Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 03-25-2010, 02:53 PM   #1
Newbie
 
Join Date: Mar 2010
Posts: 7
Share |
Default

Grounding issues/questions


Hi Guys,


I suspect that the water pipe to which my electrical panel is grounded may be carrying current.
How can I measure whether the water pipe is in fact carrying current?
Is it normal for a water pipe used as a ground to carry current, or does that only happen if there is an electrical problem?


Thanks in advance.

jsp056 is offline   Reply With Quote
Old 03-25-2010, 03:07 PM   #2
Master Electrician
 
Join Date: Mar 2010
Location: Indiana
Posts: 2,782
Default

Grounding issues/questions


It is not normal. What are your suspicions?

brric is online now   Reply With Quote
Old 03-25-2010, 03:13 PM   #3
nap
You talking to me?
 
nap's Avatar
 
Join Date: Dec 2007
Location: sw mi
Posts: 5,407
Default

Grounding issues/questions


yes, it can be tested but what would make you believe it is in fact carrying a current?
nap is offline   Reply With Quote
Old 03-25-2010, 03:35 PM   #4
Newbie
 
Join Date: Mar 2010
Posts: 7
Default

Grounding issues/questions


brric & nap, thank you for your replies.

The reason I suspect a current is because I have measured an unusually high level of EMF on the pipe using a gaussmeter.
jsp056 is offline   Reply With Quote
Old 03-25-2010, 03:40 PM   #5
nap
You talking to me?
 
nap's Avatar
 
Join Date: Dec 2007
Location: sw mi
Posts: 5,407
Default

Grounding issues/questions


the first thing I would do is turn off the main power to your house and re-check.

If you still have a reading, there is something other than your power causing the problem.
nap is offline   Reply With Quote
Old 03-25-2010, 03:43 PM   #6
Master Electrician
 
Join Date: Mar 2010
Location: Indiana
Posts: 2,782
Default

Grounding issues/questions


If you have access to clamp-on ammeter see if it gets a reading. Visually inspect the neutral connections for your service at the pole and at the house.
brric is online now   Reply With Quote
Old 03-25-2010, 03:54 PM   #7
Newbie
 
Join Date: Mar 2010
Posts: 7
Default

Grounding issues/questions


Quote:
Originally Posted by nap View Post
the first thing I would do is turn off the main power to your house and re-check.

If you still have a reading, there is something other than your power causing the problem.
If I turn off my electrical panel, the high reading is still there (although not as high as when the panel is on with lights & appliances in use), however with the panel still off if I then disconnect the ground from the pipe the reading drops.
At this point, I should explain that the same water pipe runs to 3 other townhomes, and all 4 units are grounded to the same pipe. However, there is only a high reading when my electrical panel is grounded to the pipe.

Last edited by jsp056; 03-25-2010 at 04:02 PM.
jsp056 is offline   Reply With Quote
Old 03-25-2010, 04:00 PM   #8
Newbie
 
Join Date: Mar 2010
Posts: 7
Default

Grounding issues/questions


Quote:
Originally Posted by brric View Post
If you have access to clamp-on ammeter see if it gets a reading. Visually inspect the neutral connections for your service at the pole and at the house.
Thanks - I'd probably need to get an electrician to look at that as it's beyond my level of knowledge.
Would you expect to see a reading with the clamp-on ammeter under normal circumstances?
jsp056 is offline   Reply With Quote
Old 03-25-2010, 04:09 PM   #9
Master Electrician
 
Join Date: Mar 2010
Location: Indiana
Posts: 2,782
Default

Grounding issues/questions


Quote:
Originally Posted by jsp056 View Post
Thanks - I'd probably need to get an electrician to look at that as it's beyond my level of knowledge.
Would you expect to see a reading with the clamp-on ammeter under normal circumstances?
No, not normally.
brric is online now   Reply With Quote
Old 03-25-2010, 06:25 PM   #10
nap
You talking to me?
 
nap's Avatar
 
Join Date: Dec 2007
Location: sw mi
Posts: 5,407
Default

Grounding issues/questions


I think it sounds like a neutral problem. Time to be cautious with electronic gear.


contact the power company and/or whoever deals with any common elements of the townhomes.
nap is offline   Reply With Quote
Old 03-25-2010, 07:26 PM   #11
Newbie
 
Join Date: Mar 2010
Posts: 7
Default

Grounding issues/questions


Quote:
Originally Posted by nap View Post
I think it sounds like a neutral problem. Time to be cautious with electronic gear.


contact the power company and/or whoever deals with any common elements of the townhomes.
So the cause for a neutral problem is likely to be external (power company responsibility) rather than caused within my own home (for which I'd need my own electrician)?
jsp056 is offline   Reply With Quote
Old 03-25-2010, 08:37 PM   #12
nap
You talking to me?
 
nap's Avatar
 
Join Date: Dec 2007
Location: sw mi
Posts: 5,407
Default

Grounding issues/questions


based on the fact you still have, at least part of the problem current, even with your power turned off, I would suspect it is a problem common to all of those townhouses involved. That would either be the power company or whomever deals with the common elements of the townhouse group.

I would suspect it is part of the power company's system and is a poor neutral connection where it feeds to the houses. Since they ground their systems, and neutrals, it sounds like the water pipe is being utilized as a replacement or at least a parallel conductor for that neutral and it's poor connection.
nap is offline   Reply With Quote
Old 03-25-2010, 08:49 PM   #13
Newbie
 
Join Date: Mar 2010
Posts: 7
Default

Grounding issues/questions


OK, thank you for your help nap, I'll look into that.
jsp056 is offline   Reply With Quote
Old 03-25-2010, 09:50 PM   #14
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,856
Default

Grounding issues/questions


If you disconnected the ground clamp from the water pipe and then tried to measure voltage between the ground wire and the pipe, you might detect a problem possibly with your neutrals.

If you disconnected the ground clamp from the water pipe, also measure voltage between neutral and both hot lines to see if there is a difference.

Should you find a significant voltage difference between the two legs of the 120/240 volt service (to neutral) and all circuits are affected, and reconnecting the ground clamp to the water pipe makes the difference less profound, then there is a good chance there is a neutral problem on the power company's lines.
__________________
Stop wasting time re-adjusting the pattern. Have several lawn sprinklers, one for each pattern.
AllanJ is offline   Reply With Quote
Old 03-25-2010, 11:10 PM   #15
Newbie
 
Join Date: Mar 2010
Posts: 7
Default

Grounding issues/questions


Thanks AllanJ - I'll discuss that with my electrician.

jsp056 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
grounding electrode conductor question bsperr Electrical 8 12-05-2009 09:23 AM
grounding of main panel and sub panel in older house linkysys Electrical 2 10-01-2009 04:34 PM
Grounding Method Steelhead Electrical 6 02-05-2009 11:06 AM
Grounding light box n0c7 Electrical 10 10-06-2008 03:20 PM
NEC Question Jafsvcs Electrical 1 06-13-2007 05:45 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.