Electric fencing, circuits and leakages.

Buford T. Justice XIX

L1985 wrote: »

I think you need to be an electrical engineer with all of this! It’s a great help so thanks . The first one I was sure it would be fine but I was also sure with my first question so...!
I only chanced the two fencers a few weeks back so I won’t be doing that again I’ll divide the lines and might get a solar fencer for up there anyway.

I don’t know the joules-they are the elephant ones? Just been having problems with them and it’s bullocks who are on the bold side and can smell when the fence weakens! It’s caused issues the past three years since I’ve been putting them up there so I might seriously look into the solar. It’s only a mile of fence bit the fencers don’t seem to be lasting.

The first thing would be to sort out your earths on the fencers. Put in enough of them and connect them properly to each other and keep the soil around them moist. Use the insulated coils of wire and metal clamps to connect each earth to each other and make sure they're good and tight so there's no chance of them coming loose.

Then test the wire before connecting it to the wire and see what the output is.

Then clean off any vegetation on the wire and move it up away from grass. That'll have to be done regularly and keep an eye on the current in case it drops. You'll need a reading of at least 3 on the tester to keep animals inside.

L1985

Ok so continuing on my electricity based education which I’m realizing is sorely lacking ....Earthers-I get that they are a metal spike into the ground but why do you need more then one? And why if it’s an earther it increases the efficiency but if it’s hitting off a pole accidentally it lowers it?
Also if I’m putting in more then on earther why should they all be in the same spot? And I’m getting from the above all have to be connected ? And why is more then one better? We have only one at home so looking at driving a second one based on this anwser!!
Btw you can see I was a fun child-I hate being told “because” and that’s my dads favorite anwser!!

Say my name

The more surface area of an earth you have the greater the negative pole on the fencer unit and the greater the positive charge going out along the fence line.
If there's more of an earth on the fence line than your earth bars the polarity of fencing unit gets reversed and the shock goes into the earth bars and you'll have nothing on the fence line.

So the more bars the better as you'll have a greater surface area and contact with the earth itself but spread them out about 1 meter or more apart joined together with insulated steel cable.

The ultimate earth system would be galvanized reinforcing steel mesh buried in the ground with a bar coming up to connect to the fencing unit. Other people use diatomaceous earth around their earth points to ensure a good connection to this planet.

_Brian

L1985 wrote: »

Ok so continuing on my electricity based education which I’m realizing is sorely lacking ....Earthers-I get that they are a metal spike into the ground but why do you need more then one? And why if it’s an earther it increases the efficiency but if it’s hitting off a pole accidentally it lowers it?
Also if I’m putting in more then on earther why should they all be in the same spot? And I’m getting from the above all have to be connected ? And why is more then one better? We have only one at home so looking at driving a second one based on this anwser!!
Btw you can see I was a fun child-I hate being told “because” and that’s my dads favorite anwser!!

Everywhere in your fence you have nice tidy joints, steel to steel.

But where your earth bar enters the ground you have a steel bar trying to make a circuit touching the earth around it, it’s inefficient.

And so the more earth you have the better overall circuit you will make.



It’s all relative to the size of the fencer you have too. You are trying to get a circuit that will accommodate the energy to go around the system.
So a battery fencer at say will require a smaller earth system compared to a large mains fencer which could be 10times stronger.

Nekarsulm

L1985 wrote: »

And why if it’s an earther it increases the efficiency but if it’s hitting off a pole accidentally it lowers it? !

Because those are two different and seperate wires coming from the fencer unit.
Its like leaving one lead off a battery, the clock/toy/whatever simply won't do anything untill the other lead is connected.

emaherx

L1985 wrote: »

Ok so continuing on my electricity based education which I’m realizing is sorely lacking ....Earthers-I get that they are a metal spike into the ground but why do you need more then one? And why if it’s an earther it increases the efficiency but if it’s hitting off a pole accidentally it lowers it?

