No grounding cable( old house cable)

[sallev]

Older homes were wired without branch circuit grounds in available cable. A rewire is an expensive undertaking and I was wondering if there is some less expensive solution.GFCI outlets replacing the old two prong outlets is the only solution that comes to mind.

The code will only permit a single ground clamped at the incoming copper water line.Incorporation of more than one ground wire locations clamped to the copper water line seems to be a possible solution. Would the ground currents be that prohibitive ?

I can't find any provision in the code that addresses this issue.

 

[petersonra]

Older homes were wired without branch circuit grounds in available cable. A rewire is an expensive undertaking and I was wondering if there is some less expensive solution.GFCI outlets replacing the old two prong outlets is the only solution that comes to mind.

The code will only permit a single ground clamped at the incoming copper water line.Incorporation of more than one ground wire locations clamped to the copper water line seems to be a possible solution. Would the ground currents be that prohibitive ?

I can't find any provision in the code that addresses this issue.

There is supposed to be no current flow at all in the ground wire.

Where does it say you can only connect one wire to a water pipe?

 

[charlie b]

I might be misunderstanding your question. But it seems to me that you are confusing two things:

(1) The Grounding Electrode Conductor, or GEC (i.e., the wire from the service to the water pipe or to a ground rod or some such thing), and

(2) The Equipment Grounding Conductor, or EGC (i.e., the wire that provides the "safety ground," and that is connected to the third prong of receptacle outlets).

You cannot solve your problem by connecting wires from receptacle ground points to water pipes at various places throughout your house. NEC Article 300.3(B) specifically requires that all wires in the same circuit, including phase conductors, neutral wires, and EGCs, must be in the same cable or in the same conduit.

Please note that if you are planning on doing some electrical upgrade work on your own, we will be permitted to assist you. This Forum is intended to assist professional electricians, inspectors, engineers, and other members of the electrical industry in the performance of their job-related tasks. However, if you are not an electrician or an electrical contractor, then we are not permitted to help you perform your own electrical installation work.

 

[busman]

Charlie,

Please check 250.130(c) and 250.134(b)ex.1

Mark

 

[eprice]

However, since 250.52(A)(1) prohibits the use of interior metal water piping located more than 5 ft. from the point of entrance to the building as part of the grounding electrode system, most of the copper water line in the building would not qualify under 250.130(C)(1) and would not be an acceptable location for the connection of an equipment grounding conductor.

 

[Bob NH]

Other Water Pipes for Ground

Other Water Pipes for Ground

Connection to a water pipe for a ground is usually taken to mean the water supply pipe entering the building.

There are a lot of places where internal water pipes are located under the slab. Sometimes they are distribution pipes for hot and cold water. Sometimes they are pipes to circulate water in hydronic heating systems. In most cases they enter and leave the concrete floor into the open space at both ends and don't exit the perimeter of the building.

Does the code permit using such pipes to meet grounding requirements as long as the connection is made within 5 feet of the point where the pipe leaves the concrete floor?

 

[haskindm]

Salev,
Check 250.130(C) for the instructions for replacing non-grounding receptacles. You will find that using a GFCI is ONE of the acceptable methods.

 

[hillbilly]

250.130(C)
If I'm grounding receptacles in a old house, I usually run a #8cu solid from the panel supplying the circuit (or from the GEC) and route it any way that I need (250.120 (C) to get it near the target receptacle(s). From that point I will use a split bolt to tap off of this #8 to a #12cu (250.122) that runs to the receptacle.
steve