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cuemaker
09-24-2006, 03:17 PM
My father in law is remodeling his bathroom. As part of the remodel he wants to install a new electrical box and wire the bathroom to it. As he remodels the house, he will add each room to the new box.

The question is he was told that he needs to ground the box in 2 places. To the ground and to a water pipe. All his water pipe is plastic except for the well casing (and it would be a serious effort to get to that).

Is it true he needs to ground it 2 places? And if so any other ideas on how or where to ground.

Thanks guys.

HWooldridge
09-24-2006, 08:03 PM
Nobody wants to answer this for the liability exposure...;-)

Get a licensed electrician to do it. I am not an electrician nor do I play one on TV but I assume the dual ground suggestion is for backup in case one fails.

cuemaker
09-24-2006, 08:16 PM
Well darn, I am not going to hold anybody's feet to the fire.....

LarryinLV
09-24-2006, 08:19 PM
Cue,

I suspect that your father has been given erroneous advice. By your statement one would presume he is planning to install a subpanel and feed this panel from the main panel. If this is the case, generally a subpanel would have the neutral and the ground separate, (not bonded), and those wires, plus line would go pack to the main panel where they would be properly bonded and grounded. You do not normally want another ground in the system. Since this is a bathroom the plumbing must be installed so it cannot become energized.

A separate structure from the main, such as a detached shop, would require it's own ground, perhaps two.

Bathrooms have a whole section pertaining to them for bonding, GFCI protection, and amp loading in the NEC.

He must check local codes and not rely on advice by non-qualified persons. If in doubt, consult a professional or ask the local building inspector.

Weston Bye
09-24-2006, 08:36 PM
I just built and wired my own house. The code required connecting the main panel to two or more ground rods, depending on local conditions, and to the water system. I had to run a #8 bare stranded copper wire about 40' to where the water meter was. I also had to connect another piece from one side of the meter to the other, as the meter was not considered a good ground path. Same thing for the water heater, from the hot side to the cold side. Oh, also had to ground the natural gas piping the same way.

About the only two places I can think of for your ground to the water system would be the water heater and the well casing. If you have a submersible pump, the grounded casing might be a good idea, as it will help protect the pump in the event of a lightning strike. That being said, the submersible pump in my previous house has survived 25 years with several nearby strikes without injury.

If the water heater is your only option, be sure to connect to the cold side, and jumper to the hot side also. However, consult your local electrician or electrical inspector.

CCWKen
09-24-2006, 09:03 PM
The requirements may vary by State, County and City. Putting a jumper from cold to hot supply made of plastic is a silly and useless suggestion. :rolleyes:

Your best bet it to check with an electrician that does work in your area.

J Tiers
09-24-2006, 09:20 PM
And, grounding in any way to the gas piping is USUALLY considered forbidden.

I don't know of anywhere that is allowed, let alone recommended. But I surely don't know everything.

Usually both pipe and ground rod are required now. Used to be pipe, since that was the best ground, being connected to everytone's house. And it worked...

We had the neutral oipen for 10 days, pulled off by a tree linb. Electric company was too busy to take care of it, but there was never a problem, since our neighbor's neutrals in their drops were carrying our load. I know, I had a clamp-on on our pipe.

Surprisingly, after the wire was fixed, it only dropped the pipe current by about half.

In any case, I assume he is putting in a new service, and moving stuff over to it gradually.

That leads to a question as to which "service" is live now, and from where. If it is a subpanel NOW, it can't be "bonded" neutral to ground until it becomes the main service.

And, one wonders what the grounding is now on the existing service, and why it isn't OK to use.

Sounds like local advice is needed...... get an electrician. Not because we don't know, or he cant do it, but because we can't see this lashup to understand what we are advising about............

Herm Williams
09-24-2006, 09:48 PM
When I wired mine in Miss I called the power co and they sent me a written instruction sheet so there would be no misunderstanding. Ground to the subpanel in addition to the neutral from the main panel. The instructions stated the ground, neutral, and hot wire size and color.
re

Carld
09-24-2006, 10:14 PM
cuemaker, go ask the local electrical inspector AND the power co. Many times they do not agree with each other and if you go against the power co. they can and will turn off your service. The power co. rules apply from the pole to your breaker box. The county and state code applies from your breaker box through the house, shop and or garage. I don't think that you can have two panels and do what you are describing. You may have to remove the old panel and replace it with the new panel. I hope your father-in-law is doing this with a permit. Taping into the supply side of an existing panel is dangerous if he don't pull the meter. If he pulls the meter without the electric co. involved they can fine him and or shut off his service.

Jim Hubbell
09-25-2006, 05:22 AM
In No. Idaho a ground rod is required to be connected to the nat. gas piping system.
Is this not required elsewhere?

Weston Bye
09-25-2006, 07:08 AM
And, grounding in any way to the gas piping is USUALLY considered forbidden.

