Grounding Electrode Conductor Bonding

[mdshunk]

I know that when I'm using an underground water pipe as a grounding electrode, I have to jumper over the water meter if there is one inside the house. Do I also have to jumper around one of those cartridge filter housings (PVC)? Water softeners? Water heaters? I did a service today where the customer had a water filter installed in the first 2 feet of water pipe inside the basement and no water meter. I jumpered around the water filter anyhow (just as I would a meter). I didn't know for sure if I had to, but I figured for the price of an extra water pipe ground clamp and no extra time, it fell into the "good idea" category anyhow. How much of the metal piping system inside the house do I have to look over for things that could be removed and/or PVC items in the metal water piping system?

[Speedy Petey]

You did the right thing. :) 250.53(D)(1) states these items must not be relied upon to give continuity for the purposes of grounding or bonding.

[mdshunk]

Okay, then what I'm trying to get pinned down... do I have to scour the entire interior metal piping system of every service upgrade and jumper everything nonmetallic and/or removable?

[Speedy Petey]

Wellll......You may want to give a quick check. Any of these silly plastic filters break the water piping bond, unless they are piped around with a bypass valve.
Most are near the incoming water line or else they would not be very useful.

[suemarkp]

Doesn't the code say all interior metallic pipe that could become energized must be bonded with a conductor sized per 250.122 using the amp rating of the circuit that could energize it? One bond to the cold water service sized per 250.66 can't be avoided.

If so, then little piping would need to be bonded in most houses. I can see the water heater as a likely energizer, but that circuit should have a grounding wire bonding the tank. If by a leap, the circuit wire could energize the hot pipe and there are dielectric unions, then I can see bonding the hot pipe. This seems to always be done, but yet the case seems weak to me.

I don't know how all these little pipe stubs that get isolated by filters and stuff could become energized. If you have electrical devices attached to those stubs, then extra bonding would be a good idea.

If the pipe is being used as a grounding electrode, then I'd say yes you must bond between every non-conductor between the bonding connection and where the pipe enters/exits the building to the earth. There shouldn't be much here, since this connection must be made within the first 5 feet of entering the building.

If the outside pipe is plastic, I don't see why you'd need to jump non-conductors in the cold water piping. Guess it really comes down to the inspectors definition of what bonding the "cold water piping" means -- every segment of cold water pipe, or just the main segment.

[Wgoodrich]

Only that metal pipe from entry to 5' within the building may be used as a grounding electrode connection.

With or without the metal pipe in direct contact with the earth the entire metal plumbing inside the house must be bonded to prevent shock from water pipes. Only exception is short sections of metal pipes such as metal fill tubes.

The house that has water pipe in contact with the earth must be used as the primary grounding is avaialable. However the rest of the pipiing in the house is also bonded at the same time if no plastic or meters are involved. If the plastic or meters are involved then you must jumper those sections breaking the electrical bonding path with or without contact with earth.

Hope this helps

Wg

[Frank]

We're on a well (submerged pump entering the house using plastic pipe) which changes to copper as it comes out of the pressure tank. Should this system be bonded also? Hot water heating is by oil furnace i.e. not sure how it could become energized, or does this even matter?

thanks

[mdshunk]

When the water enters the house by poly pipe, you should bond this pipe with 1/4" od poly tubing instead of #4 copper.

{This is just a joke, but I did see one time that someone had used bond bushings in a junction box with all SCH40 PVC conduits entering it. I wished I had owned a digital camera at that time. That picture would have been added to my file of weird stuff I've found on jobs. Go figure}

[Speedy Petey]

The water piping system should always be bonded.
Like WG stated, if the pipe coming in is metal it must be used as the primary "grounding electrode". It then must be supplemented by a ground rod.

[Frank]

mdshunk - thanks for your advice. I decided to use the new "glow in the dark" shoelaces which are a better grade of plastic; supposedly they are a bit stronger than the poly tubing you described - and a lot easier to install too ;)

[Wgoodrich]

Speedy Pete, glad one person is still with sound mind.

Frank, mdshunk, you two are starting to make me think you have spent too much time sun bathing is the artic circle.

Just having fun

Wg