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 Post subject: Working on 277 volt lighting systems
PostPosted: Thu May 23, 2013 6:48 pm 

Joined: Fri Apr 12, 2013 6:35 am
Posts: 8
Hello everyone,

Once again I have been presented with a question or a scenario that I have not been able to address to a degree of certainty I'm comfortable with. In our facilities we have mainly 277 volt fluorescent lighting. Under normal circumstances our electrical staff has to de-energize to change a ballast. We have just run into some fixture that have been recently installed with quick connect options where in small print it states de-energized state is not required for ballast replacement. Has anyone here run into these and how does 70E address this. I'm still looking. your input is greatly appreciated. Thank you

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PostPosted: Mon May 27, 2013 9:02 am 

Joined: Fri Aug 26, 2011 7:38 am
Posts: 32
Location: Baltimore, MD
As a practical matter the amount of arc flash energy at a luminaire, protected by a 20-ampere circuit breaker, is not much. That said, it is better to turn off the circuit, or at least the switch, before you begin work. To follow all the rules, one would lock out and tag out the circuit breaker.

The challenge in the field is that in many cases luminaires served by the circuit are the only sources of light in a room, and if you turn off the circuit you are working by flashlight. The advantage of the ballast disconnect (ASSUMING IT WAS INSTALLED PROPERLY AND IS NOT DEFECTIVE) is that it allows you to work on one luminaire while leaving the rest on.

The correct procedure includes safe use of a good ladder and use of eye protection. Remove the lens or other fittings between you and the lamps. Remove the fluorescent lamps ("tubes"). Remove the ballast compartment cover.

You will see the circuit conductors (usually a gray neutral wire and a brown, orange, or yellow "hot" wire) connected to the ballast's input leads by a finger-safe disconnect- like a male and female connector. Separate the two parts. The live ends of the circuit conductors are safely insulated by the disconnect. Replace the ballast, handling the output leads (to the sockets) first. Snip off the input leads of the bad ballast so it won't be reused again by accident.

If you are fortunate, you have the matching disconnect piece available to put on the new ballast's input leads. Attach the matching disconnect piece onto the new ballast's input leads. Replace the ballast cover and the lamps. Reassemble the luminaire.

If you are not fortunate- my experience with ballast disconnects is that they aren't listed for reuse. Therefore you will have to provide new pieces on both the ballast's input leads AND the circuit conductors inside the luminaire. Now you should deenergize the circuit.

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PostPosted: Tue May 28, 2013 5:10 am 
Sparks Level

Joined: Wed Oct 29, 2008 6:06 am
Posts: 136
Location: Michigan
I think the ballast disconnect plugs are great! I believe they are classified as a disconnecting means per NEC 410.130(G). Then as far as lockout is concerned, I classify it as cord and plug connected which allows it to fall under the exclusive control exception.

However, if there are no ballasts disconnect plugs (i.e. wire nuts only), then the circuit breaker must be shutoff and locked out before changing the ballast.

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PostPosted: Fri May 31, 2013 4:34 am 
Sparks Level

Joined: Fri May 01, 2009 9:10 am
Posts: 73
I agree with A King and suggest you take it 1 step further... make it company SOP that any ballast replacement is installed with listed ballast connectors to facilitate future replacements.

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