grounding main panel & service entrance, pex water pipe

i will appreciate any clarification of requirements for grounding the main panel and water pipe within 5' of entering the basement.

situation- new construction (no old metal pipes), well-water, plastic pipe entering basement. plumbing is-- a few feet of PEX, branching to copper (for water heater and boiler) and pex distribution throughout the house.

A> i thought the "main panel" has to be grounded "twice" (as in my old house)-- 1) to the copper water pipe and 2) with a ground-round outside the house....with plastic pipe entering basement, where is the second ground?

B> since entering pipe is plastic, grounding the water entrance within 5' would not apply..right? is there any overriding requirement?

thanks

 

I believe this is a misconception>>>to say two are needed. You should use all available electrodes that qualify under code. Now, a cold water pipe requires a second electrode (such as ground rods)—this may be where the confusion comes from!? Since your site is new construction. You could have used the ufer and been done with it.

Right!! Only thing you would need to do is drive two rods. Also, you will need to bond any metallic piping that may become energized. This could include gas pipe, water sprinkler pipe, etc.. Note: The piping can be bonded using the equipment grounding conductor associated with the appliance it serves. Also, you can always use the old metal cold water pipe, if it’s still in place, and is in direct contact with earth for 10 or more feet.

Sorry, I didn’t get too detailed.

 

Nitpicking.

For a plumbing system with plastic pipe exiting the house the intent is to bond the metal parts to the electrical system ground*, as opposed to bonding the electrical system to the plumbing.

Gas piping needs to be bonded to ground also, although gas pipes do not qualify as grounding electrodes.

However bonding itself is commutative i.e. if A is bonded to B then B is bonded to A.

Most locations require two ground rods. If the ground conductivity is within certain limits as shown by test equipment then just one rod is required.

* To the grounding electrode system consisting of ground rod(s) and the fat wire (grounding electrode conductor) from there to the panel and/or metal water pipe exiting the house and/or a re-inforcing rod if any within a concrete foundation if any (Ufer ground).

 

allanj.thanks..the heat is oil. there is a propane tank for a fireplace. the only visible gas pipe small length of iron pipe from the tank to basement, rest is plastic coated, flex pipe.

 

seaon..thanks

i had no control over what materials were used..it is plastic pipe and have to deal with it

so i need to bond the small section(s) of copper that branch from the main pex to feed the boiler.

 

The equipment grounding conductor run in the circuit for the boiler can bond the short copper pipes. No need to do anything else.