Application of 250.134(2) Exception No. 2

[TiredEngineer1979]

I'm working on some utility scale BESS projects (not utility owned, so subject to electrical inspection) and I'm looking at the conflict, if you can call it that, between the requirement in 250.122(F)(1)(b) and the exception listed above in 134. The situation is a paralleled run between the Inverter unit and the battery container. It's multiple runs of less than 1500 VDC in multiple conduits. Per standard practice and 250.122(F)(1)(b), I would run a fully sized EGC in each conduit. In talking with some of our solar fellas, they're suggesting taking advantage of that Exception 2. I'm hoping to get some outside perspectives.

NEC 2023 250.122(F)(1)(b): Multiple Raceways. If conductors are installed in multiple raceways and are connected in parallel, a wire-type equipment grounding conductor, if used, shall be installed in each raceway and shall be connected in parallel. The equipment grounding conductor installed in each raceway shall be sized in accordance with 250.122 based on the rating of the overcurrent protective device for the feeder or branch circuit.

NEC 2023 250.134(2) Exception No. 2 For dc circuits, the equipment grounding conductor shall be permitted to be run separately from the circuit conductors.

I'm just a little concerned because we get a fair number of inspectors and independent engineers that look at Exceptions as they would dog mess on their loafers. Is this something anyone here runs across? Thanks for your input.

 

[infinity]

Per standard practice and 250.122(F)(1)(b), I would run a fully sized EGC in each conduit. In talking with some of our solar fellas, they're suggesting taking advantage of that Exception 2. I'm hoping to get some outside perspectives.

So if you're going to go against the standard practice and use the exception how will the EGC's be installed?

 

[TiredEngineer1979]

We'd run the EGC in a separate conduit parallel to the parallel conduits for the DC runs.