texmln
Well-known member
Guys, I need your input on the final wiring of my sub-sub panel. This installation is in a large metal building on a ranch.
The main panel is outside on a shed about 100 feet from the large metal building and the first sub is inside the metal building and is a 125 amp main lug that is double grounded separately to a buried rod and one of the main steel supports bolted to the slab. This panel was installed by a professional electrician.
I installed a second 125 amp main breaker panel 60 feet away, also inside the metal building, fed from the sub in the metal building by three #1 conductors (two hot, one neutral) and one #4 ground. This panel powers a small living area and has a number of outlet and lighting circuits plus one heavy draw via two 40 amp double poles that feed a tankless hot water heater (infrequently used).
In any case, I wired up my new sub with two hot into the main breaker, my neutral into the neutral bus, and my ground into a separate ground bus that is not bonded to the neutral. My questions is, do I need to double ground this second sub panel? I have read that I do not have to because it is in the same "dwelling" as the first double grounded sub but I have seen some conflicting information in other places. Do you agree that no further grounding of the second panel is required? Would it be helpful to gound it anyway or could it potentially create a problem?
Thanks for your input!
The main panel is outside on a shed about 100 feet from the large metal building and the first sub is inside the metal building and is a 125 amp main lug that is double grounded separately to a buried rod and one of the main steel supports bolted to the slab. This panel was installed by a professional electrician.
I installed a second 125 amp main breaker panel 60 feet away, also inside the metal building, fed from the sub in the metal building by three #1 conductors (two hot, one neutral) and one #4 ground. This panel powers a small living area and has a number of outlet and lighting circuits plus one heavy draw via two 40 amp double poles that feed a tankless hot water heater (infrequently used).
In any case, I wired up my new sub with two hot into the main breaker, my neutral into the neutral bus, and my ground into a separate ground bus that is not bonded to the neutral. My questions is, do I need to double ground this second sub panel? I have read that I do not have to because it is in the same "dwelling" as the first double grounded sub but I have seen some conflicting information in other places. Do you agree that no further grounding of the second panel is required? Would it be helpful to gound it anyway or could it potentially create a problem?
Thanks for your input!