Electrical- Grounding, any cold water pipe OK or needs to be at entrance to house?

Question

Hi,
I have installed a new electrical panel. I have it grounded to the grounding rod, but it also needs a second ground. Can I ground it to any cold water pipe, or does it need to be where the water enters the house? Thanks for your time.

pb4sc

Answer 1

I'm not an electrician, but please, only listen to advice that tells you to ground to a water pipe as well.. I've checked by reference book "The complete guide to home wiring" and it states you should always ground to a metal water pipe - in addition to the grounding rod. It doesn't specify a location, nor does it explain the electrical theory, but it serves to provide an additional pathway for electrical current that is flowing haywire as a result of a short, etc. It, as well as a grounding rod (minimum 8 feet into the earth) will accomodate this power surge to prevent fire, damage, etc...

Also, it makes sense to ground the water pipe nearest the spot where the pipe decends into the ground. If you do so, I'd wrap another copper wire on the pipe before the meter box and position it into the earth. Just another means of drawing the current away from the meter box and potential damage to the meter.

Answer 2

Any cold water pipe as long as you lines are copper (steel is kind of ok), but plastic or PVC pipe will not work. What you are doing is actually grounding the pipes not the electricial panel. The electric Panel should be grounded into the ground using a grounding Rod as you mentioned. But anywhere where PC is in th pipe system you will be breaking the ground for the plumbng system.

Answer 3

You must ground it at the water service AND connect to both sides of the meter. This is your main grounding electrode in the house. Your ground rod is also required, but is a supplementry ground. If you don't have city water you must drive 2 ground rods and bond the copper piping in the house. Just connecting to any cold water pipe isn't the same cause of fittings, distance of pipe,etc. that can cause resistance (ohms) which will not make a solidily grounded connection. #6 for 100 amp and #4 for a 200 amp service

Answer 4

I've just had two properties electric panels upgraded (in NJ).

The 200 Amp service got two 8 ft ground rods (one wire went to both of them). AND they connected another ground to the water pipe where it came into the basement. They also made a bridge/jumper across the water meter and another across the In/Out of the water heater. All passed inspection.

Keep in mind that grounding the water lines has as much to do with preventing your pipes from carrying a floating current, as it does from being a source for earth ground. That's why most ordinances require both. (In the old days they mostly used your water pipes.)

Answer 5

Code requires both a ground rod and metal pipes. It can be attached to the pipe anywhere in the home. Code also reqiures that the nuetral bar and the ground bar are connected inside panel. Most areas now need 2 ground rods to meet code.

Answer 6

NEVER EVER ground you gas pipe. That is a direct code violation. Run a wire from your copper water pipe to your service and tie into the ground bar. If your service feeder wires are size 2 or smaller use a #8, if they are 1 or 1/0 use #6 if 2/0 or 3/0 use #4 size wire. that's per NEC Code 250.66

Answer 7

at the entrance to the house is better cause you might have some plastic pipe intervening. Or if you work on the plumbing you'd wind up disconnecting the ground.

Answer 8

having it grounded to the grounding rod is ok

Answer 9

who said you need two grounds?? if you ground that box to your water pipes, you can get the pooh knocked out of you at the sink one day if something goes wrong.