Goatprod
Member
- Location
- Long Beach
- Occupation
- Electrician
Following multiple threads, it appears that 705.12(B)(2)(c) would allow for a whole world of backfeed possibilities.
Hypothetically:
100 amp max rated MSP with 100 amp breaker.
Filled with standard household loads.
If one were to add a sub panel, and reconfigure the MSP to only have two loads, call it 2x50 amp breakers, then:
With the new sub panel having a max rating of 125 amps (on the bus bar), as well as the relocated house loads, would this allow the use of a 40 amp max backfeed PV breaker located at the opposite end of ?
The 120 percent rule allows for 100 amp backfeed breaker on said busing. (125 x 1.2 - 50 = 100).
The sum of the ampere ratings of all overcurrent devices equals the rating of the bus bar within the MSP.
And the backfeed breaker within the sub panel follows the 120 percent rule.
The 120 rule within the MSP would only allow for a 20 amp backfeed breaker.
This scenario would allow for a larger sized pv system to be installed without having to perform a line side tap or a main panel upgrade.
Looking forward to hearing what I’ve misinterpreted.
Thank you for your knowledge people.
Hypothetically:
100 amp max rated MSP with 100 amp breaker.
Filled with standard household loads.
If one were to add a sub panel, and reconfigure the MSP to only have two loads, call it 2x50 amp breakers, then:
With the new sub panel having a max rating of 125 amps (on the bus bar), as well as the relocated house loads, would this allow the use of a 40 amp max backfeed PV breaker located at the opposite end of ?
The 120 percent rule allows for 100 amp backfeed breaker on said busing. (125 x 1.2 - 50 = 100).
The sum of the ampere ratings of all overcurrent devices equals the rating of the bus bar within the MSP.
And the backfeed breaker within the sub panel follows the 120 percent rule.
The 120 rule within the MSP would only allow for a 20 amp backfeed breaker.
This scenario would allow for a larger sized pv system to be installed without having to perform a line side tap or a main panel upgrade.
Looking forward to hearing what I’ve misinterpreted.
Thank you for your knowledge people.