsup:


----------



## Toronto Sparky (Apr 12, 2009)

I always thought that one could only share a neutral when used for split receptacle , drier, or stove in residential.


----------

