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#73226 - 12/19/06 08:00 PM transformer ocp
DetroiterRob Offline
Member

Registered: 05/16/04
Posts: 34
Loc: Dearborn, MI, USA
ok i dont do a whole lot with hooking up transformers outside of control equipment so i am kinda stumped with this little job in our shop, we are getting an axle test stand to run for acouple of weeks and i am currently working on the hookup and we just happen to have a 225kva 240-480 transformer laying around our shop. leftover from the previous tennants i guess. anyway, in the 05 book, table 450.3(b) lists primary protection as 125% and secondary not required, or primary as 250% with 125% on the secondary, which is easy enough to figure out, what is making me scratch my head here is where is secondary required, i plan on having it to cya with the equipment but my boss is trying to save some money and im trying to do this right. thanks, Rob

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#73227 - 12/20/06 11:11 AM Re: transformer ocp
resqcapt19 Offline
Member

Registered: 11/10/00
Posts: 2209
Loc: IL
Rob,
If you have been reading Article 450, that only covers the overcurrent protection for the transformer itself. The secondary conductors will require protection per 240.21(C).
Don
_________________________
Don(resqcapt19)

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#73228 - 12/20/06 07:38 PM Re: transformer ocp
DetroiterRob Offline
Member

Registered: 05/16/04
Posts: 34
Loc: Dearborn, MI, USA
thanks, just what i needed to know

rob

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