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Uncle Monster[_2_] Uncle Monster[_2_] is offline
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Default Grounding wire for house. Is this right?

On Wednesday, December 9, 2015 at 10:20:34 AM UTC-6, wrote:
On Tue, 8 Dec 2015 21:34:32 -0800 (PST), wrote:

My 1950s era house had a 100amp panel, with a grounding wire that ran to my well and was clamped to the well casing. I hired a licensed electrician to upgrade to 200amp panel. He also installed 2-3 ground rods outside the house and connected from the new panel to them, AS WELL AS running from the panel via a heavy wire (looks like #6 aluminum strand) clamped to the copper water pipe downstream of my pressure tank. Notice... he didn't connect to the well casing, but to the piping on the "house" side of the pressure tank, and the pressure tank is separated from the well casing by my pump and black rubber hose (i.e. no electrical continuity). And he left the original ground wire as-is on the well casing.

Never noticed all this until recently.
Is this correct?
Shouldn't there be a jumper cable to connect across the black rubber hose (from the copper pipes to the well casing?)

Just curious
Experienced advice appreciated.
Thanks
Theodore.


The well casing is an available electrode and it most be used. The
Grounding Electrode Conductor to water pipes is sized by 250.66 and
should be #4 for your typical 200a service. Since made electrodes like
ground rods are not really that effective, you only need #6, no matter
what the service is. The wire to the isolated interior water pipe is
only bonding the pipe, you should be bonding to the house side of the
plastic so jumper around the water softener.


I'm surprised at the #6 to a ground rod since the inspectors around here always insisted on a #4 to ground rod and water line for any residential service. On the last service entrance I put in a business, the inspector also required grounding bushings on the conduit nipple between the meter box and main breaker enclosure. The city engineering department often requires things that are stricter or over and above that which is in the NEC. I have installed dielectric unions when joining galvanized to copper water pipe then ground clamps on the pipes with a #4 jumper around the dielectric union. The electrical inspection department here is fond of #4 grounding conductors on everything related to power for residential and light commercial. For telecom and cable systems #14 to #10 in homes but usually #6 to the telecom system backboard ground bars in business and industrial locations. From what I remember for backboard ground bars a #6 grounding conductor to the nearest power system ground using a separate ground clamp without any coiling of the wire and as straight as the wire can be run. I recall the wire size and direct route has to do with keeping the impedance and resistance of the grounding conductor as low as possible. It's been a while since I've installed a service entrance so I'm not up to speed on any changes the city electrical inspectors want to see but I always had to satisfy them since they had the final say.¯\_(ツ)_/¯

[8~{} Uncle Power Monster