What are the options?

[27hillcrest]

I have a project at a ski area that is looking for a lighting retrofit. Currently the lights are fed 480v. The new lights that have been speced by the poc are 277v. So the delema is... the new lights now need a neutral and the only available wire is the messenger cable which is currently the ground. Are there any provisions in the code that would allow this? The overhead lighting wire has been in place for many years and are attached to many trees and poles over the years.

TIA

 

[Twoskinsoneman]

what wiring method is used for the 480v lights now? There may be a way to identify one of the 480v ungrounded conductors as a grounded conductor.

200.6(E) ex1

 

[Smart $]

Quit thinking workaround and fix the real problem.

 

[Twoskinsoneman]

Quit thinking workaround and fix the real problem.

?? The real problem being the color of the insulation on the existing wire?

 

[George Stolz]

I thought the problem was the voltage of the proposed lights.

Are there only two phase conductors and an equipment grounding conductor currently?

 

[BAHTAH]

What are the options

What are the options

See if there is an option for a multi-tap ballast for the fixtures. Many fixtures come that way, worth checking.

 

[hurk27]

There might be another problem?

At 277 volts the fixtures will require more current, depending upon the amount of wattage new verses old and existing circuit, might require new circuit after all or returning of fixtures for the correct ones?

 

[27hillcrest]

The lights are fed with 480v single phase by a tryplex cable 3hots and a messenger cable. The disconnect feeding the lights has a mining cable underground with three hots and bare ground. There is no way to get a neutral to the panel feeding the lighting disco.

 

[Twoskinsoneman]

Not to get toooo side tracked but is it code compliant to use messenger cable as EGC?
I thought it wasn't.

 

[renosteinke]

What is 480 single phase?

If you have the usual 480, then you have two 'hots' to each fixture. You need the ne fixtures to have ballasts for 480. I have not seen multi-taps that cover 480- maybe you can find one, but I'd make sure before placing the order.

PoCo is specifying? Sounds like you need to have those specifications clarified. I can't think of any PoCo that would require 277v fixtures on a 480v circuit.

Messenger as ground? That sounds like the wires are strung through the air. Sounds pretty easy to add a neutral, if you need one. Messenger as neutral? Not a chance. These are lights, not a service drop.

 

[Smart $]

... PoCo is specifying? ... Messenger as neutral? Not a chance. These are lights, not a service drop.

If PoCo doing the spec'ing, I have to ask if under NEC purview to begin with???

 

[ritelec]

I have a similar dilemma with messenger wire feeding throughout a camp. (3 hots and ground....no neutral)

As in my case, I think Smart $ nailed it.

Quit thinking workaround and fix the real problem.

 

[renosteinke]

"PoCo is specifying" needs to be clarified by the OP. The 'specifying' can be everything from un-metered, PoCo owned lights ove the substation to just the PoCo's guidelines in order to get their energy rebate.

It's been my experience that PoCo's maintain their own lights ..... and they're not too worried about paying the electric bill

 

[Twoskinsoneman]

Messenger as ground? That sounds like the wires are strung through the air. Sounds pretty easy to add a neutral, if you need one. Messenger as neutral? Not a chance. These are lights, not a service drop.

I don't think there is any provision for using a steel messenger cable as an EGC.