Multi metering Equipment grounding?

[qopanel]

We are working on a 12 unit office/warehouse. The main breaker service rating is 1200 amp 208v 3phase 4wire. The main circuit breaker cabinet neutral is bonded to the cabinet, and the neutral is also bonded to the main water and a supplementary grounding electrode. There are 12 200 amp meter positions w/disconnects. The feed to each unit starts out in heavy wall and when it go's inside the building under the concrete and turns into pvc, then back up into heavy wall as it comes out of the concrete into the panel. We have run 4 # 3/0 and a #4. The #4 starts out on a ground lug in the meter cabinets to the grounding bushing for that run, and continues with that pipe run to the panel then go's on a grounding bushing there. NOW to my question. Does the #4 get terminated on the the neutral bar and a bonding strap, or does it terminate on a lug on the panel cabinet? I have always terminated this wire on the cabinet as to have an equipment ground. I was told by a peer that this is wrong because the neutral looses it reference to ground when the pipe run turns from heavywall to pvc, and thinks I should be landing it on the neutral bar and bond the nuetral bar to the cabinet. I dont think he's right and I cant really find a code to back him or I up. Any help would be appreciated.

Thanks
Bob

 

[hurk27]

Re: Multi metering Equipment grounding?

You are right the ground should bond to the cabnet and the neutral bar should not be bonded to the ground or cabnet as this would cause a parrell path on the neutral if these units are in pipe then you wouldn't need a grounding bar but if you have run romex then you will need a grounding bar to terminate the egc's to. now the fact that the race-way is not electricly continous does not matter as long as you have pulled a sepreate grounding wire along with the circuit conductors. and kept the grounds sepreate from the neutrals on the sub-panel end. the fault path will be through this ground back to the main service disconect where this ground lands together with the neutral or is bonded with the neutral in some way. this point is also where the gec has to land and the water ground too.