Voltage drop

[markimhoff]

On a 500' lighting branch circuit the first 250' is just pipe and wire. The last 250' has high-bay fixtures spaced at 20' intervals. Can the conductor running in the last 250' be #12 or #10 and the first 250' be larger to allow for voltage drop? Voltage in the circuit is 270V.

 

[ActionDave]

Yes it can. 270V is strange. Do you mean 277V?

 

[markimhoff]

Yes voltage is 277V.

 

[hurk27]

Yes but each section of conductors will have to be calculated to determine the correct voltage drop, also keep in mind that HID type high bay lighting will have a higher starting current then run current, voltage drop can keep some from starting and cause premature failure of the ballast and igniter's

but I have had good results even with a 5% drop at the lonest run, also include any switch leg runs if used.

 

[George Stolz]

I'd figure the run to the first light, then to the last light, and then just fake it for the lights in between.