Thread: Checking for ground (GES) Can't visually see ?

I was checking the electrical panel today and trying to verify what type of GES the panel had. Looked outside for a ground rod, No ground rod. Looked at the main water shut off and main had been replaced with PVC, but house still had existing galvanized water pipes. The ceiling in basement was finished so I couldn't see the copper wire connected to the pipe. Is there anyway to test for a ground (GES) without being able to visually see it, maybe with a meter ??

Originally Posted by Sam Morris

I was checking the electrical panel today and trying to verify what type of GES the panel had. Looked outside for a ground rod, No ground rod. Looked at the main water shut off and main had been replaced with PVC, but house still had existing galvanized water pipes. The ceiling in basement was finished so I couldn't see the copper wire connected to the pipe. Is there anyway to test for a ground (GES) without being able to visually see it, maybe with a meter ??

The interior water piping system is still required to be bonded even if it is not used as a grounding electrode. That leaves you with the choice of ground rods or a ufer ground. I only see one termination that could be to a grounding electrode.

Yes, you could try a ground rod impedance clamp on meter and it may tell you if you have an electrode system. Sometimes simply removing the GEC and using an ohm meter between it and the equipment grounds will tell something, barring any neutral to EG faults in the system. Also with it disconnected you could use a telephone toner and trace the conductor out. I would advise this being done with the power off in all cases..and only disconnect the GEC after using a clamp on amp meter around it to determine if there are any hidden faults that are circulating. This is not for the light hearted or the untrained..

Originally Posted by Roland Miller

The interior water piping system is still required to be bonded even if it is not used as a grounding electrode. That leaves you with the choice of ground rods or a ufer ground. I only see one termination that could be to a grounding electrode.

if the interior metalic water piping systems are discontinuous and not likely to be energized it/they may not have been required to be bonded. Nothing from the OP indicates the need nor the lack of metalic system lack of bonding relative to same.

There are other possible made electrodes and present electrodes which have not been mentioned.

It was not indicated the source of water was a municpal system, nor if there was an "other than a surface source" of water supply (i.e. well ). Additionally, "plate" electrode(s) and a ring of copper wire are other types of made electrodes and existing electrodes besides pipes, rods, and ufers, much easier employed in some conditions/areas, like sometimes found in the OP's region (ledge, high watershed ground water, etc.).

Furthermore, I don't recall the OP indicating that "the panel" being inquired about was "the service equipment" nor the meter can as service point, the supply of "the panel" nor that it was the only electrified structure, nor the vintage of the installation.

Finally, it is possible (although not (generally) considered a prefered method) that the supply was bonded before or within the meter can. I note the metalic raceway exterior and the CATV and/or Telco box bonding to the raceway. Is that lower box or access door metalic? did you open/explore it (it appears accessible)? I also note the metalic service raceway entering lower left side wall of the panel (unfortuntely when I try to "blow up" both low resolution small pictures they become pixelated? and unviewable). Agri/livestock, rural, drops via customer owned poles, etc. is not unheard of to have bonded before the panel. Metalic raceway may be employed as a conductor.

The ASHI and Washington State SOP's require that we verify there is a service ground where possible. I will usually look for the ground conductor coming in with the main service and then look for a (earth) ground coming in from the bottom of the box. Usually its going to be a large solid copper conductor coming in by itself. If its not there then I will call it out. Finding an external ground rod in new construction is pretty difficult around here. Seem's like its not being called for.


//Rick

Originally Posted by H.G. Watson, Sr.

Metalic raceway may be employed as a conductor.

How much per hour do you pay the metallic raceway?

Originally Posted by Darren Miller

How much per hour do you pay the metallic raceway?

Employ--make use of, "the methods they have employed to collect the data"

synonyms:

use, utilize, make use of

I run into this all the time and used to spend too much time trying to figure out where the ground was with no luck. I include this in my report if I can't find the ground:

"The ground wire or grounding electrode conductor for the service equipment could not be located. Grounding may be inadequate and may be a safety hazard for shock. A qualified electrician should evaluate and repair if necessary."

Originally Posted by Tom Rees

I run into this all the time and used to spend too much time trying to figure out where the ground was with no luck. I include this in my report if I can't find the ground:

"The ground wire or grounding electrode conductor for the service equipment could not be located. Grounding may be inadequate and may be a safety hazard for shock. A qualified electrician should evaluate and repair if necessary."

Tom has it right. Report what you can see, and recommend further evaluation if questions still exist that require more specialized equipment or expertise.

If I cannot see both of the main grounding connections inside the main service panel, then I insert this note into my report; "One or more of the main ground connections appeared to be missing. The ground is the emergency path for electricity, and it is a critical component of the system. Further review and correction by a qualified electrician is recommended."

If I can see the grounding cable connections in the main service panel, but cannot see the other ends, usually due to the installation of finishing materials, then this is my note; "The grounding cable destination and grounding attachment could not be confirmed or evaluated as part of the inspection due to its being hidden by finishing materials, or some other obstruction. An inadequate system ground is a hazardous condition, and should be corrected if the condition exists. Recommend confirmation of proper electrical system grounding by a licensed electrician."

NEC 2011
250.68 Grounding Electrode Conductor and Bonding Jumper Connection to Grounding Electrodes.

The connection of a grounding electrode conductor at the service, at each building or
structure where supplied by a feeder(s) or branch circuit(s), or at a separately derived system and associated bonding jumper(s) shall be made as specified 250.68(A) through (C)

(A) Accessibility. All mechanical elements used to terminate a grounding electrode conductor or bonding jumper to a grounding electrode shall be accessible.

If it's behind wall covering and its location is not identified, then I consider it not accessible.

Originally Posted by Tom Rees

I run into this all the time and used to spend too much time trying to figure out where the ground was with no luck. I include this in my report if I can't find the ground:

"The ground wire or grounding electrode conductor for the service equipment could not be located. Grounding may be inadequate and may be a safety hazard for shock. A qualified electrician should evaluate and repair if necessary."

I would re-word that to be something like this:
- The grounding of the electrical system could not be found, have electrical contractor verify and document that the electrical system is properly grounded.

There is nothing for the electrical contractor to "evaluate", but there is something for them to "verify" and "document".

Hi, guys, all is well here, just been real busy.

Long time no see, stranger.

Originally Posted by Rick Cantrell

Long time no see, stranger.

Yes, I took on too many things at one time, still have too many going on, but I'm trying to work my way through them and get a little time to check in here now and then.