Gutter shock!

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satcom1

Member
Location
DFW, Tx
If this is off topic let me know.

When doing some gardening barefooted I was going to remove the gutter downspout to put in a rainbarrel. I was holding the metal shank of the screwdriver to scratch the pain off the screw head. That's when I recieve 120VAC...After the cussing binge slowed, I got my meter out...Sure enough there was 124VAC from the gutter to the copper sprinkler head located nearby.
Also, I measured 35VAC from gutter to porch light case. And it did trip a GFCI. One breaker would eliminate the 120volts. That was yesterday.

Today, 2.5 to 7.5VAC gutter to gnd BUT we found the metal foil radiant barrier was at the same voltage. the 120VAC was never seen again.
The electrician and I checked a lot of things with nothing conclusive:
- no loose bonding/gnd in panel
- several things made the voltage fluctuate some but always in the 2.5 to 7.5 VAC range.

New roof about 4 months ago.
No ground rods in subdivision. Assuming (!) cold water ground.
Oncor came to check service entrance, no issues he could see other than there was a ~2VAC difference pre and post meter.

Let me know what steps besides:
-cable locate
-install gnd rod and attach to panel

Regards:confused:
 

SG-1

Senior Member
If you do not have a grounding electrode system, rods or other type it would be prudent to have them installed. It will not have any effect on the energized gutter though.

A gutter fastner ( screw or nail ) may have pierced an ungrounded conductor. By moving the gutter slightly it's connection with the fastner was broken.

Put your shoes on. :grin:

Then, wearing leather gloves you could try measuring between each fastner on the gutter, paint removed, to a known ground, sprinkler head ?

Or use a non-contact type voltage indicator. The paint on the fastners becomes a non-issue.

Measure for current on the GEC.

At this point we are only assuming the gutter was energized. An inductive ( non-contact ) voltmeter would be helpful in determining exactly what is energized.
 

mcclary's electrical

Senior Member
Location
VA
The reference to the sprinkler should be disreguarded, since most sprinklers have NM piping. Are you certain it was not static. There is a possibility you recieved a static shock, and then read induced voltage. About not having rods,there are most likely CEE's in your neighborhood.
 

ctmike

Senior Member
I had a case of someone getting a schock off the gutter and sure enough there was voltage present traced it down by trial and error and found that the sider had used 3 inch nails to to attach the flashing and it had pierced the hot conductor have fun looking
 

satcom1

Member
Location
DFW, Tx
Pic of said offending gutter and/or 120vac

Pic of said offending gutter and/or 120vac

-It was not static. Take a look at the meter in this pic.
-The sprinkler is on a copper/brass riser that goes down about 18" in this location.


shock.jpg
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
Did you find out what on the breaker you turned off was causing the 124 volts? An easy way to determine if you have another fault originating inside or outside, is to turn off the service disconnect, if the voltage is still there, it's originating before that disconnect, if it disappears, it is past the disconnect. Divide and conqour! The voltage may not even come from the transformer feeding your house, could be from a neighbors house a block or more away! This happens a lot with lake houses, I have been told, here in Georgia, Lake Lanier has a potential of 2 volts to the POCO grounds lake wide.
 

PetrosA

Senior Member
Aside from checking your breakers one at a time to see if it's your circuit or a neighbor's, I would also run a clean ground out to the middle of the yard and check that to both the sprinkler riser and downspout. If it's the riser, you probably have a compromised UF somewhere. If it's the downspout, you'll have to start taking it apart to see where the hot section is. Since the exterior wall is brick, if it is the downspout that's hot I'll bet it's a section of drip edge that got nailed on with some long nails or they nailed a gutter hook through a wire feeding soffit mounted floods or recessed lights.
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
My Theory of the Day:

You have a roofing nail somewhere piercing a conductor that was run too close to the surface. When there is enough moisture on the roof, you get a path to the gutter, then you are completing the path to ground. Later when it dries out, there is not enough moisture on the roof to allow conduction to the gutter.

Find which breaker it is as the others have said, then you can trace the conductors to see where your roofers hit it.
 

mcclary's electrical

Senior Member
Location
VA
Stretch THHN to the service and reference the meter to that, the gutter might be grounded,and the piping may be hot, I would reference to the service, and the a ground in the yard (preferably a POCO pole support anchor.)
 

dhalleron

Senior Member
Location
Louisville, KY
I found something similar once. Except someone was pressure washing an exterior wall and got a shock. I tracked it down to one nail in the wood siding. It pierced a cable to a kitchen plug. I had to disconnect that cable and run a new piece.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I had to disconnect that cable and run a new piece.
You could have just stripped the pierced conductor and made it the EGC, and made the bare the new hot by taping it black.













I'm kidding! I'm kidding! I'm kidding! I'm kidding! I'm kidding! :D
 
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