Grounding a Single Family Dwelling

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horrorsix

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Harrisburg PA
I'm upgrading a single family ranch house from 100A to 200A. Normally I ground to two locations. first is with in 5' of where the water pipe comes into the house. and second is an outside ground rod.
This particular house I'm working at now it will be very difficult to run a ground wire from the panel box the the water pipe entrance.

My questions are- Is two points of grounding required and can I use two ground rods 6' apart?
 
250.50 Grounding Electrode System.
All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used.
 
horrorsix said:
I'm upgrading a single family ranch house from 100A to 200A. Normally I ground to two locations. first is with in 5' of where the water pipe comes into the house. and second is an outside ground rod.
This particular house I'm working at now it will be very difficult to run a ground wire from the panel box the the water pipe entrance.

My questions are- Is two points of grounding required and can I use two ground rods 6' apart?
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Sorry. Just because it is difficult does not relieve you of its requirements.

BTW To everyone else. 'If' the ground rod is within 6' of the metal waterline does it fail? Remember it is driven in the ground.
 
jxofaltrds said:
BTW To everyone else. 'If' the ground rod is within 6' of the metal waterline does it fail? Remember it is driven in the ground.
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I would not say it "failed", it can be there, but it would not count as a second electrode per 250.53(B)
 
jxofaltrds said:
Sorry. Just because it is difficult does not relieve you of its requirements.
Click to expand...

I agree. :)

BTW To everyone else. 'If' the ground rod is within 6' of the metal waterline does it fail? Remember it is driven in the ground.
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Not per 250.53(B) as your example has only one grounding system.

Not per 250.56 as that does not include water pipes.

If they have to drive a second rod per 250.56 the second rod would have to be at least 6' from the first.
 
You are correct... I thought I had learned something new :)
after I saw the "master's" post, I said opps, I reread that section and caught my wrror, but it was too late...
I was patiently awaiting your correction.:grin:
I will try to read more closely.
 
Have the plumber run 10 foot of the metal water line buried with no plastic wrap near the service to accomidate you. For instance like a pop up to a spigot. Connect to it like how you did your ground rod connection- on the exterior at the spigot. Then go read 250.52.
 
The OP never stated if the pipe coming in from outside is metal in contact with earth for 10' or more. If it isn't, then you are only bonding the pipe and not grounding it. If just bonding it, you can connect anywhere on the pipe system -- does not have to be within 5' of where the pipe enters the house. Strangely, you still have to use a conductor sized per 250.66 when just bonding the pipe.

If the pipe is metal in the earth, you could have a plumber (or yourself) dig it up and insert a polyethylene section so you don't have 10' in contact with the earth where it leaves the house.

You're most likely going to need 2 ground rods regardless, unless you can prove that just one is 25 ohms or less. A water pipe ground doesn't help much with code compliance -- only causes you more headaches. But, it can work well if it is metal all the way out to the street.
 
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