Puzzling electric fence problem

[n8wrl]

I have several segments of fence charged with 6v solar chargers. I have a very puzzling problem with one segment.

We have a combination of PVC-encased fencing and electric on wooden posts. On this one segment I am getting a tickle from the metal tensioners at the ends of the PVC fencing. I have gone over the electric wire carefully examining each insulator and I can't see where the connection is.

For grins I got out my trusty ohmmeter. On the top PVC line I measure about 10Meg-ohms between the electric fence wire and the wire encased in the PVC. I measuere infinite resistence (open, or no connection) on the other lines and on the other fence segments, as I would expect. Apparently 10Meg is enough to get a tickle when the grass is wet but not with dry grass and shoes.

I have trimmed out the bulk of the fencing to just one line and I still get the tickle. It seems to travel down the wooden post to the other PVC lines as well. I have swapped out the charger. When the electric is disconnected, no shocks at all.

Some of the insulators are pretty old - is it possible current is bridging the gap to the nail?

What am I missing?

[Chuck52]

I'd check the old insulators, looking for a crack that lets current bleed through especially when wet.

Chuck

[chh]

I would agree, check the old insulators for cracks, or even heavy rust streaks from the nails. I doesn't really take much, especially with a little moisture.

[jimmyj]

I had a short because of bird poo on an insulator once. I know it's a long shot but figured it's worth mentioning.

[piller]

For grins I got out my trusty ohmmeter. On the top PVC line I measure about 10Meg-ohms between the electric fence wire and the wire encased in the PVC. I measuere infinite resistence (open, or no connection) on the other lines and on the other fence segments, as I would expect. Apparently 10Meg is enough to get a tickle when the grass is wet but not with dry grass and shoes.

I have trimmed out the bulk of the fencing to just one line and I still get the tickle. It seems to travel down the wooden post to the other PVC lines as well. I have swapped out the charger. When the electric is disconnected, no shocks at all.

You measured resistance between the electric fence wire (with charger off/disconnected) and each of the PVC lines on this section of fence? The PVC lines have a metal conductor inside and are coated with PVC? How are the PVC conductors terminated at each end, are they grounded or floating?

You said the tickle seems to travel down the wooden post to the other PVC lines as well, I'm not sure what you mean here, do you feel/measure voltage on the other PVC lines?

I have a solar fence charger, it's output is pulsed about once per second, is your system like that?

[n8wrl]

You measured resistance between the electric fence wire (with charger off/disconnected) and each of the PVC lines on this section of fence? ?

Yes

The PVC lines have a metal conductor inside and are coated with PVC? How are the PVC conductors terminated at each end, are they grounded or floating?

They are gounded in that they wrap around the metal tensioner that is nailed to the post.

You said the tickle seems to travel down the wooden post to the other PVC lines as well, I'm not sure what you mean here, do you feel/measure voltage on the other PVC lines?

I'm 'testing' by touching the tensioners - there are several on each post. I'm measuring the resistence between the top-line/tensioner and the electric fence wire with the charger disconnected. The top tensioner reads several m-ohms, all the rest read an open circuit.

But I suspect the charge travels down the wooden post because I feel a tickel on ALL the tensioners on the post.

I have a solar fence charger, it's output is pulsed about once per second, is your system like that?

That is correct. While the charger is pulsing, I feel the tickle at the same frequency. When the charger is off, no tickle.

[Soundguy]

Most solar units are pulse, high impedance type vs constant current types.

any restive connection will let high votlage travel across it.. ie wet surfaces.

I've seen bad grounds at the charger make some funny 'issues' as well.

soundguy

I have several segments of fence charged with 6v solar chargers. I have a very puzzling problem with one segment.

We have a combination of PVC-encased fencing and electric on wooden posts. On this one segment I am getting a tickle from the metal tensioners at the ends of the PVC fencing. I have gone over the electric wire carefully examining each insulator and I can't see where the connection is.

For grins I got out my trusty ohmmeter. On the top PVC line I measure about 10Meg-ohms between the electric fence wire and the wire encased in the PVC. I measuere infinite resistence (open, or no connection) on the other lines and on the other fence segments, as I would expect. Apparently 10Meg is enough to get a tickle when the grass is wet but not with dry grass and shoes.

I have trimmed out the bulk of the fencing to just one line and I still get the tickle. It seems to travel down the wooden post to the other PVC lines as well. I have swapped out the charger. When the electric is disconnected, no shocks at all.

Some of the insulators are pretty old - is it possible current is bridging the gap to the nail?

What am I missing?

[mbohuntr]

I believe the problem may be a cracked insulator. if your using an ohmeter, you cannot measure the ablity to arc. The problem should diminish with drier weather like a cracked distributor. Try lifting the wire while someone measures the voltage. A sharp rise in volts means you found it.

[heehaw]

check it at night, you can sometimes see a little arch at night that is really hard to find otherwise.
heehaw

[tallyho8]

Simply slowly drive your fenceline with your radio tuned to an AM station. When you get a lot of static in your radio pulsating about every second, you are near the bad spot in the fence.