You use more than one earth rod ideally spaced by 10 feet or more but connected by wire to the earth side of the fence. This is because electricity will find the path of least resistance, 3 rods 10 feet apart will cover 30 feet and will allow the current to return via multiple paths effectively lowering the resistance of the soil.

A metal post touching the line wire is a different situation all together. In a perfect fence with 0 faults the fence is completely open circuit meaning no current will actually flow until an animal comes in contact with the fence. So its about potential difference, the potential of the fence line wire is about 10,000V and the potential of earth is 0V so if you are touching both the ground and the fence you become the load and the current will flow through you and you will feel all 10,000V (especially if you are bare footed like a cow).

In the case where you have a metal post touching the line wire and the ground then you have just brought the earth and the fence line wire to the same potential as they are physically connected by a conductor meaning the potential difference is 0V ie no shock. Due to differences in resistance of the ground, metal post and the line wire there may well be some voltage but it will be closer to 0V than it will to 10,000V

L1985 wrote: »

Also if I’m putting in more then on earther why should they all be in the same spot? And I’m getting from the above all have to be connected ? And why is more then one better? We have only one at home so looking at driving a second one based on this anwser!!
Btw you can see I was a fun child-I hate being told “because” and that’s my dads favorite anwser!!

The earth rods need to be connected to each other and the fencer so for practical reasons they will be relatively close to each other but they shouldn't be too close either (at least 10 feet apart). There are many factors that determine how many earth rods are needed including power in fencer, area covered by fence and moisture of the soil. look at the table I posted the other day. There is no point using 3 1m earth rods with a 0.2 Joule fencer powering 1-2KM of fence likewise not much use having a 6 joule fencer and trying to fence in a 40 acre farm using 1 1/2m rod (however too many is better than too few). If you have inadequate earthing or an under powered fencer unit then you are already at a loss and that's before you add in unintentional earthing from vegetation.


What model of fencer are you using and how much fence do you need to power?

orm0nd

Using 6 earth rods here. 4 metres between each one and in a semi circle. Bonded with a continuous length of covered under ground cable with the insulation stripped at the clamps and covered with a few layers of denso tape.

Previously we had a very small stray voltage reading in the dairy {even with everything bonded} but above sorted it.

BTW our energizer (Electric Shepherd) is almost 40 years old and never missed a beat.

emaherx

orm0nd wrote: »

Using 6 earth rods here. 4 metres between each one and in a semi circle. Bonded with a continuous length of covered under ground cable with the insulation stripped at the clamps and covered with a few layers of denso tape.

Previously we had a very small stray voltage reading in the dairy {even with everything bonded} but above sorted it.

That's a proper job, what sort of area have you fenced?

On the stray voltages were your earth rods anyway close to the parlors earth rods? Or was the fencer plugged in to parlors sockets?

Nobbies

Some here have said when joining your earth bars together, use insulated steel wire. is this a must or is it just somewhat better than using steel galvanised fence wire???

i use the latter myself and current tests well.

Nobbies

Probably being said earlier in this thread but if you want to test how good or bad your earth is.
grip the earth rod/wire tightly in your hand,then put your other hand palm down on the ground

if your getting a shock/tingle your earth is poor.

emaherx

Nobbies wrote: »

Probably being said earlier in this thread but if you want to test how good or bad your earth is.
grip the earth rod/wire tightly in your hand,then put your other hand palm down on the ground

if your getting a shock/tingle your earth is poor.

To do it properly you should completely earth the live line wire too, so drop a good section of the wire to the ground temporarily or ground with a metal bar. Then use a meter on the earth rod anything over 300V is bad (most fence testers only go as low as 500V so any reading on them can be taken as bad)

The issue is if you just put up a brand new fence with 0 earths from vegetation etc then you won't get a shock/tingle from the earth system no matter how bad it is as the circuit won't be complete.

wrangler

Nobbies wrote: »

Probably being said earlier in this thread but if you want to test how good or bad your earth is.
grip the earth rod/wire tightly in your hand,then put your other hand palm down on the ground

if your getting a shock/tingle your earth is poor.

