Ganged Neutrals

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dmga

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Philadelphia
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Electrician
Hello All,

Just for my edification: I came upon a job this morning that made me wonder about code. The residence has a Siemens lighting panel that is a bank of relays controlled by a CPU. All of the lighting circuits run to the relays in the panel as well as the feeds from the main panel. The relays are then controlled by low voltage switches throughout the house.

All of the neutrals coming into the panel are tied into a single busbar, all of the grounds on one bus as well. The two are not bonded together. I don't see anything wrong with it electrically and was curious if there was anything in the code about this. My work had nothing to do with the panel, so this is just a point of interest to me. Always curious.
 
If I understand you correctly this is a violation. There must not be any GFCIs or AFCIs supplying these circuits as they would trip.
But maybe I'm not clear in your description. Does this panel have the branch circuit breakers in it and is fed by a feeder? That would be another story.
 
The ones I have seen are not a panel. All the branch circuit are run to the individual relays and the low voltage sw controls the relay. The neutrals should only be connected to the circuit neutral that is common with the power conductor.
 
ptonsparky said:
That was common enough years ago.
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If there's only one branch circuit in the lighting panel, then it's obviously fine.

With more than one branch circuit, it was allowed until the 2011 NEC added 200.4 (now 200.4(A)). But the neutral bar would have to be supplied by a single large neutral, otherwise it would be a violation of 310.10(H) to have multiple neutrals smaller than 1/0 in parallel from the panelboard busbar to the lighting panel busbar.

Cheers, Wayne
 
wwhitney said:
If there's only one branch circuit in the lighting panel, then it's obviously fine.

With more than one branch circuit, it was allowed until the 2011 NEC added 200.4 (now 200.4(A)). But the neutral bar would have to be supplied by a single large neutral, otherwise it would be a violation of 310.10(H) to have multiple neutrals smaller than 1/0 in parallel from the panelboard busbar to the lighting panel busbar.

Cheers, Wayne
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Right, one large neutral.
 
texie said:
If I understand you correctly this is a violation. There must not be any GFCIs or AFCIs supplying these circuits as they would trip.
But maybe I'm not clear in your description. Does this panel have the branch circuit breakers in it and is fed by a feeder? That would be another story.
Click to expand...
There are no GFCI or AFCI in this panel, just lighting.
 
wwhitney said:
If there's only one branch circuit in the lighting panel, then it's obviously fine.

With more than one branch circuit, it was allowed until the 2011 NEC added 200.4 (now 200.4(A)). But the neutral bar would have to be supplied by a single large neutral, otherwise it would be a violation of 310.10(H) to have multiple neutrals smaller than 1/0 in parallel from the panelboard busbar to the lighting panel busbar.

Cheers, Wayne
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Thanks for all of your input.

I went back and checked, multiple neutrals back to the main panel. The Siemens control and the main panel are next to one another. If I am understanding correctly, this could be brought into compliance by running a 1/0 neutral from the main neutral bus to the neutral bus in the Siemens panel. Would all of the smaller neutrals from the main panel need to be removed?
 
I worked on quite a few houses in the 90s that had Vanguard lighting, Lutron Lumaster, et al.

I don't believe I ever worked on anything from Siemens, but it sounds like some stuff I did work on.
 
dmga said:
Thanks for all of your input.

I went back and checked, multiple neutrals back to the main panel. The Siemens control and the main panel are next to one another. If I am understanding correctly, this could be brought into compliance by running a 1/0 neutral from the main neutral bus to the neutral bus in the Siemens panel. Would all of the smaller neutrals from the main panel need to be removed?
Click to expand...


No, make a bunch of connections. Each branch circuit neutral needs to connect to the same branch circuit load.

200.4 Neutral Conductors. Neutral conductors shall be installed
in accordance with 200.4(A) and (B).
(A) Installation. Neutral conductors shall not be used for
more than one branch circuit, for more than one multiwire
branch circuit, or for more than one set of ungrounded feeder
conductors unless specifically permitted elsewhere in this Code.
Click to expand...
 
dmga said:
Thanks for all of your input.

I went back and checked, multiple neutrals back to the main panel. The Siemens control and the main panel are next to one another. If I am understanding correctly, this could be brought into compliance by running a 1/0 neutral from the main neutral bus to the neutral bus in the Siemens panel. Would all of the smaller neutrals from the main panel need to be removed?
Click to expand...
If it's a conduit, yes. If it's wired in Romex, you can't do that because all the circuit conductors have to be in the same cable 300.3(b)
 
Dennis Alwon said:
No, make a bunch of connections. Each branch circuit neutral needs to connect to the same branch circuit load.
Click to expand...

Thanks Dennis,

I will inform the homeowner that there is a violation and let them know the work to bring it into compliance is not earth shattering.
 
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