Cold water grounding


Hi all,
I think I have a problem. I was doing some stuff in my basement and I noticed that the ground wire from the service panel was strapped to a copper cold water pipe. The problem is that the copper pipe with the ground then is then attached to a CPVC pipe so the copper just ends. Is it the copper pipe itself that carries the grounding or is it the water inside the pipe that does it. I have this bad feeling that my service panel is not grounded. What do you think? To take it a step further, what method can I use to test the service panel to see if it is, in fact grounded?
Thank you in advance.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Open your main service panel and look for large, possibly bare wires attached to the neutral/ground buss, that are not connected to any cable and leave the panel as individual conductors. If they have insulation on them, it should be marked with green tape. Depending upon the size of your service, they could be #8,6, or 4, or larger for larger than 200 amp services. If you follow these wires, one should go to a ground rod(s) and the other clamped to the cold water pipe

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
coustanis wrote:

Likely the box has a independent ground to ground wires outside. There should also be a ground coming from the service and one going to any metal water pipes you have. Relying on water pipes to provide ground is no longer code.
--
Joseph Meehan

Dia \'s Muire duit
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Older homes that originally had fuse boxes were routinely "grounded" with the water pipe. The ground wire went to where the water pipe entered the house. That would preserve the ground in cases where plastic pipe was installed inside the home. Problem is that if the water utility decides to "upgrade" their service the odds are that they will go to PLASTIC mains (up to 10").
They are doing that in the more built up areas "around here." The "drops" (from the street line to the house) seem to be copper. I suspect that was done mainly to not have to pay the customer to put in ground rods.
But everything seems to be plastic whenever possible today. The low pressure gas lines (up to 8" by my directly observation) are plastic. The drops are plastic. They protect the plastic above ground with a metal sleeve when it enters the meter.
Grounding can be a serious concern. We have an unusual situation with a 400' run from our house to the transformer but we "lost" the neutral once. If the neutral to the transformer is intact, the ground rods or water pipe just don't make any difference. If the neutral is broken it's not obvious that a two un-tested ground rods could keep you from getting a shock.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Here in Florida, there are some restrictions as to using bare copper that comes in contact with sandy soil -- seems that the salts become conductive and can lead to accelerated corrosion. Does anyone have any experience with this?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
coustanis wrote:

Re-think time. It is not the electrical service that is grounded through the water pipes, it is the water pipes that are grounded through the electrical service.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Really? I thought it was the other way around. What would electrify the water pipes to require this? I'll try to follow the larger, bare wires from the buss and see if I can trace them to a proper ground. Hopefully they won't go hidden on me.
Thanks folks.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
If your underground water supply pipes were copper, they would indeed be grounding the electrical system, but in your situation, the system is grounded by the rods, and bonded to the internal piping to protect you in the event that an internal pipe contacted something live. If the piping wasn't bonded to the system, nothing would cause the circuit breaker to trip if this occurred
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Hopefully, nothing. But, there's always the possibility that, say, you'll drop your electric razor in the sink with the water running, etc - better to have the juice short to ground through the water pipe than through you.

Yup, if you have a big bare copper wire going back outside and then disappearing underground, you're probably OK. If not, you may want to consider driving some grounding rods.
nate
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The pipes coming into the house from the well are indeed black plastic, not metal. There is so much goofy stuff going on with this house it could easily have been changed incorrectly before I bought it. I'll look for that ground. An ohm meter would be useful here when I find it to ensure connection.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.