Whole house grounding

Gentlemen: Re: whole house grounding. Do I have a problem? Was browsing thru earlier posts this thread, then when downstairs to check my grounding. Braid from around the two humongous conductors which go to the two sides of my circuit breaker panel is all bunched together and clamped to my neutral panel. I have a water meter which seems to have a solid metallic body, AND a 3/16ths solid jumper wire around it. Water pipe is apparently galvanized steel, from the main about 150 feet in front of the house. No ground rods anywhere. 200-amp service professionally installed about 21 years ago, replacing previous 50-ampservice. Range connected 220 volts via armored cable about 5/8 inch diameter. Armor on the cable has a short jumper to a water pipe. Water pipe was disconnected from the rest of the system during a remodel at about the same time. I don't see another connection to the plumbing anywhere else, altho ther is a very large clamp on the neutral plate with a fairly large wire going somewhere. Am I adequately (to code) grounded?

 

The 2 basic elements for a Code-compliant system-Grounding installation are a "Primary" Grounding Electrode, and a Grounding Electrode Conductor that "bonds" the Grounded Service Conductor (the Neutral Service Conductor) to the "Primary" Grounding Electrode.

With a 200-amp Service the Grounding Electrode Conductor is probably a bare,stranded, #4 copper conductor that at one end terminates on the Neutral terminal-bar in the Service-panel, and at the other end is clamped to the Grounding Electrode.

If your under-ground water-service line is metallic, then it's probably the "Primary" Grounding Electrode and the GEC should be clamped to the W-S line as close as possible to the "point-of-entrance" of the W-S line. If there's a water-meter, there should be a "jumper" across the W-M so that the interior water-lines remain Grounded should the W-M be removed.

 

Sounds compliant for 21 years ago. You are NOT required to update when the code changes. The old installation is grand fathered.
The only significant changes that have occurred are that the water pipe must be bonded within 5 feet of entering if it is the primary electrode, and a supplemental grounding electrode is know required with less than 25 ohms (check the number) resistance or a second electrode is needed. Since electrodes are usually cheaper than testing, most people just put in two electrodes and skip the test.
I would consider connecting the armored cable jumper directly to the ground bar in the panel to prevent any chance of loosing the connection.

 

PATTBAA & brickeyee; thanks for your replies, they're very helpful. Since the installation was professional I suspected that the grounding was OK for the time. ( Sadly, the contractor and all his family except one son were killed in a car accident shortly after finishing my job.)
How mandatory is the "5 feet from the water service entrance?" does the grandfathering cover me; and should I perhaps be adding a ground wire from my breaker box to the water pipe. Its a distance of about 30 feet as the crow flies. Would I gain anything, or maybe not worth the effort.
I have three armored cables from my breaker box. One, a big one, described above, is for the range. A second, smaller, goes to the oil heater for the Beckitt(sp?) burner. A third supplies two fixtures and an outlet. I suspect that that it was just whatever the original electrician had left in the truck. It was a part of the housethat was an attached garage, later converted toa kitchen.They are all clamped to the box, but I don't know if the box id, or should be, grounded. Any thoughts?

 

Look for a bonding jumper from the nuetral/grounding bar to the box. It is usually a short copper piece that goes under set screw in the bar and under another screw into the back of the box. As long as that connaection is secure the box is grounded and the cable clamps holding the AC will ground the armor. I have found less than tight cable clamps on AC (inside crown nuts and outside set screws) and make a habbit of checking old ones the first time I work in a box.
Everything is grandfathered if it was compliant at installation time. As long as the pipe has not had any plastic sections inserted it is fine.

 

Thanks brickeyee. I just went and looked for that jumper; couldn't see one but with my RadioShack digital multimeter measured 1.1 ohms between the neutral plate and the box, so I guess it's a safe bet that the two are bonded. Now, I just noticed that an old, large (>12guage?) wire clamped to the grounding/neutral plate goes into a looong length of black iron pipe(conduit?) about 30 feet into a corner of the basement diagonally opposite the water service entrance (i.e. about 60-70 feet away as the water pipe goes) and is clamped to a copper pipe there. Said copper pipe is connected to the water supply continuously, but at a considerable distance. The conduit itself has a jumper to the same water pipe. The nearby range supply armored cable is connected to the butt end of some piping which was cut off from the rest of the system, as I mentioned before. The other end of the AC is clamped at the box, so I guess it's grounded OK. See any problems there? Also I think I need a better clamp at the end of that long groound wire if it is so crucial a connection.

 

The presence of black-enamel steel conduit suggests that it enclosed the Grounding Conductor for the "original" Service, which since has been re-placed by the existing Service.

"A better clamp at the end of the 'long' Ground wire."----Please be more specific in you description---at what points does this "long Ground wire" connect.

Please peruse my previous "Posting".

 

Pattbaa. I just went and checked those connections. A length of #12 fiber-wrapped wire is clamped with a large clamp integral with the grounding/neutral plate in the breaker box. It leaves the box and disappears into aforementioned black enameled conduit. It reappears at the other end of the conduit about 30 feet away for about a foot and is clamped with a heavy clamp to a copper water pipe over my laundry tubs. A short length of the same wire is "clamped" to the conduit with a piece of strap iron(the kind with holes spaced down the middle) rather loosely. Close by is the large armored cable for the range. It has a similar jumper clamped to it, but the other end of this jumper is rather sloppily "clamped" to the same water pipe with, again, another piece of strap iron. This "clamp" wiggles when I move it. Just don't know how important it is; just seems like very poor practice. (I was wrong when I said that a piece of disconnected plumbing was involved in an earlier post.) Thanks again for your help.

 

I would replace the #12 with #6 copper, if mechanical protection pipe has bends, use stranded. The clamps need to be mechanically tight, else no protection. The perforated strap is a make- do; replace it with a grounding bushing. In other words, the intent was good, workmanship poor.