archimedes
Member
Ok, I'm having an argument with a fellow at work. Right now we have 2 circuits from 2 separate systems being spliced in the same metal box. One of the circuits is 110v being fed from a 3 phase 208 system, and the other is a 110v circuit being fed from an optional standby system. My contention is that because both systems are being spliced within the metal box, they both need to be bonded to the box. Therefore I said that having one pigtail coming off of the ground screw, and then splicing all the EGC's together would suffice.
HIS contention is that no, because they are 2 separate systems the EGCs should remain separate. We both spent time scouring through the code and neither of us could find a definite answer one way or the other. It makes sense to me that because all the EGC is doing is maintaining the same potential between raceways, enclosures, etc. and providing a path to ground in case of a fault, that there would be no adverse effects from splicing them all together. The only code I could find to solidify my argument is 250.148. If they both have to be bonded to the box, then it doesn't matter if it is 2 separate ground screws or if they're both under the same wire nut. They're going to be connected regardless.
I would really appreciate some opinions, and preferrably opinions with code sections. Thanks in advance
HIS contention is that no, because they are 2 separate systems the EGCs should remain separate. We both spent time scouring through the code and neither of us could find a definite answer one way or the other. It makes sense to me that because all the EGC is doing is maintaining the same potential between raceways, enclosures, etc. and providing a path to ground in case of a fault, that there would be no adverse effects from splicing them all together. The only code I could find to solidify my argument is 250.148. If they both have to be bonded to the box, then it doesn't matter if it is 2 separate ground screws or if they're both under the same wire nut. They're going to be connected regardless.
I would really appreciate some opinions, and preferrably opinions with code sections. Thanks in advance