Transformer question

[Fordean]

Viewing a Transformer installed, Has 12250 volts approx. in / 480 out.
75Okva trans 6% imp.

I calculated 900 amp on 480 side. And label states that as well.
Service pulls 630 amps. on each phase +/- 30 amps.
High Temp on senso C phase is 110C. A = 95C, B = 97c.
Transformer c. I didnt right down.
On 480 side. They installed 1200 amp Main.

 

[Fordean]

125% of the 903 = 1143
1200 correct.

 

[augie47]

If the transformer is part of a NEC (as opposed to a POCO) arrangement the 1200 amp secondary meets NEC 450.3.
Conductor sizes, AIC rating, etc. not being considered.

 

[beanland]

OCPD or Temperature

OCPD or Temperature

Are you concerned about the breaker or temperatures?

110C is a tad warm for some transformers but not those with 150C rise design.

What is the transformer nameplate temperature rise?

 

[Fordean]

Are you concerned about the breaker or temperatures?

110C is a tad warm for some transformers but not those with 150C rise design.

What is the transformer nameplate temperature rise?

I will verify.