Electric fences?

[tabbypurr]

the teddy bears can be pretty wild round here

NT

[T i m]

Thanks.

Cheers, T i m

[DerbyBorn]

?You must be the only person who can aim a PIR Lamp low. Most are aimed to light up the sky.

[T i m]

Well, Mum has two (we only have solar PIR 'lamps' that you can just see by), one on the front of the conservatory and that has quite a long 'peak' and I set that to basically cutoff by the bottom of her (not particularly long) garden and one fairly high on the garage set nearly facing downwards over mostly her parking area (and some of next doors).

We used to have one on the house opposite that was set nearly horizontally! ;-(

Cheers, T i m

[DerbyBorn]

A house near me had a couple of coach lamps each side of the front door - possibly 25watts. Someone has bought the house and replaced them with god knows what wattage flood lights. Looks horrid - dazzles people - stupid.

[T i m]

I have seen similar a few times and even with lights in the gateposts on the road where it ruins your night vision as you drive past. ;-(

Nearly as bad are people parked up on the wrong side of the road at night with the dipped beam dipping straight into drivers eyes. ;-(

Cheers, T i m

[Dave Liquorice]

often is

The ground under the concrete won't be very dry... Or are you thinking of foxy having all four paws on the dry concrete and nose on the fencer wire. Noses are sensitive.

The earth return doesn't have to be very good. Even if you need 1 mA to flow at 5 kV thats 5 mega ohms...

[Dave Liquorice]

If the hutch is fox proof, a short, even straight length of something for them to have access/egrees through would probably do the trick. A foot length of 110mm soil pipe? Securly, very securly, attached to the hutch with a sliding and latchable panel to shut them in at night. Design of the latch is the hard bit if foxy has access to it.

How good the rabbits are at scarpering into their bunker might be a problem if foxy got into the run and rabbits started panic. If they took fright with foxy still outside the run they'f probably go straight into it. Note the "bunker" needs to be where they normally go to feel safe. You can't give 'em a choice.

[Brian Gaff]

Exactly, these people who put on these electric shows know all about this, huge voltages, nice sparks and possibly a little burn ihere and there, but no current. Brian

[T i m]

Do we assume that rabbits can get through holes that foxes cant? The problem with that is stopping them making the access holes bigger. ;-)

Because we put them inside I got a cardboard box and cut a tunnel shaped one in one side (and put some straw in etc). The next day we noticed they had cut a new hole in the opposite side. ;-)

Yes, they have various lengths of plastic and fabric tubes to play in and I think even the biggest can fit though the 110mm diameter stuff (that's quite heavy duty).

Ah. There are two scenarios here Dave. They have a two level 'hutch (4 x 2 x 2') over run' (4 x 4 x 2') on concrete that has a sort of external 'patio' (also on the concrete) that they can be let out into if the weather is a bit iffy (they can come and go in and out of that as they please).

On the lawn they have a modular steel mesh panel pen that can be moved about (wear leveling) that they often get put in for the day if the weather looks bad.

Yes, I understand they can be quite 'cunning'. ;-)

Understood.

It's funny ... if my sister comes round with her whippets and they are let into the garden they do go a bit crazy (running up into their upstairs and thumping etc) whereas if daughters friend turned up with his Alsatian, one of that rabbits in particular will go nose to nose to him though the outside pen wire. ;-)

OK.

If their lawn run is up one end of the garden it can be incorporated with a open fronted hutch (their summer house, sat on concrete slabs) but it wouldn't offer any special protection against foxes. I was thinking of making said lift - outable bunker in there or, making sure the summer house itself was fixed down to the slabs securely and had a secure but removable front on it (so we could get them out ourselves) that could include the anti-fox access tunnels.

We picked up the electric fence stuff today and are in the process of electrifying the ground level of the main hutch / run, mainly to deter the fox at night and the resultant noise waking the neighbour(s?).

There is generally someone around during the day when they are in their pen and as long as they have their 'bunker' that should be enough. The main fear was Mr Fox coming back in the night, now he knows there are some rabbits about.

Cheers, T i m

[T i m]

Agreed, but I was wondering about the path though the ground to the surface of the concrete?

That's one of the scenarios. We have looked up the wire heights for foxes and have set them at 100, 200, 350 and 500cm from the ground.

We are hoping to link and ground all the hutch mesh (it's mounted to the inside of the frames) so that there should be a good path between the external wires and real ground (along with the path though the concrete that might give Mr Fox a slightly lower power shock).

One of daughters friends and was good (stupid?) enough to try some stuff out for us today.

Wit the earth rod pushed a few inches into the lawn and him standing quite close to it in his rubber soled shoes, he could actually hold onto the live wire (he said it was uncomfortable but bearable)

Taking of one boot and standing on the (dry) grass with one socked and one boot made him jump (he couldn't hold onto it).

Taking the one sock off made it more noticeable still, even touching the wire with his trousered leg made him jump (again, worse with the bare foot leg).

With the probe poorly in the ground by the edge of the concrete and him on the concrete, the effect was at it's weakest with him in his boots. With daughter in a socked foot, also on the concrete and holding one of his hands whilst he touched the live wire, they both felt it quite well. ;-)

If he touched the earth probe with his other hand he got the full whack and that did make made him jump! ;-)

We have yet to convince him to test it with his nose (ala Mr Fox).

