ECN Forum Forums General Topics of the Trade General Discussion Area To ground, or not to ground,... that,..is my qwery

... Hi gang, I'm planning on running a 60 amp, 240 volt, single phase feeder out to a detached garage to a sub-panel...my question is... do I need a ground rod out there, or will the bare grounding wire in the SER cable suffice?? I'm using 1-1/4" pvc pipe to go underground, but if I don't use SER, and just pull THHN,..does the grounding conductor then have to be insulated??

Thanx....

Can't quote chapterand verse since I don;t have the book right here, but if you are feeding a panel in a seperate building it must be seperately grounded and since you will be using PVC as a raceway you don't need to pull a ground wire at all. Why would you even consider SER in a raceway?

Feeder, separate building ... need a ground rod.

Whatever method you use, I recommend treating it as a 'sub-panel.' That means having a ground wire back to the main panel, and keeping the neutrals and grounds apart.

While I agree with Reno's interpretation of this issue, around here the inspectors consider a ground wire with the feeder and a seperate ground rod or two to be parallel grounding.

If you didn't rebond the neutral in the far panel your inspectors would be wrong. In fact, in 2008 250.32(B)(2) will be gone and you will be required to run a 4 wire feeder.

250.32 (A) and 250.32(B)(1)(2)
I don't think insulated or not will make a difference on the EGC. I would run an EGC and install a separate ground rod and bond the EGC to it, however, I do not bond the grounded conductor to the grounding bar.

Edward

There is apparently many ideas on how to to this, but the current code is that you run a four feeder and use an insulated ground wire once you leave the main building and go into the ground. And you separate the ground bar and neutral. In our area the the AHJ will tell you to remove the ground rod, paralell path.

You must install a grounding electrode at the structure served! How in the world do these AHJs get around 250.32(A)? An AHJ who makes you remove a ground rod from a structure served by a feeder needs to be re-educated.

I recently fed a detached garage in our area. The local AHJ requires a four-wire feed in addition to two (that's right - two!) 8' ground rods - 6' apart with a #4 copper conductor. The garage is 10' from the house which also has two ground rods in addition to the cold water bond also a #4. That gives me 4 ground rods in a 25' radius plus the cold water bond. All #4.

I'm too lazy to open the book. I believe the egc is necessary if there is any metallic connection to the main structure, such as water pipe , gas, etc. The ground rod IS REQUIRED even if an egc is pulled in.