To test it that way you're supposed to earth the fence with laying an iron bar across the fence as well.

''Lay an iron bar across the wires, making a direct connection from the fence line to the ground. Then place your volt meter on the last earth rod in the line to see if there is any voltage between the earth rod and the ground. ''

orm0nd

Nobbies wrote: »

Some here have said when joining your earth bars together, use insulated steel wire. is this a must or is it just somewhat better than using steel galvanised fence wire???

i use the latter myself and current tests well.

Galvanise will rust in time if in contact with soil/grass. Conductivity is on the outside of the wire so it will lose efficiency.

L1985

Sorry guys was away yesterday so just looking at all this now.
That makes a lot of sense so thanks all for the above . I’m having awful hassle with our fence so I’m going to check the earther and put in a new one. I’m not sure of our brand I’ll check this evening when I’m gone. Jesus it’s a lot more complicated then you’d expect thou!!

ABlur

https://ibb.co/NZ1Cn3t

What is this reading telling me? My cheapo meter says 10000volts but what do the amp reading mean?

Nobbies

When fencer manufacturers say a unit will fence say 200 acres. what does that mean??if the mains unit was in the centre of a 200 acre block of land that it would be adequate for fencing round that 200 acre boundary and including lines inside that??

i myself intend to link up a outfarm with the mains unit.this outfarm would be the 3rd townland away from the mains unit at home.

i haven't yet worked out the distance this would be.so when i do figure that out if its within the distance a fence manufacturer say on a unit am i safe to say that unit will go the distance assuming good wire insulators e.t.c

Nobbies

orm0nd wrote: »

Galvanise will rust in time if in contact with soil/grass. Conductivity is on the outside of the wire so it will lose efficiency.

so would galvanised earth rod bars need replacing then too after aperiod of time?

emaherx

Nobbies wrote: »

When fencer manufacturers say a unit will fence say 200 acres. what does that mean??if the mains unit was in the centre of a 200 acre block of land that it would be adequate for fencing round that 200 acre boundary and including lines inside that??

i myself intend to link up a outfarm with the mains unit.this outfarm would be the 3rd townland away from the mains unit at home.

i haven't yet worked out the distance this would be.so when i do figure that out if its within the distance a fence manufacturer say on a unit am i safe to say that unit will go the distance assuming good wire insulators e.t.c

Probably 100-150 km of fence, usually the manufacturer states distance and acres but realistically these figures can vary massively between theoretically distance and real world depending on soil type/moisture and earthing along the fence and condition of fence.

Starchasers

_Brian wrote: »

There is also the issue of resistance at joints, leakage at insulators and the difference in wire types.
We have heavy steel wire at the permimiter but inside it’s a mix of steel tie wire and white. With the combination of earths, connections and potentially leaking insulators it’s massively complicated.

Power does strange things in lines that you wouldn’t expect.
Ever notice during a lightening storm lights dim occasionally ? That’s a strike on the grid, you’d expect a surge rather than a dim. But locally to the strike the burst of power temporarily lowered resistance in that section causing local power to flow towards the lowered resistance and the result can be a dip in power at other local locations.

I would never test one section of fence and presume the others are fine.


Obviously the use of copper wire to join sections is a big no no. Where the copper and steel wires join they are dissimilar metals on the presence of voltage and damp and so create an oxide film between them which over time insulated them from each other, causing a gradual drop in power transferred until eventually no power is transferred.

Just as regards a lightning storm, the dip in power is the recloser on the main line feeding your house, detecting a short circuit caused by a lightning strike of several million volts hitting a pole etc. 99% of the time, the recloser turns the power back on within a second which is where you see the momentary dip in the lights. The voltage caused by the lightning strike usually travels down to earth by means of a lightning arrestor which is an insulator at 10 or 20,000 volts but turns into a conductor at a million volts etc.

