Landing#350 aluminum feed conductor in too small a buss bar lug

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Amperess

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Palm Springs
I've got a 3 phase 225 amp load center with #350 aluminum feeders. Phase C has 10 inches of insulation melted back from the lug that needs replacing (cannot tighten or loosen) due to extreme heat. The panel is feeding 6-40amp 3 pole breakers, 6-20amp 2pole breakers (all mentioned run wall a.c.'s), 12-20amp single pole breakers for lighting and outlets. This is the desert and a.c.'s are always running. The main breaker cabinet is approx. 60 feet away.
I am concerned with how the main feed has been shaved to fit into the lugs during original install. And told that replacing that size wire with copper is too hard to do. Besides, I plan to replace the 225 amp with a 400amp/ bolt on breakers to better accomadate during full house. ( It's a hotel) And wouldn't that allow them get more use out of the older a.c. wall units?
Any advice?
 
Use an aluminum to copper reducing compression connector. T&B, Burndy and others make them that take 350 on one end and have a #4/0 copper pigtail or pin the same size as 4/0 on the other. Cut out the damaged aluminum and splice in #4/0 or 250 kcmil copper to go under the lug. (Depends on how much room you have).

Do the same at both ends.

(I didn't check that 350 was good for the loads you mentioned, which would cause other problems).
 
If I understand correctly, replacing the 225 amp breaker with a 400 amp breaker (actual setting) using 350 kcmil AL (one per phase) to feed a MLO panel would be a violation of a couple of NEC sections.
 
augie47 said:
If I understand correctly, replacing the 225 amp breaker with a 400 amp breaker (actual setting) using 350 kcmil AL (one per phase) to feed a MLO panel would be a violation of a couple of NEC sections.
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I am not sure what breaker he is actually planning to replace from his description.
 
Nothing wrong with replacing panel with 400 amp panel, but if the 350 aluminum remains it must have 250 amp max overcurrent device protecting it.
 
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