How do I check for electrified water in the crawlspace?

ericsarratt

Senior Member
I work in crawlspaces quite a bit. Sometimes they have some water.

If there is a lot of water I pump it out before working, but even then the soil is still saturated.

Is there a way to use a meter, or some type of device, to check for electric current running through water or the wet ground?

LarryFine

Master Electrician Electric Contractor Richmond VA
I'd try a dual-range non-contact tester, first set to high voltage, then to low.

hillbilly1

Senior Member
A widow maker might be the easiest.

suemarkp

Senior Member
There is always current running through the ground. It is the voltage gradient that is the problem, not current. Normally, the voltage gradient is very low. If there is something electrical faulting and it is sitting in the wet, or on a metal strut into the earth, that puts 120V into the earth at that point. Typically, the voltage would be down to near zero about 4 feet away from that faulted object (assuming a 120V to ground electrical system). So crawling around in the dirt 4 feet or more away from that fault isn't a problem. Getting next to that faulted item, with your hand close and you knees further away can put current through your body. It doesn't take a lot of voltage to feel it when you have body parts (hands, butt, or knees) pushing on wet dirt.

A "non contact tester" could maybe find a 50 volt gradient if you ran it in the dirt in front of you, but you'd need to get it close (within a foot or two) of a faulted item in order for it to detect it. You could also touch a pipe or other metal item with that tester before you touch it with your hands, which is probably a more effective use of your time. FInding a voltage difference of less than 50V is harder. You'd probably need a meter for that and a short stake to put one side into the dirt. You could probably feel a tingle down to about a 10V level if you are in wet dirt, although that probably won't hurt you.

What kinds of shocks have happened to you in the past? That could perhaps help with what procedure or equipment to use to help you avoid that in the future.

Senior Member
I'd be more concerned with what's around you as you go in.
I would certanily test the drain and what pipelines and other metalic's things around them.
You can stick a meter lead in the dirt, but SueMark nailed it

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Staff member

Removed it.

ericsarratt

Senior Member
Wow! Thanks! I have a non-contact tester; I had not thought about using it.

I'll start tapping the wires and pipes in the vicinit

mtnelect

HVAC & Electrical Contractor
Wow! Thanks! I have a non-contact tester; I had not thought about using it.

I'll start tapping the wires and pipes in the vicinit

When crawling I always use several sections of cardboard laid flat, and always turn off the electricity ! And what I have run into, is another story. Glad that I am not doing that anymore !!!

mtnelect

HVAC & Electrical Contractor
When crawling I always use several sections of cardboard laid flat, and always turn off the electricity ! And what I have run into, is another story. Glad that I am not doing that anymore !!!

For me, crawling has always been kind of scary, I guess I am a "whimp".

petersonra

Senior Member
Send in the apprentice first.

hillbilly1

Senior Member
Send in the apprentice first.
I was working on one of my boss’s cabins in South Georgia, when I opened the crawl space door, a big ol’ snake skin was laying there. Sent my helper in! LOL! On his other cabin, I didn’t have my helper, but it had a taller crawl space. There was a small rat snake curled up where the A/C lines came in. I left him alone, he left me alone! LOL!

Joethemechanic

Senior Member
You could always ground the dirt

Joethemechanic

Senior Member
No, that's earth the dirt.
If you drove ground rods all around the perimeter of the area and connected them all with a loop of wire you would create an "Earthing Eruv" and the area inside would be safe

brother

Senior Member
I've heard of people attaching these shock alerts or something similar to a stick and pushing it in under the crawl spaces to test for voltage. Alot of these pool/fountain electrocutions happened in less than 50 volts because of the voltage gradient. So the non contact tic volt tester is better than nothing but it may not get the main job done.

petersonra

Senior Member
If you drove ground rods all around the perimeter of the area and connected them all with a loop of wire you would create an "Earthing Eruv" and the area inside would be safe
Suppose the rods you pounded in all had a 25 ohm impedance to earth? How would they protect you from anything.

Joethemechanic

Senior Member
Suppose the rods you pounded in all had a 25 ohm impedance to earth? How would they protect you from anything.
It was a joke

The eruv is a boundary that allows observant Jews to carry needed things in public on Shabbat.

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drcampbell

Senior Member
I never did understand why that was necessary, nor what it does (if anything) or how it works. (if "works" is even the right concept)

As for the original question, I suppose you could fabricate a pipe loop, maybe 2 feet by 5, lay it down on the dirt and do all your crawling inside it, moving it a step at a time as you move yourself. It'll make a mediocre electrical connection to the dirt, but it only needs to make a better connection than you do.

Many firefighter's boots are electrically protective. I don't know whether that protection is available in hip boots that would also protect your knees. If they are, they would protect you from a hands-to-knees electrical gradient.

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don_resqcapt19

Moderator
Staff member
If you drove ground rods all around the perimeter of the area and connected them all with a loop of wire you would create an "Earthing Eruv" and the area inside would be safe
Not really...the effect of the grounding electrode in raising the voltage of the earth to make is safe is only effective within a few feet from the grounding electrode.