Paul_NJ
New User
- Location
- New Jersey
- Occupation
- Retired
This may have been addressed before: forgive me if I missed it.
I am seeking to replace and upgrade the subpanel in an old farmhouse. I already installed a new 200 amp main. Now seeking to increase it's subpanel capacity from 50 to 100 amps and wish to keep the AWG 6 wire already in place, and just add another set of feeder wires . I understand the purpose of NEC 310.10 is to address the possible hazards of paralleling two 50 amp capable conductors under a single 100 amp main panel breaker, where a conductor could find itself facing 100 amps and thereby under-protected due to any number of scenarios. But what if 2-double 50 amp main panel breakers feed conductor pairs that leave the main travel in separate conduit raceways to the subpanel, and are connected to the busbars there? Seems like each feeder conductor will be protected from ever seeing above 50 amps. And 100 amps will be delivered to the subpanel. Current only flows if a device plugged into the subpanel is taking it. Won't both subpanel legs draw as needed from the main, and all feeded conductors are protected at 50 amps. Isn’t this a different scenario from what 310.10 is addressing (feeder conductors are not protected unless the current hits 100 amps, well above it’s ampacity?). Sorry if I'm missing something . . . . .
All this to add more AWG 6 instead of replacing it all with AWG 2 . . . . saving $500 . . . .
Thanks for your help.
I am seeking to replace and upgrade the subpanel in an old farmhouse. I already installed a new 200 amp main. Now seeking to increase it's subpanel capacity from 50 to 100 amps and wish to keep the AWG 6 wire already in place, and just add another set of feeder wires . I understand the purpose of NEC 310.10 is to address the possible hazards of paralleling two 50 amp capable conductors under a single 100 amp main panel breaker, where a conductor could find itself facing 100 amps and thereby under-protected due to any number of scenarios. But what if 2-double 50 amp main panel breakers feed conductor pairs that leave the main travel in separate conduit raceways to the subpanel, and are connected to the busbars there? Seems like each feeder conductor will be protected from ever seeing above 50 amps. And 100 amps will be delivered to the subpanel. Current only flows if a device plugged into the subpanel is taking it. Won't both subpanel legs draw as needed from the main, and all feeded conductors are protected at 50 amps. Isn’t this a different scenario from what 310.10 is addressing (feeder conductors are not protected unless the current hits 100 amps, well above it’s ampacity?). Sorry if I'm missing something . . . . .
All this to add more AWG 6 instead of replacing it all with AWG 2 . . . . saving $500 . . . .
Thanks for your help.
