Contactors Switching 1 leg of HID Lights

[ccrtech]

Did some service work the other day to replace a few 1000W MH lamps. I noticed that the fixtures had been wired with a contactor controlled by a photocell. Nothing strange with that, but the lights are 208V 2 pole, The contactor had been used to break only one leg of circuit, so the fixtures had one leg hot and one leg off, when the photo cell is on, the other leg powers up and the fixtures come on. I haven't seen this before, it works, but should it be replaced by a contactor that controls both legs? Just Curious.

Also this is my first post but I have been reading here for a while... A few of you guys seem to have come over from the EKR forum, which is pretty quiet these days.

 

[augie47]

I know of no requirement that both phases be broken by the contactor, and welcome to the Forum.

 

[iwire]

410.50 or 60 something prohibits it. maybe .54b off the top of my head

 

[augie47]

Bob, You are far wiser than I am, but I have yet to find the requirement.
Help !

 

[iwire]

Maybe 410.64 hid auxiliary equipment

It's in there somewhere.

 

[480sparky]

Maybe 410.64 hid auxiliary equipment

It's in there somewhere.

I've seen it too, but even eith the NEC on CD I can't find it. 410.64 is Liminaires as Raceways.

I'm thinking 410.130 Provisions for HID less than 1000v

 

[480sparky]

Bingo.

XIV. Special Provisions for Electric-Discharge Lighting Systems of More Than 1000 Volts
410.141 Control.
(A) Disconnection. Luminaires or lamp installation shall be controlled either singly or in groups by an externally operable switch or circuit breaker that opens all ungrounded primary conductors.

 

[SEO]

How about 410.93?

 

[480sparky]

How about 410.93?

Does the branch circuit supply the lampholder with the grounded, or does the ballast do that?

 

[augie47]

I've seen it too, but even eith the NEC on CD I can't find it. 410.64 is Liminaires as Raceways.

I'm thinking 410.130 Provisions for HID less than 1000v

That comes close but I can't find it there unless it was a MWBC and the OP sated 208.

Bingo.

XIV. Special Provisions for Electric-Discharge Lighting Systems of More Than 1000 Volts
410.141 Control.
(A) Disconnection. Luminaires or lamp installation shall be controlled either singly or in groups by an externally operable switch or circuit breaker that opens all ungrounded primary conductors.

I think 1000 MH is less than 1000 volts, is it not ?

How about 410.93?

Does the branch circuit supply the lampholder with the grounded, or does the ballast do that?

I'm kinda with 480sparky there..the circuit feeds the ballast, not the lampholder


I don't care for the OP's arrangement but I'm still hardpressed to say no.

 

[480sparky]

I don't care for the OP's arrangement but I'm still hardpressed to say no.

Keep in mind you are dealing with a controller, not a disconnect.

 

[iwire]

In the 2005 NEC I believe the section is 410.54.

 

[iwire]

http://forums.mikeholt.com/showthread.php?t=89443

 

[don_resqcapt19]

2008 code:

410.104(B) Switching. Where supplied by the ungrounded conductors of a circuit, the switching device of auxiliary equipment shall simultaneously disconnect all conductors.

 

[augie47]

Another educational day. Thank you, Don.

 

[LarryFine]

Does this apply to fluorescent lighting, too?

 

[480sparky]

Does this apply to fluorescent lighting, too?

Which one? I think there's about 4 references in here now.

 

[LarryFine]

Which one? I think there's about 4 references in here now.

Having to open all ungrounded conductors when powered line-to-line for general control.

 

[don_resqcapt19]

Does this apply to fluorescent lighting, too?

Yes, fluorescent are HIDs.

 

[dbuckley]

Irrespective of what the code says, I would say that common sense says all hot conductors should be switched together.