[RFI] Electric Fence pulsing (will get worse soon !)

[Don Shelton]

Worked on many, many electric fences in CO growing up farming and ranching throughout Pueblo County. Big to small farms and all kinds of animals. One thing farmers do is always try it first with whatcha got; if that don't work, then spend what ya must to protect the animals. 
We would always wire up the whole expanse of the fields and then troubleshoot as needed. Almost any charger and fence working properly should put you on your behind if you just touch it. In fact, you should be able to hear it around the whole perimeter unless there's just no humidity; or you have a short. With a good ground at the device, and a smaller fence charger, you can also grab the fence real hard with a fist causing a soft short and folding back the relatively high impedance multiplier so it just hurts a "little."
Now, when things don't work right you start cutting back on "things." Take off any dual or extra runs until you get the buzz in the air. Next start cutting the long runs in half to see when it starts working; clear back to the charger of you have to. Hopefully you've already run a short wire out a few feet to make sure the charger is really working. Once you find the longest piece of working fence then you start cutting the non working pieces in half and adding them back in until you've isolated a small enough piece to troubleshoot. 
Realize that many "small" shorts or even weeds, and sometimes fence posts, are cumulative and slowly reduce the charger's effectiveness. That's just plain hard to find sometimes. And if the fence really is too long for the charger then just capacitive coupling to the air and ground will render a too-small charger ineffective. 
Best of luck. Just break'er down int small pieces till you get it working. 
Don, N0KGU



On Jul 22, 2015, at 11:59 AM, donovanf at starpower.net wrote:

Hi Mike, 


A time domain reflectometer makes quick work of identifying the locations of 
faults in an electric fence. Maybe you can find a ham who will loan one to you. 
Properly installed its resistance to ground should be many thousands of ohms. 


73 
Frank 
W3LPL 

----- Original Message -----

From: ve9aa at nbnet.nb.ca 
To: kgordon2006 at frontier.com 
Cc: RfI at contesting.com 
Sent: Wednesday, July 22, 2015 5:41:40 PM 
Subject: Re: [RFI] Electric Fence pulsing (will get worse soon !) 

Hi Ken, 

I am taking this step by step and yes, the owner is working with me, but I have to first convince him I know what I am talking about. WE've never encountered each other before, so we have no history. I want it to be a good one. I told him about my concern about him losing his horses. I said I help you, you help me. He seemed to like that. 

I am a ham, ex apprentice electrician and current EE TEchnologist so at least have some idea what I am talking about ;-) 

Electric fences are new to me, but Electricity is Electricity. 

It's slow going, but he's not resistant. Just very busy like most folks. Has a day job outside horses. 

Two weeks ago he redid a connection or two (more to go)-no real change. 

Last week he added another short ground rod and one large ground plate this last weekend. . (we cannot really drive a rod here more than 1-2 feet, max. 

This morning @ 7am I noticed it was off.....whatever that means. Could be he was redoing a connection before he hustled off to work. 
.... 
Since yesterday I now know his make and model so I have printed out a manual for him highlighting 7 or 8 times in there that says (essentially) "weeds are bad and it won't work touching the weeds" so I will drop that off tonight and/or tomorrow. 

I bought a fence tester and told him he could use it any time he wanted and/or I would help troubleshoot it. Not forcing me to do it for him. Getting him to ask ME to help him more or less. 

BTW, I was NOT able to even measure 300v is what I said. I touched it last night (with him as a witness) as the fence came around the last part of around 1000' of wire-rope and barely felt a spark.....so maybe a couple hundred volts? (a wild guess) 

I'll get there. WIth your guys help and my work with him. 

The very worst thing I could do is go waving around my rights and rules and my ham license. Not sure who told me that, but that's not how we do things here in NB. I appreciate the advice, but I am months if not years from doing that. Strictly a last resort ! 

Mike VE9AA 
---- "Kenneth G. Gordon" <kgordon2006 at frontier.com> wrote: 
>> On 21 Jul 2015 at 19:07, Mike Smith VE9AA wrote: 
>> 
>> Large red box built by PARMAX. SOLAR PAK 6 Model DF-SP-L1 (Kansas City)
> 
> OK. I just checked the manufacturer's site. The specified voltages are: 
> 
> 11.5 KV when the entire fence is "open circuit" and 2650 Volts at 500 ohms. 
> 
> From your report, you measured something like 300 volts at one point, and 
> even less at another. 
> 
> 300 Volts, if that is an accurate measurement, indicates an impedance of 
> less than 60 ohms. (2650/500=300/X) 
> 
> There is DEFINITELY some sort of short-circuit somewhere in that fence 
> system. 
> 
> I REALLY think that even you could "feel" a 2600 volt pulse!!!! I know I sure 
> could!!!! 
> 
> Also, the unit is specified for use in small to medium pastures, whatever that 
> means. 
> 
> There is most certainly something wrong with the installation. My suggestion 
> to disconnect, completely, the bottom strand of the system, then to re-check 
> its performance with only the top, completely clear (supposedly) strand would 
> at least make the issue more clear. 
> 
> Someone else here with far more experience than I with farms and electric 
> fences also said that in his opinion there was definitely a problem with the 
> installation. 
> 
> Have you yet compiled the info we have tried to share with you and 
> presented it to the other fellow? 
> 
> Have you taken this man to the point in his fence system where YOU felt 
> almost nothing and had him "test" it himself? 
> 
> If you cannot convince him of 1) your competence in such matters, and 2) 
> that there IS a problem with his installation, and 3) that it is MOST LIKELY 
> his installation that is causing severe interference to your federally licensed 
> radio station, then maybe you had better consider calling in some "bigger 
> guns" if such exist in your area. 
> 
> To my way of thinking, this has gone far enough. 
> 
> Ken W7EKB

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