Grounding wire question

[Richard]

Went to Home Depot other day to get couple filters for whole house filter. When I got in the area..I noticed the softners display. Saw a mockup display of water "path" from pipe into house, though each step. When I saw the whole house filter, I noticed they had a grounding wire grounding from each side of the water line to the filter. In other words, the plastic filter housing broke the continuity of the copper, so they grounded each side of copper to the other with a grounding wire bolted on. As I was then unable to find anyone who really seemed to know anything.. I decided to post that here..

I do NOT have my (self installed) filter grounded like that. I simply installed my filter in line.. As I was looking at display, I failed to see WHY it's needed. After all, won't the water in the line/housing ITSELF act as a bridge to ground any current this wire might theoritically bridge? I know the $$ are few, but the cynic in me saw this as simply marketing. But then..what do I know! (about marketing /w3tcompact/icons/grin.gif )

So..any merit in putting grounding strap from one side of the connection to the other? Easy, cheap to do..but necessary? (or wise)

Richard

 

[Inspector507]

Richard,
Always install a wire around any plastic "interuption" of your houses metal pipes. All metal water pipes in the house need to be connected to the ground of your electric supply. That even includes the dielectric unions/nipples on your hot water heater. Water will not carry fault current like metal water pipes will. If you have 10' of metal water line underground, that should be the ground for your electric system. If you have plastic underground and metal inside, they still need bonded to the ground for safety.

 

[Lane]

In many older homes steel water pipes were used for electrical grounding. Today most repairs on steel pipe are performed with PVC or plastic tubing therefore, the electrical ground path should be maintained by installing a bonding strap across the plastic repair just in case wiring in the house has never been updated. Leaving this bonding jumper off could be overlooked very easily and potently be very dangerous if your pipes are used as a ground conductor.

 

[cp1969]

What about houses that have plastic water pipes?

I'm not sure grounded pipes are the safety feature that people think they are. Think about it-- if you manage to get connected with a live wire, do you want a good ground available to complete the circuit? It seems to me that a person would be better off with nothing grounded whenever electric sockets and plumbing fixtures are in close proximity. Unless you are in contact with either a ground or neutral, touching a hot wire does nothing.

 

[Inspector507]

I think I'd prefer KNOWING where that shock hazard is going.......right out to the ground like it should.

 

[Inspector507]

If your house has plastic water lines inside, then you do have less shock potential.

 

[chim]

With different appliances, etc. there are opportunities for piping to end up (unintentionally) connected to a "hot" wire. If the piping system is grounded, one of two things will happen. Either the fuse / circuit breaker will open the circuit if the current is high enough, or a small fault will be "drained" to ground.

With an ungrounded piping system, the piping will become energized. Coming in contact with a bare copper pipe (or faucet, water heater, or outside hose bib) and something grounded is fairly dangerous. Hate to have the kid try to stand on damp earth and connect the garden hose to an energized piece of metal....................chim

 

[Inspector507]

Jumper around the hot water heater

 

[Inspector507]

manufacturers jumper that was supplied with the water softener. It is too small to meet the requirements of the National Electrical Code, so it was supplemented with one the correct size.

 

[JATO_RaT]

Electric code varies throughout the country, grounding is just about the most complex of electrical code. The ultimate grounding in homes today is a ufer ground. A piece of number 4 rebar (1/2"), 20' long imbedded in concrete about 3" from the bottom of the footing where the most moisture is. A 8' copper coated rod is a second choice but not always accepted as moisture is the issue and there are instances where not enough "ground" is available to effectively ground out a system. The last and least reliable soource is a water line. Utilitity companies don't always use metal water line and often a 1" PVC or larger line is run to supply the domestic water to many homes built today. The ground is effectively non existent in water lines and although water itself may carry a small amount of grounding potential, it is still a lousy conductor compared to copper, steel or aluminum. Any break in metal piping by a non conductor should always be bonded for safety sake. I cannot think of any reason where it would present more of a hazard to do it. As was mentioned, the last thing you want is a energized faucet, freezer, gas pipe etc. Better that these have a dead short and trip a breaker then have a person touch it and pass a mere couple of milliamps through their body, it doesn't take much depending on how well a person is grounded. Bare feet, moist ground a few milliamps and you or someone else may be dead. RAT...