Electric Fence Specs

[daveob]

Am looking at having an electric fence installed around our property.

Any advice on specs, etc so I don't get BS'd by those quoting ?

Our property boundery is 50% pallisade fencing ( and drive gate ), the rest is pre-cast concrete walls. On the pre-cast side, 60% is on a slope, with a drop in height of about 1,5 panels for each horizontal panel.

So what should I be looking for ?
Best way to connect the drive gate to the rest of the fence ?
Thickness / quality of wire, insulators, posts, etc ?
Battery backup ? Specs of 'controller' ?

Totally clueless at the moment, so need to be educated by those of you in the know.

[Just Gone]

Your best energizer on the market is a Merlin or a Wizord 4 - Both these units have battery backup. If this is a normal domestic application I would recomend 1.1mm galvanized braided wire which is quite difficult to cut with a normal sidecutter. The fence itself should not be less than 6 strands. Reason for this is if you had to use 5 strands, you are only monitoring 2 lines, whereas with 6 strands you monitor 4 lines. Some people prefer to go full size with precast wall and palisade because it is possible to break the precast and / or bend the palisade pales to gain entry. You should use galvanized poles - either square tube poles or flat bar poles - some people again prefer the square tube poles because they think that you can bend the flat bar poles - I have never had this. Do not go for round bar - they are the cheapest and give the most hassle - the bobbins on a round bar crack after a while causing shorting of the live wire thro the bobbins. There are a number of ways to connect the sliding gate - the best is with a heavy duty in-line gate contact which cuts the live when the gate closes and completes the circuit on top of the gate when closed ie if the wire is then cut on top of the gate it will activate the alarm. A sliding gate contact series also works but only takes the live wire to the gate.

Do not have too many poles too close together - the whole idea of an electric fence is to warn you of an intruder - if the poles are too close and they put a blanket over, it will not let the wires touch and therefore the alarm will not activate. Ideal pole gap is around 3.5m - 4m.

Hope this helps for now. Am more than happy to help if/when you have more questions as you go forward with the project.

[Martinco]

Kevin................for the price, will stainless not be better ? The reason is that my fence is now 8 years old and the galv braided wire has rusted to the extent where the strands are breaking one after the other. The difference in price is not that great. Admittedly, you cannot get the same distance with stainless than what you can get with galv. but in my opinion it could be worth your while to go for stainless.
Other than the above I agree 100% with your suggestion.

[daveob]

Many Thanks Kevin

OK, so I have a Q/A spec sheet for the quote so far as follows :

Energiser :
Make
Model
Battery Backup Y/N
Battery running time
Battery type / size for replacements
Alarm output signal Y/N
Separate alarm signals for shock and cut ?

Earthing Rods
Quantity
Spacing
Length
Material

Wire
Thickness
Type ( stranded / solid )
Material ( Stainless / Galvanised )

Strands
6 or 8
Quantity of Live wires / Ground wires

Poles
Round, Square or flat bar
Material
Bobbins Material
Bobbins life span
Spacing ( 3.5m pref )

Gate
Heavy Duty inline contacts ?
Underground link between gate posts


Warranty on each component of the system.

[Just Gone]

@ Martinco - stainless is also good and you can get the distance with a good energizer. There was a problem a few years ago whereby the galvanized wire that was done was a very bad batch - you probably got some out of that .

[Just Gone]

dave - send me the quote that you have been given and I will have a look at it. I cant do anything with the above without knowing distance of fence and if it is walltop or full size.

[Martinco]

@ Martinco - stainless is also good and you can get the distance with a good energizer. There was a problem a few years ago whereby the galvanized wire that was done was a very bad batch - you probably got some out of that .

My luck !!!!!

As it is now I have to redo the whole fence.
Also the contractor that did the job overtightened some of the bobbins with the result that many of these started cracking where the bolt goes thru the bobbin. These I am replacing as needed..............but still a schlep !

[daveob]

dave - send me the quote that you have been given and I will have a look at it. I cant do anything with the above without knowing distance of fence and if it is walltop or full size.

Thanks Kevin. Will do once I get some - am just making a checklist first of what I should be wanting.

[daveob]

Hi Kevin

OK. Got the first 2 quotes in.

Kept the Specs the same for both

Wall-top.
Energiser M28 - 8 joule, 2 zones
143 meters ( 36m palasade, 15m flat wall, 92m on slope )
Square Bar
6 strands
extra 2 strands on 2 sections ( 46 meters each ) where wall is on a slope ( to cover the gaps in the steps of the wall )
2 x 20m HT cable and conduit ( from energiser to each zone )
12 core comms cable from garage to house
Keypad / control unit
Heavy Duty Gate Contacts
Buried cable across gate posts
Earth Spikes
Sundries

Price R 20664

[Just Gone]

Great specs, but seriously wouldnt go for a M28 ..... far too big for that distance. An electric fence current is like a water pipe - if it is such high pressure with such a short distance it is busting to escape - so any little rain it might short out to something if too close. An energizer that size you would use on a 5km complex.

That price is very high - I would charge 143m x R50 per metre = R7150.00
Energizer - around the R5000.00 mark
Cabling, conduiting trenching around the R1000 mark

Total: R13150.00

Not entirely sure how many gates you have but you can add around R500 per gate plus R400 per gate contact.

This is for a 6 strand fence as you have stated with square tubing.

[Martinco]

Sorry........I am not trying to hijack the thread !

Kevin,

What do you suggest in this scenario:

A 5 km fence that forms part of a complex with two energisers powered by solar panels and split in the middle with one energiser for the one 2,5 km section and the other eng. for the other 2,5 km.
Now the problem is that the Solars and energisers are out in the area that has no houses yet and the "guys" keep on cutting the fence and stealing the solars.
There is an alarm fitted that is in radio contact with the guard house but the distance is simply to great for the guard to react in time. By the time he gets there the guys are long gone !
The nearest point of the total 5 km fence to the guard house is +- 500 m. but still out of sight.
Could it work that the energiser/s be moved to the guard house and the HT leads be routed via a conduit pipe to the nearest point and the fence be connected as one fence ( all 5 km ) ?

[Just Gone]

Cant you install the solar panels high up on a 6 m pole, then protect the pole and the panels with either electric fencing / glass or ...... there are many ways ?

[Martinco]

Yep...........that was done but they simply cut down the pole. ( and break the panel in the process )

I simply do not see any other option but to move the panels and energiser/s to a safe spot.

[Just Gone]

Yep...........that was done but they simply cut down the pole. ( and break the panel in the process )

I simply do not see any other option but to move the panels and energiser/s to a safe spot.

Why not build a structure that they cannot get onto ? Build a brick building or build a pillar out of concrete. Or install a pole similar to the light poles on a highway.

Moving the energizers would be the last resort, but cabling and voltage drops would have to be considered.

[Martinco]

Why not build a structure that they cannot get onto ? Build a brick building or build a pillar out of concrete. Or install a pole similar to the light poles on a highway.

Moving the energizers would be the last resort, but cabling and voltage drops would have to be considered.

The developer is not keen on building another structure to facilitate this.
In your opinion, putting HT thru the cables for 500 m would work ? This is honestly the only solution I can come up with provided it is feasible ito. voltages.