Light Fixture Wiring

[jrz126]

Hi All,

I recently started working at a lighting company and I've been put in charge of making the wiring diagrams for our fixtures. Most of the diagrams are already made, but I'd like to verify they are being done according to code.

The schematic above is for a 6-lamp florescent luminaire that has 3 separate circuits. Should there be a separate neutral wire for all 3 circuits?

 

[sameguy]

you need 1 ground

 

[DARUSA]

Mbc

Mbc

You need a MBC with a common handle ties .
3 ungrounded wire + 1 grounded ( neutral)+1 ground wire (Green or gray)

 

[LarryFine]

Welcome to the forum!

Should there be a separate neutral wire for all 3 circuits?

The NEC would not require that, as long as the line conductors share that single neutral for the entire circuit.

Whether the lighting controller is okay with that is something that the manufacturer would have to tell you.

 

[Microwatt]

You need a MBC with a common handle ties .
3 ungrounded wire + 1 grounded ( neutral)+1 ground wire (Green or gray)

You use gray for a grounding conductor?

 

[DARUSA]

You use gray for a grounding conductor?

no sorry!!! I should be wright gray on the neutral side for the 277 grounding is all ways green or bare conductor.

 

[jrz126]

Welcome to the forum!


The NEC would not require that, as long as the line conductors share that single neutral for the entire circuit.

Whether the lighting controller is okay with that is something that the manufacturer would have to tell you.

So I would need a seperate neutral if the 3 circuits were fed from multiple breakers? The diagram above is for a surgical troffer (we make hospital lights). The 3 seperate circuits are used so they have some control over the light output. I assume they are run to a 3-gang box and wired to regular wall switches and fed from the same breaker.
Is there any other electrical standard that would apply to hospital lights?

Another question -
My boss wants to start including quick disconnects on input wiring to the fixtures, to make it easier for installation and for the nec section 410.73 (g) requirment. We have these in stock right now:

and they work for most of the fixtures. Its the cases where I need to disconnect 4 or more leads (they only come in 2 & 3 terminal) that I'm not sure of. So how would I install disconnects on the above diagram?

 

[benaround]

So how would I install disconnects on the above diagram?

I only see three wires coming from each part, put the disconnects there. Saying that

these lights need 3 circuits is going to confuse people and get you in hot water, not to

mention possible loss of sales due to buyer thinking that they need to run 3 branch circuits

to the lighting panel. Saying that 1,2, or 3 levels of light can be obtained thru multi-switch

wiring might be more exact. IMO, I would let the installer make the connections at the

fixture and just have the 3 leads wired into the disconnect, on a seperate info sheet the

different configurations for switching could be included.

 

[cadpoint]

I can't say it as nice as Frank did!

I’ve looked and study and read these and looked and studied, again… maybe I don’t understand the aspects of an EMI Filter

As I’ve studied it.

Since it has a outline, it is making it a piece of equipment. This only presents the line side of the equipment.

How does each EMI get all the original 120-277V?

I don’t think you want the lowest line diagram arrangement.
I think you should feed from the bottom and rework out the shared neutral and ground circuit. To make all the EMI’s the same.
The panel breaker would be on the vertical hot run and snap switches or dimmers on the line side of the lamp(s).

The standard symbol should not be used, just “G”. You don’t want to chassis ground, physically, because you want to return to the main wires of the equipment circuit, and bond once.