Periodic Ground Inspection or Testing

[GotShocked]

For LV equipment such as panelboards, switchgear and MCC’s,have you ever seen or implemented any kind of a periodic groundinspection/testing program? We are considering a program for performingat least a visual inspection annually but am struggling to come up with anypractical way to “test” a ground once it is installed and in service. Anyideas? Thanks for the help.

 

[petersonra]

my answer would depend entirely on why you want to do it, and just how you hope to benefit by such a program.

personally, i think anything beyond a visual inspection is probably not going to gain you anything.

 

[GotShocked]

Thanks for responding Bob, we would like to device a test that would ensure that the grounding electrode conductor and electrode remain securely bonded and that the resistance to earth has not deteriorated.

 

[qcroanoke]

For LV equipment such as panelboards, switchgear and MCC’s,have you ever seen or implemented any kind of a periodic groundinspection/testing program? We are considering a program for performingat least a visual inspection annually but am struggling to come up with anypractical way to “test” a ground once it is installed and in service. Anyideas? Thanks for the help.

There are several members here who do a lot of grounding installs and antenna work for the cellular sites you see everywhere.
They may know where you can go look to get started.

 

[luckylerado]

There are several meters available to test this and there are also monitoring systems that can be installed that continually monitor impedance to ground.

 

[electrofelon]

Thanks for responding Bob, we would like to device a test that would ensure that the grounding electrode conductor and electrode remain securely bonded and that the resistance to earth has not deteriorated.

Except for a few specialized situations, the resistance to ground is of very little importance. Also note that many utilities utilize a MGN system. If your utility has this and you have a grounded service, then you will be connected to the utility MGN by your main bonding jumper. The MGN will have much lower resistance than any local electrode.

 

[ActionDave]

There are several members here who do a lot of grounding installs and antenna work for the cellular sites you see everywhere.
They may know where you can go look to get started.

With the work I've done on cell sites what was important was every single, cotton picken, piece of metal, (did I mention every piece?) was bonded and earthed, but the actual ground resistance was not the biggest deal. It's hard to get a good test with as much grounding/earthing as there is on a cell site anyway.

The guys at MSHA are the ones that want resistance measurements on all ground rods or other parts of the Grounding Electrode System. For those jobs we just used a megger and made sure the egc were all good. We meggered the GECs too but that didn't really mean anything. I'm pretty sure we could have filled out the form with Roman numerals and it would have been stamped and filed with no questions.

 

[zbang]

Every couple of years a mill I worked in would go and lift each IG EGC from the bus and check for continuity back to the bus; when they got one that wasn't expected they'd run down that circuit and usually unplug some unauthorized equipment. (They called it "ground hogging" .)

Neither the electricians nor the electronics techs thought it was that much use, but it was procedure and it did keep the IG system fairly clean.