On Wed, 12 Sep 2018 13:10:08 +0100, Martin Brown
wrote:

On 12/09/2018 13:00, T i m wrote:
On Wed, 12 Sep 2018 12:48:05 +0100 (BST), "Dave Liquorice"
wrote:

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

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?

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

https://www.ebay.co.uk/itm/RING-INSU...e/172138194030


That's exactly what we used Martin (and from the same supplier who we
can highly recommend for both prices and level of attention and help).
;-)

Cheers, T i m

On Wed, 12 Sep 2018 13:36:52 +0100 (BST), "Dave Liquorice"
wrote:

On Wed, 12 Sep 2018 13:00:56 +0100, T i m wrote:

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

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?

I was thinking more of a 4 to 6" length of fairly snug insulation
around the wire

Ah, ok, like some thin (i/d) silicone tube?

rather than a something like a bit of hose pipe
filling the hole and the wire flapping about inside.

That was one of my thoughts. ;-)

As has been pointed out the ring insulators are the thing to use.

And we did.

Note how they have that "finned" bit between the ring and metal
screw. That extends the path length.

Noted and understood (their function).

Does the wire *have* to go
through these holes?

Yes, *if* we are to retain the very convenient 'patio area' in front
and to one side of their main hutch / run.

Let me try to pain the picture. Mum has a rectangular garden , one
side grass, one side concrete with a concrete path down the middle.

The hutch is a wood frame double story jobby with the ground level
'run' (probably 6' wide by 5' deep x 2' high) with a rectangular weld
mesh stapled on the inside (in whole panels per side) and a wire roof
over back half.

The hutch part is the same width as the run, about half the depth, two
feet height and 2/3rds wire at the front (door / wall).

Previously, she had a modular panel steel frame and wire infill border
that ran about 3' clear across the front and down the left side of the
run part. The back of the run is close to the fence and the right a
plastic storage shed.

So, what we wanted to do is extend the front right of the run forwards
and the back left sideways sufficiently to give us something to attach
the patio barrier back to, but that meant the (4) wires that ran round
the run would have to pass between the hutch and patio where they met
at the b/l and f/r.

So as to minimise the direct impact on the hutch and increase the
distance of the wires from the hutch, we created 4 corner 'angle'
sections from untreated pine (44 x 28mm and 28 x 18mm + 28 x 18 and
110 'infill' or so) to mount the insulator rings on , coming off at
45 degrees from the corners and so to get the wires back round these
infill parts, we drilled 4 x 25mm holes though the middle, meaning the
wires were a good 40mm away from the patio frame and 60mm away from
the hutch.

The idea is that these corners only really need tacking to the hutch
as the wires will be like binding straps (but not that tight).

The door has it's own battens, insulated rings and wire and will be
joined to the man wires via a short section of 'drop cable' at the top
/ hinge (where the rabbits can't chew it).

The object of this exercise is to deter Mr Fox from lingering and
making nose that would wake the neighbours (at night).

If the run is open to the patio then the electric fence would be off
as the rabbits would be able to get out into it and of course Mr Fox
could also get in, although I'm not sure he would make it up the ramp
and into the bedroom, during the day with my Mum wandering about?

When in their lawn run they (should have) have their bunker. ;-)

Cheers, T i m

On Wed, 12 Sep 2018 13:14:16 +0100 (BST), "Dave Liquorice"
wrote:

On Wed, 12 Sep 2018 00:52:29 +0100, T i m wrote:

On the hutch we have there are shoot bolts, none of which open easily,
even for those of us with opposing fingers. ;-)

Shoot bolts, that's the description I couldn't think of yesterday.

It comes to us all sooner or later. ;-)

Provided they are pretty stiff they should be ok.

Like I said, we can hardly undo them! ;-)

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.

Understood.

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.

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:

I intended it to be the earth rod, which is in turn connected to the
energiser earth (in case that matters).


+---------- 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.

Ok.

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.

A.

The bunnies might not appreciate this if
they are running about over the mesh over the ground.

There is no mesh under their feet (not good for their hocks I
understand) so it would only ever be the real ground (in this case the
concrete).

So I saw it as:


+---------- wire --------+
| v v
Energiser v v
| v v
| ------- mesh---- v
| / v
| / Leakage
| / v
|/ v
+-earth -----------------+
---
-


?

Cheers, T i m

In message , T i m
writes
On Sun, 09 Sep 2018 08:38:42 GMT, DerbyBorn
wrote:



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

A house near me had a couple of coach lamps each side of the front door -
possibly 25watts.

Possibly originally 25W incandescent - now replaced by something close
to 25W LED?

Someone has bought the house and replaced them with god
knows what wattage flood lights. Looks horrid - dazzles people - stupid.

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

Some people have no respect for the countryside.
Google 'dark skies uk'
http://bit.ly/2MNIwTT
--
Ian