inspectorjoe
Member
- Location
- Dover, NH USA
I have a question about the requirements of 250.122. the example is as follows. we have 4 parallel runs of MC Cable Feeders suppling metered equipment on upper floors of apartment building. The size of the wire is 350 KCMIL with a 1/0 Ground.
When we look at the requirements of 250.122 it states that you need a 4/0 ground for feeder size. if we look at the Article 250.122 F (!) & (2) it references the uses of cable trays, raceways, auxiliary gutters. NO LANGAUAGE FOR MC. no help, so we go to 310.10G conductors in parallel, it states that (5) Equipment Grounding Conductors, Sectioned Epuipment Grounding Conductors smaller than 1/0 AWG shall be permitted in multi conductor cables if/where installed in parallel that the combined circular mil area of the sectioned equipment grounding conductors in each cable complies with 250.122
the questions is
Can a 1/0 in parallel be used if it meets the equivalent or is greater than the requirement of 250.122, which would be a 4/0 AWG? Or is the permissive language only for conductors smaller than 1/0? Thank You in Advance
When we look at the requirements of 250.122 it states that you need a 4/0 ground for feeder size. if we look at the Article 250.122 F (!) & (2) it references the uses of cable trays, raceways, auxiliary gutters. NO LANGAUAGE FOR MC. no help, so we go to 310.10G conductors in parallel, it states that (5) Equipment Grounding Conductors, Sectioned Epuipment Grounding Conductors smaller than 1/0 AWG shall be permitted in multi conductor cables if/where installed in parallel that the combined circular mil area of the sectioned equipment grounding conductors in each cable complies with 250.122
the questions is
Can a 1/0 in parallel be used if it meets the equivalent or is greater than the requirement of 250.122, which would be a 4/0 AWG? Or is the permissive language only for conductors smaller than 1/0? Thank You in Advance
