We have multiple feeders from a piece of SWGR to multiple SWBDs. These feeders are 1600A’s each so we are running parallel feeders using a separately run #4/0 AWG Ground. The Contractor wrote an RFI in order to try a save the owner money and requested that we run a single ground cable for the multiple feeders and tap off the single ground into the SWBDs instead of running individual grounds back to the SWGR. His justification was that it met Article 250.122 (c). My initial thought was that this is something that can save money and seems to make sense in doing as such. I believe that further down in that article in 250.122 (f) for parallel feeders it points to article 310.10(h) and stipulates that the parallel feeder (phase, neutral, and ground) must adhere to 310.10 (h) (2) which says it must have the same length, consist of the same material, be the same size, have the same insulation, and be terminated in the same manner. This reads to me that the contractor’s suggestion is not allowed because the same length and circular mill, and being terminated in the same manner would not be satisfied.
Am I reading the code properly or is this not it’s intent?
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