What is NEC Code For This Grounding Scheme ?

[John Ross]

Quick recap: 1960 house, crawlspace, 2 wire romex, grounds only run to baths and kitchen, galvanized water pipe to street was used for grounding (NO ground rod).

I want to ground 2 or 3 outlets and discussed going to a water pipe method here. Everyone mentioned the "5 foot rule" per NEC. Some were concerned about the ground not tripping the breaker. I have had nothing but problems finding a good electrician in my town!!! I think I finally did and want input on his plan.

Talking on the phone, he proposed the following and said it would pass code (local):

1. Drive 8 foot ground rod and connect to panel.
2. From desired ungrounded receptacle(s) go through floor to crawlspace with ground wire and run back to panel.
3. One receptacle is for pc, and he suggested doing same method, but use new wire and make it a dedicated circuit so there would be no interference or something with pc. Not sure if this is necessary?

In doing the above, how specifically should it be done to meet NEC?

If I understand, it will still need to be bonded to the water pipe. Should that be within 5 foot of water entrance point? And can you bond it to more than one place (i.e. to the 5 foot and also close to panel?). I'm still not up to speed on this bonding concept, hence the question.

Is there a specific way of doing it so that it will ensure that it trips the breaker? Do the grounds go IN the panel or are they attached to ground rod (assuming ground rod is attached to panel). Does it matter?

At what point (if any) can the ground wires be combined into one? I seem to remember something about you couldn't use a junction box-- everyone had to have a home run. I just don't understand enough about this to know where that home run ends?

Not sure if this is relate to the above, but he did mention something about "looping" the grounds--but I am not sure where he meant that or what it means.

Hopefully, that is a good enough description that you can not only answer questions, but raise any issues that you forsee (as you can tell, I am not too up on electrical).

-- John

[Pete C.]

Not getting into the NEC, but if you have access via a crawl space to drop new ground wires down from the receptacles in question and run them back to the panel, I'd simply run a complete new wire (romex 12/2 w/ground) and be done with it. The extra cost of the wire is piddly compared to the labor required to run it, which should be about the same whether it's running a single conductor or a full cable. If / when you sell the place in the future, an add-on ground along side old two conductor romex is likely to raise questions with any home inspectors / buyers even if it's to code, vs. clean new runs of modern grounded romex.

[RBM]

Once the ground rod is driven and connected to the buss in the panel, it also becomes attached to the existing water pipe ground which also runs to the buss in the panel. The individual ground conductor can be attached to any point along the grounding electrode system. The most practical location is probably the panel. IMO running ground conductors to non grounded outlets looks Rube Goldberg, if it's not to dificult, I would run new cables to these outlets, gang a few together in a jbox then run a line back to the panel

[Bill]

The approval for any electrical work is up to your local electrical inspector. They usually have office hours and will answer questions. Take plenty of pictures so the inspector can see what is what. (pictures of house, outlets, electrical panels, existing grounding, etc.)

In my case I was required to install two grounds rods 6 ft. apart and run a ground wire from these to the panel. And install a cold water pipe ground and run this via a separate ground wire to the panel. Also to connect a ground wire from the cold water pipe to the hot water pipe on the water heater.

My ground system is good. If one ground wire gets broken or disconnected (quite common actually), there is another ground wire and ground. Also there is a "central point of ground", that being at the main electrical panel.

Once you get a good grounding system, then run new romex wires with ground to outlets you want grounds on. Installing a separate 20 amp outlet on its own breaker for the computer is a good idea.

[HeyBub]

Running a separate circuit (including ground) to a dedicated outlet with its own breaker is the best idea.

Think of the water pipes as a potential source of power - that's why they are grounded. The water pipes are not the SOURCE of a ground for the electrical system - grounding pipes protects you when you come into contact with the plumbing.

[gfretwell]

You can use a single equipment grounding conductor for several circuits as long as it is sized to the biggest one. I have seen people run one #8 solid as a bus and use split bolts to pick up grounding pigtails from the various circuits along the way. The code is really pretty ambiguous about wiring methods when you are adding an EGC to a circuit that doesn't have one. As long as you are getting back to the main bonding jumper with your ground (the bus in the panel) in a solidly connected way you should be OK.

