air condition feeds

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puckman

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ridgewood, n.j.
i have a store with about a 400 amp service 3 phase 4 wire 240 volt service. there is a 3pole 200 amp cb feeding 4 panels 100amp and 150amp panels.and another 200 amp single phase panel. no main cb . both 200 amp feeds come right out from the ct cabinet to their 200amp panel with 3/0 copper. my problem is we aregetting 2 ac units. the main unit requires a min. of 125amp 3phase 230volt and the second needs 40amp 3phase 230volt. i can find a panel for the 40 amp ac unit but not the 125amp. hows the best way to handle this. there isn't apanel that will take 125 amp cb in the place. the larger unit will be replacing 2 units with a 60amp feed for each one. anyone have any ideas?
thanks for any help.
 
ac

ac

there is the ct then trough, out of trough is a 200 amp 3 phase cb that feeds about 4 panels. and next to the cb is 200amp 1 phase panel 40 circuit , filled.
each 200 amp feed comming out of ct has its own 3/0 feed. trough is about 3 ft.
 
- 1 feed comming from ct to 200 amp 3 pole cb .feeding 4 panels pulling 130amps atlast reading.
second feed comming from ct to single phase 200amp panel which can't help. can not shut off power to tap off of.
can a second service be installed for new equipment or does the present service have to be incrased. thanks for the repleys.
the load should not change , if it does it would be very little since we are replacing atleast 3 units.
the problem comes in because of it size requiring 125 amp min. feed
 
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puckman said:
why? - 1 feed comming from ct to 200 amp 3 pole cb .feeding 4 panels pulling 130amps atlast reading.
second feed comming from ct to single phase 200amp panel which can't help. can not shut off power to tap off of.
can a second service be installed for new equipment or does the present service have to be incrased. thanks for the repleys.
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From what I can understand of your situation, you cannot have two service to the building. You must increase the service size.
 
I estimate over 200A new demand on your 3-phase service. The 200A circuit breaker won't be able to handle that. Also, I think you said the 1-phase panel is main lug only which is fed straight out of the CT cabinet. A new inspector won't like seeing that. The service needs to be revised. The Utility may need to upsize their transformer because of the larger motor.

This may be a good time to consider changing the building to 208V, 3ph, 4 wire. Are the new 240V motors already purchased? Any other 240V loads in the building? If yes, then you may need to stay at 240V. It's hard to balance a 240V, 3ph, 4 wire system.
 
AC feed

AC feed

It seems that your only option is to upgrade the service to a 208 volt 3 phase system & rework the existing distribution panels.

It appears that there will be to much of a load on the 200 amp circuit breaker


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