Your bang on about the dissimilar metals such as copper and galvanized steel etc. Aluminum and zinc (are beside each other I think on the periodic table) from the galvanizing react with copper in the presence of moisture. I’ve even had bad connections on aluminum conductor where every individual strand became insulated from each other because of salt water corrosion. Quality conductor and very good connections will see you right for a long time to come

Starchasers

L1985 wrote: »

Ok so continuing on my electricity based education which I’m realizing is sorely lacking ....Earthers-I get that they are a metal spike into the ground but why do you need more then one? And why if it’s an earther it increases the efficiency but if it’s hitting off a pole accidentally it lowers it?
Also if I’m putting in more then on earther why should they all be in the same spot? And I’m getting from the above all have to be connected ? And why is more then one better? We have only one at home so looking at driving a second one based on this anwser!!
Btw you can see I was a fun child-I hate being told “because” and that’s my dads favorite anwser!!

An earth spike by itself has a high enough resistance to the general mass of earth. A second halves the resistance, a third etc etc, you can’t spend enough time on your earths as it is where people do a short cut and forever suffer. Even if you dug a deep hole to get down to where it is damp earth all year, you could bury a coil of copper wire which is kinda pulled sideways to spread it out to get maximum contact with the damp soil. Again a boggy area will be damp all year and will make siting a fencer easier as regards earths

longgonesilver

One of the posters on here a few years ago said that he had installed his earth bars in the soakaway from his septic tank, so watered daily.

_Brian

ABlur wrote: »

https://ibb.co/NZ1Cn3t

What is this reading telling me? My cheapo meter says 10000volts but what do the amp reading mean?

Your meter is reading 5700 volts, is this good ? Well it depends on the size of the fencer, if it’s putting out 20,000v and you only have 5700 in the fence then you have a serious problem, if it’s a small fencer and putting out 6000v then having 5700 in the fence is good.

It’s showing a short to ground in the direction of the arrow to the left. I presume the 8 is some sort of scale as how serious the short to ground is, it maybe Amps but i don’t know.

Keep moving along and testing and it will bring you to he problem.

emaherx

_Brian wrote: »

Your meter is reading 5700 volts, is this good ? Well it depends on the size of the fencer, if it’s putting out 20,000v and you only have 5700 in the fence then you have a serious problem, if it’s a small fencer and putting out 6000v then having 5700 in the fence is good.

It’s showing a short to ground in the direction of the arrow to the left. I presume the 8 is some sort of scale as how serious the short to ground is, it maybe Amps but i don’t know.

Keep moving along and testing and it will bring you to he problem.

Definitely not amps, 5,700V at 8 amps would kill you before you reached the fence

A 2 second contact with 240v @ 0.1A is lethal.

_Brian

emaherx wrote: »

Definitely not amps, 5,700V at 8 amps would kill you before you reached the fence

Yea I’m a bit rusty but that was my initial thought.
I presume it’s jusr a scale of how bad the ground in the fence is in that direction??

I’ve never used that type of tester but have thought they must be handy.

emaherx

_Brian wrote: »

Yea I’m a bit rusty but that was my initial thought.
I presume it’s jusr a scale of how bad the ground in the fence is in that direction??

I’ve never used that type of tester but have thought they must be handy.

Actually just looked at the manual, it says it is current, but I presume they have left out quite a few decimal spaces to make for easier reading.

So a low single figure means fence is healthy. Higher current on line means there is earthing. In an ideal situation there is no current until fence comes in contact with an animal.

ABlur

emaherx wrote: »

Actually just looked at the manual, it says it is current, but I presume they have left out quite a few decimal spaces to make for easier reading.

So a low single figure means fence is healthy. Higher current on line means there is earthing. In an ideal situation there is no current until fence comes in contact with an animal.