[RBM]

[John Ross]

Clarifiation: The wiring does not run in the crawlspace, so you would not have a new ground running along side old 2 wire romex. Obviously, if it was like that I can see your point.

The crawlspace is only being used so we don't have to tear up the walls and rewire the whole house.

-- John

[John Ross]

I may have not made this clear, but the original wiring is NOT run in the crawlspace. The idea is to drill a hole up through the floor and bring the ground from receptacle down to crawlspace and then over to panel.

I assume in this situation you could not just run a new romex to each one unless it was dedicated?

As far as being connected to the water pipe. My understanding is that back then they just connected it to the closest pipe to the panel. So what I was asking is if the pipe connection should be connected closer to the water entrance point of the house (which is the opposite side of the house)?

Also, can you explain what he meant by "looping the grounds?" Any search on that term brings up very negative things so I am not sure if I have it in the right context.

thanks,

-- John

[John Ross]

I was more concerned with the possibility of having the grounds run to to a junction box, then have a single ground come out of that and then have THAT connect to the panel. I saw someone say that the NEC for this type of retrofit implies that each ground has to make a home run?

The other thing is that someone brought up something about creating a magnetic loop (not sure if that is correct term) and implied that could be a big problem in that it would raise resistance in the grounds wires.

thanks

[John Ross]

This is what I was getting at. Should the connection to the water pipe be moved to within 5 feet of the entrance of the house (to be closer to that 10 foot of pipe you refer to).And also does it matter if the old connection is left (i.e. 2 places it is bonded at)?

-- John

[John Ross]

This is what I was getting at. Should the connection to the water pipe be moved to within 5 feet of the entrance of the house (to be closer to that 10 foot of pipe you refer to).And also does it matter if the old connection is left (i.e. 2 places it is bonded at)?

-- John

[hallerb]

new bonded ground should be right where pipe leaves home.

how many AMPS is the main panel? 60? I would start by replacing the main panel and service drop. Is your fuses?

[John Ross]

What was your original system?

The hot water heater connection is a good idea. I am going to do that no matter what else.

-- John

[John Ross]

100 amps and breaker box. NO budget to upgrade that--I just want 2 grounded outlets!

As far as the new bonded ground being right where pipe leaves home, is it ok to have one also farther away (i.e. original one)?

-- John

[zxcvbob]

I've grounded about a half dozen old outlets in my house.

I drill a tiny hole in the wall plate with a 54" long drill bit and fished a green wire, then made a home run to the breaker panel. I used a big split bolt connector to connect the new grounding wires to the big Ground Electrode Conductor close to where it came out of the panel.

Bob

[RBM]

The only part of the water main pipe into your house that can be used as a grounding electrode is the first five feet from the point of entrance. A ground conductor attaches to the pipe and runs to the ground buss in your main service panel. In addition to that electrode, essentially two driven ground rods are required. They get driven six feet apart and another conductor is connected to them and run back to the ground buss in the main service panel, effectively bonding these rods to the service equipment and the water pipe. Looping is probably someone's expression for bonding

[RBM]

Yes, move it and leave the existing connection alone

[Bill]

My original grounding system was no ground at all, an old rusted fuse box, and all sorts of other nasty stuff in an 80 year old house...

[Pete C.]

My point is that if you have access to the crawl space you can run new

12/2 w/ground romex to the receptacle locations and install new grounded receptacles. The existing ungrounded wiring can simply be cut back and abandoned in place in the walls (disconnected from power sources of course).

I was looking at purchasing the house and found the separate ground addition, I would be factoring in my cost to strip it out and replace it "correctly" into any offer I made. Code compliance has no relevance in such buyer decisions and even if the additional ground installation is

100% code compliant, a potential buyer is under no obligation to accept it.

I know not every home maintenance decision should be based on future sales worthiness, but the point here is that the material and labor difference between doing the job in a manner likely to put off future buyers, and doing the job in a more acceptable manner is relatively small.