The NEC (national electrical code) forbids the use of a gas pipe as a grounding electrode. However, the code requires metal lines to be bonded to the house grounding system. This is usually considered good practice for any metallic system or structure in the house; metal furnace ducts, metal framing, even the garage door tracks, and don't forget your compressed air system, but may not be required by code.

In the past the water system was considered the best grounding system. Not any more. Ground rods must be the primary ground. Two or more rods, 6' apart is now code. In very dry soil, special systems may be required.

My thoughts about grounding the water heater in a plastic water supply has more to do with bonding and leakage current through the water if the water has sufficient mineral content to make it conductive - probably overkill, and not necessary.

dicks42000
09-25-2006, 10:13 AM
Wes;
Thanks for posting an independent confirmation about ground bonding of gas piping. J Tiers pointed it out in a thread I posted to a few weeks ago in reply to my post.
I bond the gas piping and plumbing on new furn. & H/W tank installations I do.
Aside from the inspector, there are several reasons, some you have alluded to re plastic piping & mineralized, conductive water. Regardless, most underground gas piping in BC is now plastic but the house piping is copper or steel. Meters may have di-electric unions and the gas appliances probably have some electrical/ electronic component. Would you depend on sketchy building wiring for the only ground path ? Hmmm.
Ever got a shock when replacing a Pressure Reducing Valve ? (Somebody already mentioned ground currents when the neutral was disconnected.)
Also furnaces & water heaters often sit on wet concrete floors (conductive, partial ground). What about electric water heaters with di-electric unions or nipples.
I guess I don't like becoming electrically energized. I'll bond when required.

Evan
09-25-2006, 11:51 AM
In No. Idaho a ground rod is required to be connected to the nat. gas piping system.
Is this not required elsewhere?

The natural gas system here is all plastic including the mains and all distribution lines right up to a coupling in the ground below the meter. When they bury the lines they string a tracer wire with them so it can be energized with a signal generator to find them later.

Weston Bye
09-25-2006, 12:37 PM
The natural gas system here is all plastic including the mains and all distribution lines right up to a coupling in the ground below the meter. When they bury the lines they string a tracer wire with them so it can be energized with a signal generator to find them later.

It is just as Evan describes with my gas service, the tracer wire is connected to nothing - just wrapped around the plastic pipe just below the meter. Nonetheless, the black pipe gas distribution inside my house is bonded to the electrical system.

J Tiers
09-25-2006, 01:08 PM
The NEC (national electrical code) forbids the use of a gas pipe as a grounding electrode. However, the code requires metal lines to be bonded to the house grounding system. This is usually considered good practice for any metallic system or structure in the house; metal furnace ducts, metal framing, even the garage door tracks, and don't forget your compressed air system, but may not be required by code.

In the past the water system was considered the best grounding system. Not any more. Ground rods must be the primary ground. Two or more rods, 6' apart is now code. In very dry soil, special systems may be required.

My thoughts about grounding the water heater in a plastic water supply has more to do with bonding and leakage current through the water if the water has sufficient mineral content to make it conductive - probably overkill, and not necessary.

Of course, bonding to the gas line is exactly equivalent to making it (part of) the grounding system..... so there is a conflict of sorts....

One of the issues bonding or grounding via gas lines is the possibility of encouraging corrosion, which can end up leaking gas into your house and blowing you up one fine day (gas follows the pipe path and leaks in around the pipe entrance). There have been two of those in one week here, although the causes are not certainly grounding-related corrosion. While AC normally does not do that, ground contact may form a rectifier.

A good "bond" may be low enough resistance to pass quite a bit of current into the gas pipe, and cause corrosion.

As for bonding, (per the code copy I have handy, not the absolute latest) the bonding is required for piping etc "which may become energized". And, the equipment grounding conductor for the equipment which may energize the piping etc is acceptable as the bond.

So, your stove with its clock and electric ignition (I hate those) "might energize" the gas pipe, but its cord is an acceptable bond.

Ditto for furnace and its EGC in the supply wiring. Should satisfy that requirement just fine, and already exists.

You don't need a separate bond in that case, depending on your definition of "which may become energized"....... if you string that out to include "an uninsulated service conductor might fall on it", then you need full size bonding equal to the main EGC to the rod or pipe. but that is only "reasonable" in the mind of the most peculiar local inspector (who you must obey even so....I'd have him write it down and sign it).

And, BTW, a freaking forest of ground rods is far less effective than one good water pipe ground.... since it connects you in parallel with all your neighbors grounds too.... The allowable 25 ohms (or 2 rods regardless) may easily allow your entire ground system to be 100V above actual earth potential.

Edit: I agree on the method sunding dicey. As I mentioned before I still don't see how your FIL is doing the deal..... either he has two "services", or he is doing something else that does not sound quite right.

What SHOULD be done is to have the box replaced as a whole. Then the branch circuits can be upgraded as the work goes along. Old non-grounded wiring can be hooked up to the new box fine..... it was done just before we bought our place, part of the city requirements.