Thanks for that. Fencer covers about 40 acres which is the max of what it is suited to. I find I sometimes get a high 'A' reading close to the unit and the earth bars whether it's due to earth or another reason I'm not sure. They are a handy if expensive gadget to have to locate a fault but I still rely on the quick fence tester to tell me I've voltage.

emaherx

ABlur wrote: »

Thanks for that. Fencer covers about 40 acres which is the max of what it is suited to. I find I sometimes get a high 'A' reading close to the unit and the earth bars whether it's due to earth or another reason I'm not sure. They are a handy if expensive gadget to have to locate a fault but I still rely on the quick fence tester to tell me I've voltage.

If you have faults on the line the reading will always have highest current closest to the unit as current has to flow from unit and back to unit but it may take various paths through different earths loosing power as you head away.

So if you have low current near unit and high voltage at end of fence you know you are in good shape. Real world fence on 40 acres will have some earthing.

Sacrolyte

Sorry to head of on a tangent but
Can of you guys recommend a switching adapter with an “app” whereby you can switch on/off your fencer(in this instance)and know weather it’s on or off instead of the older type that just switched on or off by texting it and you might not have known if it was
on or off and got Zapped.

gozunda

Sacrolyte wrote: »

Sorry to head of on a tangent but
Can of you guys recommend a switching adapter with an “app” whereby you can switch on/off your fencer(in this instance)and know weather it’s on or off instead of the older type that just switched on or off by texting it and you might not have known if it was on or off and got Zapped.

Even that is handy tbh. Do you have one that you'd recommend?

emaherx

Sacrolyte wrote: »

Sorry to head of on a tangent but
Can of you guys recommend a switching adapter with an “app” whereby you can switch on/off your fencer(in this instance)and know weather it’s on or off instead of the older type that just switched on or off by texting it and you might not have known if it was
on or off and got Zapped.

Could use a sonoff device if you have wifi near fencer.

https://sonoff.ie/sonoff/84-sonoff-s20-wi-fi-plug.html?gclid=Cj0KCQjw9JzoBRDjARIsAGcdIDU6Sbsg_OOe4pEHTINMiEVGgEieTjzKEkUyMkf5GmOzG2wdmxeMqtQaAhNBEALw_wcB

I've installed a few different integrated types to control roller doors and shed lighting. Remote control of shed lights is useful when using calving cameras, some times night vision is lacking with certain colours of cows.

Like this one for multiple devices.
https://sonoff.ie/sonoff/52-sonoff-4ch-4ch-r2.html

dar31

I've 2 elephant fencers both are the blue box type but fairly old. They are elephant M45.
Dose any know what out put they are. I've searched online and no mention of a m45. And there is no indication on the unit as to output in joules. Any ideas.

emaherx

dar31 wrote: »

I've 2 elephant fencers both are the blue box type but fairly old. They are elephant M45.
Dose any know what out put they are. I've searched online and no mention of a m45. And there is no indication on the unit as to output in joules. Any ideas.

Well the M40 is 4.0 Joules and the M115 is 11.5 Joules. I'd guess yours is 4.5 Joules.

dar31

emaherx wrote: »

Well the M40 is 4.0 Joules and the M115 is 11.5 Joules. I'd guess yours is 4.5 Joules.

Thanks. Makes sense when young see it.

dar31

emaherx wrote: »

What power are your battery fencers In Joules?many are designed for strip grazing (less than 1km of fence) and might be as low as 0.2 joules.

Here is a rough guide.

So over the farm split in 2 with a fencer on each loop. 150ac each and i measured the lenght of fence using an online tool giving me 15km of wire per 150ac so what size fencer should I be using.
Ideal scenario is one fencer doing the whole farm
On a good day I can maintain 2-2.5 kv on tester other times it can drop to 1.5 kv

_Brian

Hard to beat buying the largest fencer you can afford.
There’s no such thing as a fencer that’s too big and considering most last 20-30 years of service it’s a good investment.

emaherx

dar31 wrote: »

So over the farm split in 2 with a fencer on each loop. 150ac each and i measured the lenght of fence using an online tool giving me 15km of wire per 150ac so what size fencer should I be using.
Ideal scenario is one fencer doing the whole farm
On a good day I can maintain 2-2.5 kv on tester other times it can drop to 1.5 kv

You have issues with your current fencer/earth system or fencing 2.5KV is too low. 3KV is considered minimum but you should be aiming to exceed it. Anything below 6KV on a mains fence and I'd go looking for the issue.

