Determining Facility Voltage

[Nickl382]

What is the best way to determine what voltage the lighting fixtures in a facility are actually configured for?

Are you able to tell by simply by looking at a lighting panel for 480/277 if the fixtures were set up for 480 or 277?

Can you do this without using a volt-meter?

How often are lighting fixtures running at 480 V ?

Thanks

 

[don_resqcapt19]

Assuming a normal install, the 480 volt lights would be on two pole breakers, or sometimes on 3 pole, and the 277 on single pole breakers, but if this is a recent install, 210.4(B) may result in the 277 volt lights being on 3 pole breakers.

 

[jumper]

If this is interior, I think 210.6(D)(1) pretty much limits you to 277v for most installs.

 

[iwire]

If this is interior, I think 210.6(D)(1) pretty much limits you to 277v for most installs.

Not really.

If you have a 480Y/277 supply you can use 480 volt lighting.

 

[George Stolz]

I dislike the way that section is worded. It's just like 310.4, using the phrase "shall be permitted" when they intend to say "shall only be permitted."

It really looks as though they intend to keep 480V circuits away from lighting indoors.

 

[jumper]

Not really.

If you have a 480Y/277 supply you can use 480 volt lighting.

You are correct, I misread the article.

(D) 600 Volts Between Conductors. Circuits exceeding
277 volts, nominal, to ground and not exceeding 600 volts,
nominal, between conductors...

 

[iwire]

I dislike the way that section is worded. It's just like 310.4, using the phrase "shall be permitted" when they intend to say "shall only be permitted."

It really looks as though they intend to keep 480V circuits away from lighting indoors.

I agree 100%.

 

[iwire]

I misread the article.

I think that is an easy one to misread.

 

[don_resqcapt19]

I dislike the way that section is worded. It's just like 310.4, using the phrase "shall be permitted" when they intend to say "shall only be permitted."

It really looks as though they intend to keep 480V circuits away from lighting indoors.

Well I got 310.4 changed for the 2011 code, but did not have much luck with the other places where the code tries to use a specific permission (shall be permitted) to prohibit other installation methods. The intended use of "shall be permitted" per the NEC style manual, is to act as an exception to permit other installation methods.

 

[steve66]

I dislike the way that section is worded. It's just like 310.4, using the phrase "shall be permitted" when they intend to say "shall only be permitted."

I agree it would be better if they just said "shall only be permitted".

But I think the very first sentance of 210.6 -

"The nominal voltage of branch circuits shall not exceed the values permitted by 210.6(A) through (E)."

- is a very long way to say "only".