contactors and multiwire circuits

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aelectricalman

aelectricalman

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I am Planning to hang about 150 -6 lamp T5 4ft fixtures. Each fixture was originally to be wired where half feeds from panel S and half feeds from panel N. The circuits were getting wired back to contactors to be controlled independently. Well, the fixture came with a shared neutral rather than the specd 2-neutral set up in the fixture whips. Due to time we want to move forward placing the whole fixture in panel S (there is enough room) The set up proposed, so that we may keep the same configuration (at least similar), is to allow the first contactor to close, turning on the (low light setting) of three lamps and then when the customer wants full fixture lighting he can close the second contactor. Remember shared neutral. Has anyone used a similar configuration of contactors or is there a better idea for this application? I assume we cant 100% independantly operate each set of contacts being the neutral is shared?
Can we still somehow continue to split the fixtures into two panels dispite the shared neutral ? Thanks in advance for any thoughts.
 
You can't use the neutral from one panel with a circuit from a second panel and you can't tie the two neutrals together at the fixture so unless you go into the fixture and split the neutrals, you will not be able to feed them from two panels.
210.4(A)
 
aelectricalman said:
I am Planning to hang about 150 -6 lamp T5 4ft fixtures. Each fixture was originally to be wired where half feeds from panel S and half feeds from panel N. The circuits were getting wired back to contactors to be controlled independently. Well, the fixture came with a shared neutral rather than the specd 2-neutral set up in the fixture whips. Due to time we want to move forward placing the whole fixture in panel S (there is enough room) The set up proposed, so that we may keep the same configuration (at least similar), is to allow the first contactor to close, turning on the (low light setting) of three lamps and then when the customer wants full fixture lighting he can close the second contactor. Remember shared neutral. Has anyone used a similar configuration of contactors or is there a better idea for this application? I assume we cant 100% independantly operate each set of contacts being the neutral is shared?
Can we still somehow continue to split the fixtures into two panels dispite the shared neutral ? Thanks in advance for any thoughts.
Click to expand...

If this means that the entire fixture will be fed from one panel then yes you can use this setup, otherwise as Don said you have a problem.
 
don_resqcapt19 said:
You can't use the neutral from one panel with a circuit from a second panel and you can't tie the two neutrals together at the fixture so unless you go into the fixture and split the neutrals, you will not be able to feed them from two panels.
210.4(A)
Click to expand...

I underatand i cant tie two neutrals together from two panels. I understand each panel will need a neutral for its respective circuit. Im just not familiar with all the ways to skin a cat when it comes to lighting contactors. Sounds like its pretty cut and dry though huh! Thanks for the help.
 
The title of the thread is confusing, I would think the neutral as more of a common then a multi-wire circuit, these neutral are sized the same for all 6 lamps or just 3, so can be fed from the same circuit and or phase.

I never have had to use a split fed ballast, I have just split the 3 two lamp ballast to a 2/4 split, this would give the customer a 2 lamp low setting a 4 lamp medium setting, and a 6 lamp high setting
 
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