Code violation

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anbm

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Designer
I went to job site and saw this:

A 480/277V panel (panel A) with 125A main breker, this panel feeds a 75kVA transformer locates in same room. There is no breaker in panel A to feed 75kVA transformer.

The 75kVA transfomer feeds 3-section panel.

Section 1 has 300A main breaker.

Section 1 has (2) 150A breakers feed section 2 and 3 accordingly.

Will above design violiate code for transformer and panel protection rule???
 
so how is the trans fed?
what is the sec Voltage.
Length of pri conductors
length of sec conductors
is it grounded??

Do the sec conductors leave the enclosure that house the trans?
 
Xfmr secondary voltage is 208/120V. They are all side by side with 10'. Couldn't verify wire size.
 
As Bob says, as long as the conductors are properly sized it might well meet Code. There is no problem in reference to breaker sizes.
 
Now I am curious if the 125A main breaker in 480V panel is actually the breaker feeds xfmr not the main breaker to protect that panel. But I did see they labeled it as "main breaker" and located at top of panel.
 
It's possible it's a feed-thru panel and that breaker servres as the panel main and the the transformer main also. That is not uncommon.
It is not oversized per 450.3
 
anbm said:
Now I am curious if the 125A main breaker in 480V panel is actually the breaker feeds xfmr not the main breaker to protect that panel. But I did see they labeled it as "main breaker" and located at top of panel.
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It would not matter if it just protects the transformer or if it protects both the panel and the transformer.

Now that said, I would be surprised if the panel is not a main lug panel and the 125 is just for the trans. I kind of expect the 480 panel is actually a 225 amp MLO panel with a 125 amp sub feed.
 
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