Transformer feeding two panels

Status
Not open for further replies.
tom baker

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
I saw an interesting transformer panel installation I can't quite get my mind around.
480 primary 100 amp feed to 75 KVA transformer 480x120/208
secondary to a 200 amp main 42 space 120/208 panel, bottom fed.
At the panel top lugs, 4/0 copper to an adjacent 30 space 120/208 panel.

Seems like there should be a main for the second panel, as its not protected where it receives its supply.
 
tom baker said:
I saw an interesting transformer panel installation I can't quite get my mind around.
480 primary 100 amp feed to 75 KVA transformer 480x120/208
secondary to a 200 amp main 42 space 120/208 panel, bottom fed.
At the panel top lugs, 4/0 copper to an adjacent 30 space 120/208 panel.

Seems like there should be a main for the second panel, as its not protected where it receives its supply.
Click to expand...

The "panel top lugs" sound like feed through lugs. If so, the 230A feeder and second panel (assuming it has at least 200A bussing) are protected by the 200A main in the first panel.
 
Status
Not open for further replies.
Top