Cause of frequent power interruptions: "livestock rubbing themselves against poles causing [circuit breakers] to operate" ;-)

I have heard of electrocutions taking place when an animal or a human urinates on a live cable or live electrified fence...... and presumably taking out a MCB or RCD.

I thought it might be BS, but maybe not. A large animal would exert quite a bit of force leaning on a pole and rubbing to perhaps relieve an itch. More to the point would be that the rubbing would probably be very regular, and if the frequency was perhaps close to some resonant frequency of the pole, it might move the pole and the movement increase with each rub the animal makes.

Would it be enough to cause a trip? I guess you'd only find out by watching an animal rub against one of the poles, and the chances of you observing that would, I guess, be pretty low.

Well well well, in todays news.....

Electrocution by an electric fence seems unlikely if it is a standard farming type as they have strict limits on maximum pulse energy and repetition rate.

John

Probably. Quite a few poles round me (also Northern Powergrid) are at rakish angles ~30 degrees off vertical and badly thinned at cattle neck rubbing height to the point where the next good winter blow will have them over. We had multiple failures during storm Arwen and they were absolutely useless at fault finding.

It is usually the HT lines that go down. We have had the odd one where a single phase has dropped too.

It might trip but it would take a very big bird. Pigeons and pheasants just end up dead on the ground if they hit 33kV cables in flight.

HT cables which are on horizontal layout (possible with the third phase raised in the middle) are uninsulated wire.

The main cause is that they no longer do preventative maintenance worth speaking of - they replace only on failure which is cheaper for them but lousy for their customers. You don't have much choice about the cowboys who provide the mains infrastructure though.

FWIW we had a 20 minute powercut today and they insisted that I went through their script and did all the checks even though I could see that both phases and all of the village was down by looking at the emergency lights on in the Village Hall! They did get power back fairly quickly.

No. I spent most of my childhood on the farm behind where we lived and watched this happening, and the wonderful bang as the ?600amp fuses blew at the substation at the top of the lane leading down to the farm.

During very hot humid weather the 11KV and above lines that criss- crossed the farm sagged so much it was quite 'interesting' to go under them while riding on top of a trailer well-loaded with bales of hay. Happy days. You could drive a tractor as soon as you could operate the clutch without sliding forward off the seat, usually about age 9.

HSE spoilsports have banned all the fun now.

Those saggy power lines sway even more if they are attached to a wooden pole and the ground has dried out and shrunk allowing the pole to wobble.

Indeed.

One of our dairy cows managed to jam its head behind the operator for an overhead 11kV supply (lattice girder pole). Removing the padlock allowed the animal to switch off the entire village.

I once saw a Crow flap its wings while standing on the crossbar of the same supply. Big puff of black feathers as it bridged the ceramic insulator.

There was this 11 years ago

It happened here last week. The problem was a cow scratching back and forward on the wooden pole, which is quite flexible and so was swaying slightly. Unfortunately the cow must have found the resonant frequency as the line swayed more and more until an arc jumped between the wires (halfway between the poles). This tripped the power, which came back on a few seconds later. The noise of the arc scared the cows away, and they seemed to stop scratching on that pole after that - the next pole along has a switch on it and seems to be thicker, so doesn't sway so much. Fortunately this week the cows are in another field (with no access to the power line).

Mike

Easy enough to tack a bit of barbed wire round the pole at scratching height.

NY snipped-for-privacy@privacy.invalid wrote

Don't buy that. Strong winds would have much more effect.

Nope.

No, but they aren't suggesting the poles are lose in the ground, they are claiming that the cattle are producing a movement in the pole thats above the ground. I have never watched any cattle doing that but I find it hard to believe that they can cause the pole to flex that much by doing that.

Ours are on the same pole with the 11KV lines at the top.

Never seen any birds fried like that.

You can get branches come off in a storm and short lines.

Correct.

Hard to see why the cattle story would be the correct one just for you lot.

But it can't be that because the inspector would be able to see the deat animal.

Its no news that cattle to rub against fence posts, power poles and trees.

What is hard to credit is that doing that to a power pole causes enough movement in the wires to trip a recloser.

They will rub up against almost anything but if it moves at all then they try a bit harder. Many electricity poles near me are thinned to half their diameter at cow shoulder height (after about 50 years wear).

We are talking about Northern Powergrid here. They have poles that are rotted at the base, loose in the ground and canted at rakish angles.

They don't do preventative maintenance like their predecessor NEDL did. They replace *ONLY* on fail. This meant that in storm Arewn last year entire runs of poles went down like dominoes after one snapped and the shock along the wires took down the next ones along.

Having started a discussion on my village's Facebook group, we've come to the conclusion that no-one can think of any fields around here that have cattle in them at the moment. Could be horses, though.

And how interesting that previous power cuts have been attributed to overhanging branches that had not been pruned before they got too close, and now they come up with a different explanation for the latest set.

Something is causing power trips that always occur at about this time of year (late summer / early autumn) each year. I'm excluding power cuts that have an obvious cause such as a thunderstorm or gale-force wind: we've had very occasional power cuts at times of exceptional weather.

What is interesting is that some people (maybe living further out of the village eg on one of the farms) sometimes get much longer power cuts, as if their power is tripping a circuit-breaker that does not have an auto-recloser at times when other people's power gets re-connected immediately. You'd think that knowledge of who was more severely affected might help the power company pin down the cause...

Anyway, we'll see whether the rerouting of the HV feed to the village has any effect.

NY snipped-for-privacy@privacy.invalid wrote

Not sure that horses do that rubbing much. They mostly give themselves a dirt bath instead.

Likely just some new loon with a new story which doesn't explain why other area dont get your high level of short term reclosures.

Bet Martin's story is the real one, f*ck all pole maintenance is being done and a decent wind moves the worst poles enough to see a reclosure.

Do you get more wind then ? Hard to see cattle rubbing more then.

Bet they are trying to bullshit you consumers about the gross lack of pole maintenance.

Oh yes, indeed out in Suffolk I happen to know they are replacing a lot of posts that are loose and have now rotted at ground level. Cows weigh a lot. Maybe the way forward is to provide cow back scratchers at the other end of a field. Are these the poles side by side with a transformer between them. Back in them old days when I could see, you could see those wobbling in the wind. At the time I'd not considered livestock, but it might have been as you only saw them passing in a train, and the double poles were where it seemed power was taken off for remote dwellings. Brian

As I said, the livestock thing is entirely plausible as animals change their coats quite often. Also the problem with wind and trees is because of the repeated contacts straining the cable and it breaks. Of course just a short way from here in Surrey a huge tree fell over and pulled several cables and telephone lines with it. Brian

Or an electric fence :-)