Sub panel ground

[cslye]

So I have used the search function here and google and have hit analysis paralysis I think...

Building a detached garage in California, with a permit and work being done by licensed GC.

The GC has completed the electrical feed wiring and is looking for payment for that piece. (100 amp panel with disconnect installed and fed from primary panel)

I was taking a look at the work and noticed there is no ground wire from the primary panel to the sub panel. There are 3 wires only, the under ground portion is in non metallic conduit, exiting the primary structure running to the sub. There is a ground wire that was placed into the foundation which is run into the sub. There is also telephone lines and coax cable line in a separate NMT running between the buildings.

My question is, is this the correct wiring (no ECG bond between primary panel and sub).

Correct meaning :
1. By code (I can make him pay to fix)
or
2. Best practice, whats safe for my family (I pay for fix)

Thanks

 

[shamrock12]

Under current code cycle, the contractor should have pulled a 4-wire feeder in which one of them would be the equipment grounding conductor. Neutral and grounding will need to be separate. The detached garage also need a grounding electrode system but it sounds like your contractor has already taken care of that by bonding to the foundation rebars, right?

Up until the 2008 code, what the contractor did would have been legal. Under the pre-2008 code, a 3-wire subfeed to a detached building would have the neutral and grounding bonded at the subpanel.

Here is a picture (on the right) showing how it should be done under the current cycle.

 

[cslye]

Thank you for the clear answer. If that was put in 2008, and California follows 2010 standards I guess I will be asking to get that fixed.

Thanks again

 

[wyliesdiesels]

Thank you for the clear answer. If that was put in 2008, and California follows 2010 standards I guess I will be asking to get that fixed.

Thanks again

Yes, have him change it to a 4-wire feed. And code cycles are every 3 years. California will be adopting NEC 2011 in Jan 2014...