Hi all,
My 90+ y.o. house is not grounded very well. First of all, I have just learned I have illegal plumbing connections going on. I have copper and galvanized coupled together. So we will be removing most of that and going with pex for the plumbing...
My electrical box is grounded to a section of galvanized water pipe and it is a good 15 feet or more from the water main in the house. I have been told if you are grounded via a water pipe it should only be 5 feet from the water main...
So, since most of the water pipes are coming out, I need a new grounding system... An electrician working next-door at my neighbors house just told me two ground rods 8 feet deep well apart from each other and we'll be good to go...
I do have my nice audio system, so i am wanting to sure this grounding is done well. I do not know if I am interested in getting the dedicated system outlet separately grounded, as we will be selling this house next year and the added expense of that might not be worth it at this time...
Thanks and I hope someone is here soon to help wit some dos and don'ts I should ask for or watch for...
Jason
First I would suggest you hire an electrician to update the main grounding system of the electrical service of your house. Local Code may require more than just bare minimum NEC code requirements.
I have just learned I have illegal plumbing connections going on. I have copper and galvanized coupled together.
Did the plumber tell you he can install a coupling/union that insulates/isolates the metals from one another? A grounding bonding jumper is then installed around the coupling/union.
My electrical box is grounded to a section of galvanized water pipe and it is a good 15 feet or more from the water main in the house. I have been told if you are grounded via a water pipe it should only be 5 feet from the water main...
Yes, per NEC (National Electrical Code) the connection to the incoming water pipe must be made within the first 5ft where the pipe enters the house. (The water pipe must be in direct contact with the earth a minimum of 10ft) The water meter must have a bonding jumper installed around it. Per current NEC the above is still required.
2014 NEC 250.50 Grounding Electrode System. http://lightning.org/wp-content/uploads/2014/12/Bonding-2013-ULPA-LPI-rev1.pdfSo, since most of the water pipes are coming out, I need a new grounding system... An electrician working next-door at my neighbors house just told me two ground rods 8 feet deep well apart from each other and we'll be good to go...
The minimum number of earth driven ground rods can be determined by local city electrical codes. Bare Minimum length of the rod per NEC Code is 8ft. Bare Minimum distance the rods are apart from one another per NEC is 6ft. Bare Minimum.... Going from memory IEEE recommends the minimum distance be the length of the ground rod used. For 8ft rods the distance would 8ft.
I personally would use 5/8" x 10ft ground rods driven a minimum of 10ft apart. For my electrical service I drove 3 steel copper clad 5/8" x 10ft ground rods 12ft apart from one another. Though NEC Code says the bare minimum copper wire size that can be used to connect the rods together then to the electrical service neutral bar in the electrical panel is #6awg copper, I used #4awg bare solid copper wire. Remember, NEC is bare minimum.
As for the size of ground wire (Grounding Electrode Conductor) that will be installed from the neutral bar on the main service electrical panel to the incoming domestic water pipe the size is determined by NEC Table 250.66.
Per NEC if the domestic incoming water pipe is metallic the electrical service grounding system must connect to the water pipe within the first 5ft where it enters the house. Where a metallic water pipe exists at least one 5/8" x 8ft ground rod must be driven outside the house. Local code may require two or more.
Local code, AHJ, (Authority Having Jurisdiction) has the final say as to what is required. The electrician, from your area, will know the bare minimum requirements.
You can exceed the bare requirements if you like for added lightning protection.
It all comes down to time and money.
The main grounding system for the electrical service of your home should be updated and installed by a qualified State Licensed Electrician. Ask to see his current up to date license. While working he should have it with him at all times.