So you have 300acres and only 30KM of fence. I certainly wouldn't go for the 3 Joule option as it bearly meets the requirements but any earthing on fence will quickly kill it. 6 Joule may cover your current needs but if you want to divide farm up further later you'll need bigger.

Truthfully I'd go with _Brian, you can't go too big, with the size of your farm I wouldn't consider anything under 20 Joules for a single unit. And plenty of earth bars 6 -8 it's a big area and your earth system makes up half of circuit

Pod123

Remember one time doing a Fencing repair job for a farmer. He has 300 acres approx divided in half by a narrow road.
Unplugged fencer and did a repair job on one side.
Back to yard and farmer says he will unplug fencer to do other side. I told him I had it unplugged he says I have a fencer for each side. Went in to see a second fencer a stafix approx costed about 600 pounds.
I told him I would get a stronger current using one fencer and would do the whole farm.
He used copper wire to galvanise wire as a feed and earth with one earth stake.
Replaced all the feed and earth wire with proper wire used more earth rods to eliminate leakage.
In the end that one fencer did all the farm and had better current.
Don’t spare the earth bars or using proper insulated wire.

gozunda

Anyone have or use the Gallagher S20 Solar Powered Fencer?

How good is it and what kind of distance will it cover?

wrangler

gozunda wrote: »

Anyone have or use the Gallagher S20 Solar Powered Fencer?

How good is it and what kind of distance will it cover?

It's .2 of a joule, I've a one joule here and it's very easy kill it
On the chart on post 50 of this thread it claims .2 joule will do 3 acres

emaherx

gozunda wrote: »

Anyone have or use the Gallagher S20 Solar Powered Fencer?

How good is it and what kind of distance will it cover?

What sort of area are you looking to cover?

I bought this one for a 20acre out farm
https://www.electric-fence.co.uk/voss-farming-set-12w-solarsystem-box-12v-green-energy-2872.html

Cheaper than the Gallagher and 10x the power. (Will cover 30 acres )

gozunda

emaherx wrote: »

What sort of area are you looking to cover?

I bought this one for a 20acre out farm
https://www.electric-fence.co.uk/voss-farming-set-12w-solarsystem-box-12v-green-energy-2872.html

Cheaper than the Gallagher and 10x the power. (Will cover 30 acres )

Thanks for that.

15 acre block with no mains access. I hadn't seen the table detailed earlier.

The Gallagher one doesn't look great tbh ..

Muckit

longgonesilver wrote: »

One of the posters on here a few years ago said that he had installed his earth bars in the soakaway from his septic tank, so watered daily.

Was me! I have since relocated the energiser and have the earth rods in the bottom of a nearby drain!!

emaherx

gozunda wrote: »

The Gallagher one doesn't look great tbh ..

Has a hefty enough price though.

Starchasers

Sacrolyte wrote: »

Sorry to head of on a tangent but
Can of you guys recommend a switching adapter with an “app” whereby you can switch on/off your fencer(in this instance)and know weather it’s on or off instead of the older type that just switched on or off by texting it and you might not have known if it was
on or off and got Zapped.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.ie%2Fulk%2Fitm%2F183765081350

I have this at home and by sending a signal strength request it’s possible that when you get a reply, you know the switch is alive (and could energize or deenerguze the fencer), sending an off signal switches it off if not off already. I use the signal strength request to show that the battery isn’t after failing etc

orm0nd

Nobbies wrote: »

so would galvanised earth rod bars need replacing then too after aperiod of time?

To a lesser extent yes, but keeping away from air slows down the process, hence I wrap the connections and any exposed part of the rod in multiple layers of denso tape.