I work with a Journeyman Electrician and about 2 weeks ago he installed 2 #4 Solid Grounding Conductors on the same Ground Rod. He ran one to the meter bonding screw and the other to the 150A load center inside the home. Can this be done or is it a code violation?
If the #4 is bonding the nuetral in the subpanel I would say it is a violation of 250.24. I don't have my NEC here, but two other things come to mind: 1) If it doesn't bond the nuetral in the sub panel, then isn't it an equipment grounding conductor? If so I believe it must be in the same raceway/cable. 2) If it is an e.g.c. you can't go directly to the earth.
Bennie, since you have some interest in magnetic fields, consider this: the GECs to the panel and to the meter allow neutral from the house loads to split and some goes to the meter by the GECs and some by the neutral.
This sets up identical net current fields along the path of the GECs and also the cable to the panel. If the meter is close to the panel, a very short path, no big deal. If it is outside and around the corner, one part of the building now has a high field. Put a child's bedroom there and you connect with the leukemnia statistics.
This is similar to the situation Mike Holt keeps emphasizing where a separately derived system has the N/G bond at the transformer and also at the panel. It should be one or the other. (And don't go ballistic just because I used those nasty words, "separately derived")!
I don't mean to put pressure on you... Where is a drawing? Please
The way I see this particular installation, it is creating an 'electrical path' for parallel current flow. One or the other should be removed, depending on what the POCO requires.
Is not neutral current going to travel on the GEC from the panel to the ground rod and then from the ground rod to the meterpan as the current tries to get back to it's source?
I still ask "what is the problem with parallel paths for neutral current?"
Parallel paths have been around since the neutrals were earthed.
The MGN utility system is high in net current carrying conductors. Magnetic fields are apparently OK outdoors.(I don't believe it)but the authorities of science seem to approve.
The only system that will not have parallel neutral paths is a isolated secondary winding.
As far as my raising a fuss over the separately derived system issue, I am going to propose to the NEC that technical committe action change the definition of a separately derived system to; A transformer or generator that supplies a wiring system.
Retract the part that refers to a separately derived system being a premises wiring system with no exterior connections.