ECN Forum Forums Code Related Discussion NEC & other Code issues Ground rod required at subpanel?

MX ... I did you wrong ... I must have been inhaling kitty litter fumes last night!

I managed to mangle the question in my mind something awful, confusing 'separating the neutral and ground' with 'driving a ground rod.' Two completely different issues.

If you're feeding a panel, you no longer have a 'single circuit,' you have 'feeders.' A detached building requires an additional ground rod (or other grounding electrode).

And, yes, I'd keep the neutrals and grounds apart

Thanks everyone for the input on this one.. I knew there was some missing info in what I thought and what the inspector is asking for. So a rod it shall be, attached to the ground bus in the subpanel.

Fred, thank you for taking the time to type in that Code reference, that was what I was looking for....

Yoopersup, thank you too. (I really need to spring for an '05 Code book.)

Greg, yeah, that was what I was thinking too, is the telco considered a "metal path" as defined by Code. But I don't quite follow what you mean by this: By "equipment" are you referring to the panel(s) or actual utilization devices?

Roger is of course correct that the coax woukld be a significant path as well. A four wire feeder was in the mix regardless of anything else. Like I'd mentioned, since we have a meter/main where the EGC and neutral is already bonded, it would definately make the panel in the house a subpanel. Offhand, I can't think of any way that one could use a three-wire feeder to the house in this situation. Now if the pumphouse only had a meter pan, then a three-wire feed could be used, with the EGC and neutral bond at the main house, right?

Reno: LOL No problem. I had lost that distinction between a circuit and feeders as used for a detached building.

OT: I'm currently teaching my cat, Gizmo, how to use the toilet. There is a device that makes it easy. After an intitial rebellion (Gizmo hates any kinds of changes) he's doing really good. May be able to throw out litter completely by the end of November.

This is why I love coming here, you guys are all great at helping out!!

When you don't reground the neutral at a remote site you not only see the voltage drop across the neutral feeder you also see the local ground shift between ground and neutral.
If you have something like a PC that uses the EGC as DC ground, connected to something that has a reference to neutral like a TV you will get a lot of hum and you might even let the magic smoke out.

Looking at a job that we have to finish... There is a combination meter socket/disconnect at one end of the lawn that had a 160 foot pipe run that we had to relocate for an addition. It had three lengths of 4/0 that I felt to be too small for the distance and no seperate ground, assuming the meter disconnect to be the actual service. I stepped it up to 3 250's AL and one #3 copper. Would I need rods at the house, and considering what was just said in the previous post, are they going to have that kind of problem if I don't bond the neutral and ground at the panel?

This thread brings up a question I've been pondering for a while.
Assuming no other metal paths between buildings, what method is better. 3 wire or 4 wire feeders? Obviously not paying for or pulling the 4th wire makes sense money wise, but in light of Greg's response it seems better for the end user as well.

And if you didn't reground phone and cable could you still use 3 wire feeders?

If there SEPERATE buildings weither you run 3 or 4 wires a grounding electroide system (Unless) ones there already per code is required.250.32 & 250.50 If 3 wires is allowed bond Neutral if 4 wires required Float the neutral .

I was referring to a separate building with no metal between situation. With grounding electrode systems at each building of course. Or even a remote power pole serving as the service entrance with a sub in the house.
As I understand it you would have the choice NOT to pull the ground with the feeders as long as you reground the neutral at the sub.

My question is what do the people on the forum think is the better system?

I like the four wire system . Then you lose the Neutral ever you still have a equipment ground to trip any hots to ground. Sometimes it becomes a cost issue if your talking long distances with the price of wire now.Going overhead I've never had a problem with 3 wires ,Just the way I look at it I guess.

With no metalic paths I think you are better going 3 wire and regrounding the neutral ... for all the same reasons we ground the neutral at the service in the first place.
Sorry Ryan

Maybe we should go to ground rods at each pole then instead of a equipment ground! Kinda the same thing right!Then bond the neutrals to the poles on 120 volt. ( Just making a point)