single phase 480

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The 480/240 system is common here for highway lighting. 480V grounded two-wire wouldn't be hard to do either but the meter might be hard to find, 480V Form 1S?
 
RB1 said:
The 480/240 system is common here for highway lighting. 480V grounded two-wire wouldn't be hard to do either but the meter might be hard to find, 480V Form 1S?
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Easy is right, use same transformer and ground one of the ends and leave center tap float.

Next question is why not ground center tap if there is one available? Only advantage is one less conductor to service equipment, and is likely not a very long run to service in most cases, otherwise why not have 240 to ground instead of 480?
 
It is 2 pole 480V with neutral for highway lighting. Neutral is only being used in the control cabinet for the photo eye which is rated at 305V. Light poles are also fused at the bases for protection. Threw me off a bit with the single phase and neutral and also just shifted divisions from airports to traffic. Didn't have a grasp on it till they gave me all the parts for the lighting control cabinet. And yes... In fact I was away in a bucket truck :D
 
Cavie said:
Most likely grounded system. Hot (480) neutral and ground. Took me a while to get my head wrapped around it. Light fixture ballasts don't care about one wire or two wire. #6 is usually the minimum wire size. 20 amp circuits. 20' ground rods at every pole. 40' at every service. 2" min conduit size.
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Why would the ballast care?
 
brian john said:
Why would the ballast care?
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As I stated, They dont. I had electricians try to tell me the needed special ballast to use on the 480 to ground systems. They don't. One of my electricians had a brain fart last week and told me the 12 volt light he was working on wouldn't work because it had a 120/277 switch controlling it! DUH! I wish they had a name for the 480 to ground system. It's printed on plans by engineers a 480 single phase but that causes the confusion we had here.
 
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