# 277/480 main to 120/240 sub



## markmancuso3 (May 23, 2019)

i have a 277/480 panel without nuetral or ground. they want me to pull a 60 amp 120/240 sub. using a step down transformer. i have acsess to properly ground. my question is in regaurds to getting a proper nuetral 

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## LGLS (Nov 10, 2007)

120/240 or 3 phase 120/208 Y ?


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## CoolWill (Jan 5, 2019)

markmancuso3 said:


> i have a 277/480 panel without nuetral or ground. they want me to pull a 60 amp 120/240 sub. using a step down transformer. i have acsess to properly ground. my question is in regaurds to getting a proper nuetral
> 
> Sent from my SM-N960U using Tapatalk


You don't have 480Y/277 if you don't have a neutral. You just have 480. Just sayin'.

Buf your 208Y/120 panel gets its neutral from the transformer you install, not the primary.


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## frenchelectrican (Mar 15, 2007)

markmancuso3 said:


> i have a 277/480 panel without nuetral or ground. they want me to pull a 60 amp 120/240 sub. using a step down transformer. i have acsess to properly ground. my question is in regaurds to getting a proper nuetral
> 
> Sent from my SM-N960U using Tapatalk


if you see 480 volts sans neutral then you got delta connection and you can get them in single phase or three phase transformer to sized to the load what ya need it. 

you will get the neutral from secondary side and please follow the NEC codes related to the SDS system. 

Just becarefull if you get three phase with 240/120 volt delta secondary you have to watch out the rating on centre tap on that type of transformer. 

I would just get single phase transformer and be done with it.


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