Back on the job with good news: just got off the phone with the local inspection service co. - squeezed me right in, rough inspection in less than an hour! /forums/images/graemlins/shocked.gif
The bad news: when I explained what I needed, had done, etc., he said that I would need to BOND the neutral and grounds in the subpanel and add aground rod... even with the 4-wire feeder supply to the subpanel. This is EXACTLY what all the hoopla disagreement revolves around in a single circut subpanel application for a detached structure and is supposedly NOT CORRECT. WTH?!!
So, now what do I do? He says he is working off the 1999 NEC, but if the code has changed since and it has been determined that UN-bonded neutral is currently the best way with a 4-wire supply that's what I prefer to do. I told him I would print out the following reference, however, anything else I can discuss or point him to? I only got 20 mins before I head out! H-E-L-P!
Thx
</font><font color="blue" class="small">( per Inspector501 -
( Okay, I decided to post a reply to myself and try to clear up what the NEC® says about running power to a separate building as far as grounding/bonding.
(1) If you only run one branch circuit, and include a grounding conductor, no electrode or neutral bonding is required. But a connection to the neutral is not to be made.
(2) If you run a feeder to the building with no equipment grounding conductor, a grounding electrode must be installed and the neutral bonded to that electrode and the panel enclosure. This is provided you do not have any continous metallic paths back to the main building such as metal water/air lines, etc. And provided you do not have ground fault protection for EQUIPMENT. The average residential property will not have GFPE which is different than a GFCI
(3) If you run a feeder with an equipment grounding conductor, a grounding electrode must be installed at the building and connected to the grounding conductor in the feeder and to the enclosure.
All of this is in NEC® 250.32
)
For reference -
**** NEC ****
Reference NEC 250-32
Buildings or Structures Supplied by a Feeder or Branch Circuit.
This states that two options are allowed for a grounded system.
1) Run an equipment grounding conductor with the supply conductors. DO NOT use the bonding jumper in the electrical panel which ties the neutral (grounded conductor) to the ground.
2) When an equipment grounding conductor is NOT run with the supply conductors, AND no continuous metallic path exists between the systems, AND ground fault protection of equipment has not been installed on the common AC service; THEN, DO USE the bonding jumper at the panel.
**** NEC ****
per johnbilt -
( Note that NEC 250-50 states that all structures and buildings shall have a ground electrode system as described. The issue discussed above is how the bonding jumper is handled. Most residential applications are fed from one panel and therefore this issue is not raised. The neutral is tied to the grounding jumper at the main panel only and provides the required single bonding point. When outbuildings with a new panel are installed, the above issue dealt with in NEC 250-32. ) )</font>