Design LED fixture wiring

[BillConnerFASTC]

Looking at using a 0-10 volt LED house light using a Pathway 1004 demultiplexer, and looking for experience and views on separate conduits for the line and 0-10 to each fixture versus a shielded pair in same conduit with line. It seems shield pair with shield tied to demultiplexer is as good as or better than separate conduit, but not a simple issue. Also code - I think you can run the shield lo-vo pair in same conduit but perhaps it has more to do with barriers and ratings of 1004 device. I have asked Pathway same question but looking for as much as I can find.

 

[JD]

Don't think you can run control in the same conduit as line. Concept is a fire in the conduit could cause line voltage to end up in the control cable. ST could provide chapter and verse. I would stick with shielded cable outside the conduit. 10v systems are usually pretty hardy. Remember using 25 pair phone cable to run a 48 channel for about 4 years in one location so that I didn't have to pull it every time we came and went. Kind of disposable snake. Never had any problems.

 

[Dionysus]

You CAN NOT put wires rated for under "line voltage" in the same conduit as wires running line voltage. IE 300v rating on cable.
You also shouldn't run "low voltage" in the same conduit as "line voltage", of course there are exceptions. The idea is that if a line voltage wire gets damaged, and so does the other, you don't want 120v+ running down your 12v line. You are also not supposed to mingle AC and DC in the same conduit for much the same reason.
At very least all wire must be rated for "line voltage", still, I wouldn't do it. Run a separate conduit for your control, its just better that way.
Then again, 99% of the time with 0-10v control wire I just run it along beside the conduit and zip-tie it on, using appropriate cable of course.

 

[BillConnerFASTC]

One of the problems is that it is Chicago - which has stricter codes and would not permit the wire tie on the conduit - and it's all very visible in old building - why the single conduit had appeal. But probably not going that way.

 

[Dionysus]

One of the problems is that it is Chicago - which has stricter codes and would not permit the wire tie on the conduit - and it's all very visible in old building - why the single conduit had appeal. But probably not going that way.

Not even if you use a cable like securex? (Low voltage Armored cable for fire alarm etc)

 

[BillConnerFASTC]

it would look like crap where this is. One or two conduits would just look better. Looks like two conduits. Still trying to figure out how to get low voltage and line through same box and terminate at fixture.

 

[sk8rsdad]

Doesn't NEC 725.54 allow for mixed high and low voltage conductors in the same raceway under one of the exceptions? I seem to recall a clause about it being acceptable when the low voltage conductors are associated with the equipment and the insulation is rated for the highest voltage. There might also be clauses in there about installation details and maintaining separation of connections.

 

[Dionysus]

it would look like crap where this is. One or two conduits would just look better. Looks like two conduits. Still trying to figure out how to get low voltage and line through same box and terminate at fixture.

Visible? Then Two conduits is the way to go!

Two real options, depending on local codes.

1) Keep divided until the fixture
2) Keep divided until the box before the fixture, perhaps with a divider inside the box (some have provisions for this, like wiremould)

As long as the connections for low and line voltages are in the same part of the fixture (not divided) they can be along side (suggest a wire rated for 300v), should be brought together only as close to this point as "practable". If the fixtures have separate points for them you'd have to come in separate.
Commonly for things like emergency lighting we run the 12vDC with the same [HASHTAG]#12[/HASHTAG] wire used for the line voltage. Keeping them in separate conduits and bringing together into the same 4x4 boxes before running down to the emergency light or battery pack. This allows for them to share the box as long as labeled properly, but not the same conduit until the point that they would "have to run together".
The wire we typically use for fire alarm systems is also rated for 300v, with fire rating etc (like securex). However either way I'd run it by an inspector before you decide.

Doesn't NEC 725.54 allow for mixed high and low voltage conductors in the same raceway under one of the exceptions? I seem to recall a clause about it being acceptable when the low voltage conductors are associated with the equipment and the insulation is rated for the highest voltage. There might also be clauses in there about installation details and maintaining separation of connections.

EXACTLY, as long as the wire is rated for the 120v or whatever, you are golden, but you are required to separate "when you are able to". Around here, that means its up to the inspector.
I HAVE run 12vDC and 120vAC down the same conduit the whole way. But of course using all [HASHTAG]#12[/HASHTAG] stranded wire. Im sure you could do this in chicago.

 

[STEVETERRY]

Looking at using a 0-10 volt LED house light using a Pathway 1004 demultiplexer, and looking for experience and views on separate conduits for the line and 0-10 to each fixture versus a shielded pair in same conduit with line. It seems shield pair with shield tied to demultiplexer is as good as or better than separate conduit, but not a simple issue. Also code - I think you can run the shield lo-vo pair in same conduit but perhaps it has more to do with barriers and ratings of 1004 device. I have asked Pathway same question but looking for as much as I can find.

Two conduits required.

ST

 

[BillConnerFASTC]

Two conduits required.

ST

But can they go into and through same box that surface fixture mounts to? I don't think the Incito cylinder has provisions for separate line and low voltage entrances.

 

[n1ist]

Actually, it depends... Check the lights AND demux; if the 0-10V wiring is listed as Class 1 or Class 1/Class 2, then you can run that wiring in the same conduit (or even the same cable assembly as is often done for DALI) as power, as long as the control wire has insulation rated higher than the AC voltage (I'd use 300V wire), and there are no other wires in the conduit (the low voltage wire must be "associated with" the high voltage - like 0-10V control or some thermostats).

The last project I designed (for a major commercial lighting company) had both DALI and 0-10V that were Class 1/Class 2 rated (proper trace and component spacing, optoisolator or transformer isolation, etc) so you could wire them up either way.

/mike