Cheers, T i m

[Dave Liquorice]

How many foxes have you seen wearing wellies, bare foot is closer to what foxy will get.

Presumably the lads hands were also dry, not moist like a nose...

[Dave Liquorice]

something

trick.

Foxes can't get down a rabbit dug burrow. The burrows around here are about 4" dia, 110 mm waste water pipe might be 1/2" larger. But burrow size will vary with rabbit size.

The rabbits rather than the foxes? Yes, rabbits do like make holes in panels a comfortable size to get through but generally stop once that has been achieved.

Perhaps it would be easier to construct a say 5" square internal a bit over a foot long. Foxy might be able to get his head into that but not his shoulders. I think a foxes set has tunnels 6 to 7" dia. Close the entrance end with a thick bit of board with a 4" dia hole, edge of hole aligned with internal bottom tunnel board and let the rabbits cut it to size.

Not so much cunning but they'll "worry" it. Proding, pushing in every which way taking advantage of any movement they get, eventually they'll get it open. They'll then have a rough memory of how they did it, so will be quicker next time...

[T i m]

Hence my suggestion why he did that for the test. ;-)

When we got all the gear we were advised to ensure the wire was spaced well away from anything.

When we got home we did some experiments and ran the voltage along two parallel conductors on an insulated surface and had to get the conductors to within just a few mm of each other before the gap was jumped. Even laying the conductors on rainwater soaked wood didn't allow the voltage to be discharge though the wood till the conductors were 10mm apart.

So, in two places the wire passes though the middle of 25mm diameter holes, drilled though the wood and we are hoping that should provide a sufficient air gap to ensure no arcing, even when it's all wet?

I was wondering, if it did arc, if a short length of plastic tube (silicone?) threaded over the wire and though the hole in the wood would help, or would that make matters worse when it was wet?

Cheers, T i m

[T i m]

Understood. Daughter has three rabbits atm. A small albino hare looking thing, a medium sized 'Lion Head' and a larger 'lop' with helicopter ears (that was rescued from a breeder by the RSPCA). If the large rabbit can get though something then the others will also.

Yes.

So it seems (apart from the odd additional adjustment).

That's a good idea. Rabbit d-i-y! ;-)

We understand that the wooden turnbuckles are a definite no-no and the metal ones not a lot batter (especially if they aren't tight). On the hutch we have there are shoot bolts, none of which open easily, even for those of us with opposing fingers. ;-)

Daughter gave all the new pine woodwork (corner pieces to carry the electric wire insulated screw in loops plus end stops for either side of the door (the door will have it's own sub section, joined to the main wires by a short length of the 'lead out' cable) and battens to hold the insulated rings on the door itself) a coat of low VOC(?) paint (the nearest she could find to something that was recommended as animal safe) and weather permitting the Mrs and I might put all the parts on and wire it up tomorrow for her while she's at work.

The idea is to ensure all the mesh that lines the inside of the main run under the hutch is earthed together and to the main ground earth (forming a Faraday cage if you like) and so if Mr Fox tries to paw the wires / mesh he will find a very good earth, even if it's all very dry.

I'll try to take some pictures when it's done.

Cheers, T i m

[Dave Liquorice]

At the voltages involved it'll leak long before it arcs. Arc's are a "bad thing" not only will they reduce the "kick" they'll make the tick tick tick RF interference much worse.

Any insulator that makes the path length longer from the wire to ground will reduce the chances of arcing.

[T i m]

Ok. We were measuring the voltages on a tester all the time and couldn't really see any noticeable drop in voltage, other when it was arcing.

Understood ... 'spark sending apparatus'. ;-)

But that's the thing, whilst it might make it longer it might make it easier to traverse? eg, Would 10mm of (damp even) air offer more or less resistance than the 50mm long plastic tube filling the hole that is soaking wet with rain?

Cheers, T i m

[Martin Brown]

Hot electric fence wires usually get mounted on insulated standoff rings if you want them to be reliable under wet and windy conditions. eg

[Dave Liquorice]

Shoot bolts, that's the description I couldn't think of yesterday. Provided they are pretty stiff they should be ok. A hasp and staple "locked" with 1 1/2 circular turns of thick stiff wire with the gap in the overlap less than the staple dia ought to defeat 'em.

Hum, I think you're worrying to much about the earth return. Also attaching the mesh to the energisers ground terminal is quite likely to make the mesh "live" relative to real ground as well:

+---------- wire --------+ | | Energiser | | | +---------- mesh | | | Resistance Leakage to earth | | | +---------- earth -------+

The leakage current causes a volt drop across the resistance to earth lifting the mesh above earth. How far the mesh is lifted depends on the amount of leakage. Worst case is a short (arc's are effectively shorts) to earth, which will push the mesh right up to as near as damn it the wire voltage. The bunnies might not appreciate this if they are running about over the mesh over the ground.

[Dave Liquorice]

I was thinking more of a 4 to 6" length of fairly snug insulation around the wire rather than a something like a bit of hose pipe filling the hole and the wire flapping about inside.

As has been pointed out the ring insulators are the thing to use. Note how they have that "finned" bit between the ring and metal screw. That extends the path length. Does the wire *have* to go through these holes?