Electrical Ground

[phil_m]

Is it legal, in the city of Los Angeles, to ground to a natural gas pipe, or must it be a cold water pipe?

Thanks

[kactuskid]

Good thing you asked cause it would be EXTREMLY DANGEROUS to ground to a gas pipe anywhere in the world. You need to install a ground to the water pipe, and it needs to be installed within 5 ft of where it enters the home.

[LazyPup]

It would be best to install a driven electrical grounding rod for the house main ground because most underground water service is now installed with plastic materials that do not afford a ground.

In fact, the Plumbing Codes now require that copper water piping must now be bonded to the house electical ground system and it is illegal to connect electrical grounds to the piping system inside the structure.

[mrcaptainbob]

And that reminds me....the first house I purchased (a LONG time ago)Had an old 220 window a/c (reverse heat unit) hard wired to plug fuses. One of the fuses was used for a house circuit. The wire was 14/2. It was draped along those neat pipe 'staples' instead of through the joists. Those staples were holding up the 1" furnace gas feed. And my dad....was a fire marshall from three cities away. When he came by after the closing and walked into the basement.....Well, the sparks that flew weren't FROM the electrical, but BECAUSE of it!

[kactuskid]

quote:In fact, the Plumbing Codes now require that copper water piping must now be bonded to the house electical ground system and it is illegal to connect electrical grounds to the piping system inside the structure.

That's true, all grounds from new circuits run within a structure are required to be run to the main electrical panel. Sorry, my mess up, I assummed the poster was talking about the main ground system.

It is requred per the NEC that "If you have a metal water pipe that is in direct contact with the earth for at least 10’ then you MUST use this metal water pipe as the main grounding electrode, NEC 250.52.A.1 then you must also install a back up grounding electrode listed in NEC 250.52.A.1 through 7 [usually a ground rod] associated with that metal water pipe grounding electrode just in case someone removes that metal water pipe and install a plastic water pipe in its place."

Per: http://www.selfhelpandmore.com/homew...eter/index.htm

[HayZee518]

Lazypup & Kactus - Wanna read something interesting? In Buffalo NY ALL gas piping is bonded to the cold water pipes and hot water pipes in ALL dwellings.

[Rewired]

Yep! Same here in Canada we NOW have to bond the gas to the water, but only the cold water pipe, or right to ground... The reason I heard anyway is all the plastic has piping they are using underground to supply the gas is not allowing for the piping in the houses to be grounded properly.. Apparently someone had all the gas piping in their dwelling get livened up and they got a good shock off of it..
I dunno, thats what I heard and it does seem possible does it not?

A.D

[LazyPup]

It is my understanding that the National Electrical Code will permit grounding the house main electrical service to the water line, if there is a minimum of ten feet of metal piping in direct contact with the earth, and if the electrical bonding connection is made at the point where that water line enters the structure. In my humble opinion the use of piping as a main ground should be discontinued and ALL electrical systems should be grounded directly to a driven ground rod.

In turn, the plumbing codes should be modified to insure that all metal piping within the structure should then be electrically bonded to the house grounding rod as well.

To some this may seem silly, but many fail to consider how many electrically operated devices are directly connected to the piping system, I.E. circulating pumps, boilers, electric water heaters, Water softeners or conditioners, gas furnaces, electric clothes dryers, gas ranges with electrical controls, etc.

Now consider this scenario. Your gas or water supply is replaced with a non-matallic meterial (plastic) and the piping is not bonded to the electrical groundig rod. You then have an electric water heater element or a pump motor fail and it shorts to case ground. Instantly the entire lenght of the exposed metal piping becomes an open exposed electrical conductor.

In theory this would not happen because all the electrical devices should have a ground wire attached, but in the real world many DIY'ers and far tooo many wanna bee tradesmen do not take grounding wires seriously and fail to connect them.

This problem is so prevalent that I personally carry a single probe voltage tester and do not touch a water or gas pipe in a residence until i first test it for the presence of voltage.

The problem can be even more dangerous on gas pipes. Properly one should light a burner then turn the gas off and allow the burner to burn off all residual gas from the shutoff valve to the burner before disconnecting the line, but even then it will only burn off the residual gas until the line pressure equals atmospheric pressure. There is still some residual gas in the line. If there then happens to be a short to ground in the device and you overlook pulling the breaker before serviceing the device, the moment you disconnect the gas line, the gap between the two sections of pipe becomes a spark gap across a gasseous atmosphere.

Examine any 3 prong electrical plug and you will note that the grounding prong is the longest one. That is to insure that the ground is the first wire to make contact and the last one to break contact. It is by no mistake that it is planned that way.

We often see people comment on the posts that they won't be getting an inspection, therefore they are not concerned with code. Please understand, codes are not written to satisfy bureacracy, they are written to insure safety in YOUR HOME.

[HayZee518]

The power supplier here in New York is predominantly Niagara Mohawk Power. It is their requirement that an additional grounding means besides a water pipe ground be installed in ALL service entrances. This additional ground is made up into the meter enclosure NOT to the main panel. The water pipe ground is bonded to the neutral bus in the main panel.
The City of Buffalo requires all metal piping in the dwelling be bonded together irregardless if it is water (hot & cold) and natural gas piping.
Obviously pvc cannot be bonded but everything else metal has to be.

[Rewired]

LazyPup:
I do agree with you about discontinuing the use of a water pipe as a ground to a point because I have seen on more than one occasion in my travels where a grounding conductor / water pipe was carrying several amps of current even with the main switch to the house open!!! Not that its too much of a problem with all the connections good and tight BUT if the connections should go bad I think there is a good chance someone could get "lit" really good..

Funny thing too, you mentioned testing for voltage with one of those single probe testers in a house along the gas and water lines before you touch anything right? I heard that if you go under a high voltage tower with one of those they will light up.... I tried that today, nothing happened but when I got it near the "grounded, and well accessable to the public" tower right beside the worksite, it lit right up!!! ... Not going to be going too near them ones in the park anymore LOL!

A.D

[HayZee518]

Radiated EMF the power companies say is not a problem but like you said, rewired, the tower is hot! Look at how the cables are connected. You have a porcelain stack of insulators - one end is the high voltage, other end is a grounded metal loop - what do you have in between? Think of it -porcelain an insulator, two metal pieces - voila! a capacitor! What do capacitors do? Store an electrical charge! Need I say more?