227volt Nuetral needed

[Toros]

Hi,
I have to hook up 10 1000w @ 277 volt light fixtures and some receptacle @120v in an existing commercial building
that has 480v, 3- wire service and a 240vv, 1 ph., 3 wire service available
( no nuetral or return leg in none of them).

I think i have to provide a large size type transformer that can be supplied by 480v as primary
and gives out a nuetral terminal that can be used for both types of load (120v or 277v) ????????

thank you

 

[jumper]

Hi,
I have to hook up 10 1000w @ 277 volt light fixtures and some receptacle @120v in an existing commercial building
that has 480v, 3- wire service and a 240vv, 1 ph., 3 wire service available
( no nuetral or return leg in none of them).

I think i have to provide a large size type transformer that can be supplied by 480v as primary
and gives out a nuetral terminal that can be used for both types of load (120v or 277v) ????????

thank you

First, are you sure you do not have a neutral? 250.24(C) requires that the service neutral is brought to the service discnnecting means.

If you have a 3W 240V 1P service you have a neutral/grounded conductor. Is the 480V service 1P or 3P? If 3P, somebody screwed up.

 

[augie47]

Was this not covered adequately in your thread on the same subject a few months back ?
http://forums.mikeholt.com/showthread.php?t=174479&p=1709120&highlight=#post1709120

 

[jumper]

Was this not covered adequately in your thread on the same subject a few months back ?
http://forums.mikeholt.com/showthread.php?t=174479&p=1709120&highlight=#post1709120

Why, I have been hornswaggled I say.

 

[kwired]

First, are you sure you do not have a neutral? 250.24(C) requires that the service neutral is brought to the service discnnecting means.

If you have a 3W 240V 1P service you have a neutral/grounded conductor. Is the 480V service 1P or 3P? If 3P, somebody screwed up.

"480v, 3- wire service" could mean corner grounded delta - there would be no neutral on that system. One other possibility is a 240/480 single phase system.

 

[augie47]

Since this appears to have been adequately covered in the previous thread noted, I am closing this,.