Hello everyone,
I have lost track of the code as it applies in the new code book and I need some input.
I have a job where the interconnection location is on an exterior meter main combo with only bus bar attached to main breaker and it directly leaves the MCB in an ser and inside to an interior panel board that is MLO so there's no main breaker.
Now,
There is no indication of what the meter main bussbar actually is or any form or part number I can find. The MCB is a 150 amp single phase.
Following the usual 120% rule that says that the ampacity of the breakers feeding the panel board cannot exceed 120 of the bussbar rating. I know that the size of the sub feeds was designed for the breaker which was derived from the original load calculation.
The sum of all of the branch circuit breakers in the panel well exceeds the rating of the bussbar and wire as they're intermittent as the original calculation would've shown.
My concern is
now,
. Safely assuming it's a 150 amp panel board inside as it would need to be atleast of that ampacity I end up at. If both the meter main and panel 150 amp rated buss then I have 30 amps I can back feed 30 ps to that wire.b
My issue is I need to backfeed 41 amps realistically at 125 of outpout. Which Is why I wish It had labels somewhere to prove the rating of the bussbar over the side of the rated breaker.well never find a 41 amp breaker so we have to use the next size up which is 50 amp fuses that I've ever seen.
So following this rule I'm only require to see siza of the buss bars that these wires are attached to.
My question/ concern is that if there's no main ocpd on the panelboord and the circuits cuü
I have lost track of the code as it applies in the new code book and I need some input.
I have a job where the interconnection location is on an exterior meter main combo with only bus bar attached to main breaker and it directly leaves the MCB in an ser and inside to an interior panel board that is MLO so there's no main breaker.
Now,
There is no indication of what the meter main bussbar actually is or any form or part number I can find. The MCB is a 150 amp single phase.
Following the usual 120% rule that says that the ampacity of the breakers feeding the panel board cannot exceed 120 of the bussbar rating. I know that the size of the sub feeds was designed for the breaker which was derived from the original load calculation.
The sum of all of the branch circuit breakers in the panel well exceeds the rating of the bussbar and wire as they're intermittent as the original calculation would've shown.
My concern is
now,
. Safely assuming it's a 150 amp panel board inside as it would need to be atleast of that ampacity I end up at. If both the meter main and panel 150 amp rated buss then I have 30 amps I can back feed 30 ps to that wire.b
My issue is I need to backfeed 41 amps realistically at 125 of outpout. Which Is why I wish It had labels somewhere to prove the rating of the bussbar over the side of the rated breaker.well never find a 41 amp breaker so we have to use the next size up which is 50 amp fuses that I've ever seen.
So following this rule I'm only require to see siza of the buss bars that these wires are attached to.
My question/ concern is that if there's no main ocpd on the panelboord and the circuits cuü
