Pex and grounding

[bubblegummom]

Hi!

I've been reading some plumbing books, trying to learn something.

One sentence I don't understand says, "If your metal supply tubes are used to ground your electrical system, you'll need to provide a jumper if Pex is installed midrun."

What does that mean?

[HayZee518]

basically what this means is if any of your water lines are of PEX or plastic, then your water system is NOT GROUNDED! the same is true if your house is piped with genova plastic pipe then the fixtures are not grounded and if unintentionally energized by an electrical current, using these fixtures can potentionally kill you if conditions are right. so if you have a piece of PEX in the middle of a run of copper tubing the you'll need to apply a grounding clamp on each piece of the copper tubing and jumpering each clamp with a piece of #8 bare stranded copper wire to continue the bonding.

[mrcaptainbob]

Grounding....

Hmmm, this raises a concern. My nwhole house is copper, except for the connection to the plastic line from the well. THe house electric is grounded to two copper ground rods from the main panel. Should the copper system be 'bonded' to that ground wire from the main? What about the copper heat sytem running the baseboard rads? Those too?

[HayZee518]

the well casing I'm assuming is bonded, grounded through the equipment grounding wire. in addition to the earth ground, several driven ground rods further ground your electrical system. the rods, well casing should all be connected together. somewhere on your system the copper heat lines, cold water and hot water lines have a grounding clamp on it (them)

[DKAudio]

From a driven ground rod you should have a bare grounding conductor to your Neutral/Ground bus in the electrical panel (many counties require bonding bushings on the mains conduit too). Then from the Neutral/Ground bus you should have another bare grounding conductor that runs to both sides of your water meter with clamps. Like HayZee said, if you have a middle run of non-metalic pipe then you must bond the other side with clamps and a bare conductor.

[numberQ]

hey, here it is sourceradix.com/m/f27.html

[mrcaptainbob]

Grounding wawter system...

Thanks for the help. I will verify the well casing (am sure it is NOT grounded), hot and cold water system and heating system are grounded.

Hey...would the hot/col water systems be grounded through the ground terminal on the water heater?

[Redwood]

That would be 1 ground connection...

[mrcaptainbob]

Grounding...

Well, then I guess I'm all set. The water heater is grounded to the main breaker panel. The copper domestic water system is grounded through connections to the water heater. The copper/iron heating system is connected to the domestic water system. Apparently all is well, then! Thanks for the help...and allowing me to hijack this thread!

[HayZee518]

not so fast! is the domestic water supply connected to the hot water tank through dielectric nipples or unions?

[LazyPup]

Dielectric nipples would have no effect on the electrical bonding of the system because dielectric nipples are simply a 4" galvanized steel nipple with a plastic internal liner. There still remains a direct physical path for electricity through the body of the dielectric nipple.

One of the leading causes of concern is when the water supply lines from the municipal main to the structure is replaced. In most cases the original water supply line was galvanized iron pip or copper pipe, and in most instances the house electrical system was grounded to the water line at the point where the line enters the structure.

Due to the extreme corrosion factors in galvanized iron pipe and the high cost of both labor and materials to install galvanized iron or copper water lines it is now a common practice to replace the lines with PE pipe (polyethelene pipe), PVC pipe or PEX pipe. When this is done there is no longer any metal pipe iin direct contact with the earth and the house main electrical system grounding is negated.

Some local codes require that when replacing the water supply line with plastic pipe there must be a minimum of 10' of copper pipe immediately before the line enters the structure.

All homeowners shourd be cautioned that if you are replacing a metal water supply line with plastic pipe you should also install a driven ground rod connected to the house electrical system to insure proper bonding.

Although the practice is now code prohibited, back in the days of all metal piping it was common practice that whenever an electrical device required a ground they simply ran a ground wire to the nearest water line. Even though grounding to water lines is now code prohibited, non-the-less we still find equipment grounds attached to water lines in older homes and if replacing a section of copper or galvanized line with plastic line in an older home it is a good practice to install a bare copper bonding wire over the plastic section as was described in the original post.

From personal experience I would also suggest that all plumbers, handymen or DIY'ers should invest in an inexpensive single probe voltage testor and they should test for the presence of electrical current on any metal pipes before they attempt to service the line.

[Redwood]

From personal experience I would also suggest that all plumbers, handymen or DIY'ers should invest in an inexpensive single probe voltage testor and they should test for the presence of electrical current on any metal pipes before they attempt to service the line.

That is very good advice!
It could save your life!

[LazyPup]

"I stayed at a Holiday Inn Express last night.
Now I can Plumb"

I worked for three months installing the plumbing in a Holiday Inn, and I still can't afford a room....LOL