Can a monkey cause a fault on a 66 kV overhead line without being killed? 1

[SA07]

Hi
We had a tripping of SEL 311 relay on our 66 kV line. LED C,G, 87 were on. We did an inspection on the line. We saw a monkey sitting on a ceramic isolator on a pole. Please see picture below.

When it saw us, it moved down. Later we found damaged on 2 isolators and had to replace them.

Can the monkey be the cause of the fault without being killed? It did not seem to be wounded either.

 

[RedSnake]

My first question is which of those isolators on the picture where damaged?
From the picture it's seems that the monkey isn't large enough to reach between the wires ​in most places maybe between the 2 topp ones.
It might have been able to reach between the line and the pole.
Then it depends on how well the pole is grounded.
Maybe the isolators where damaged from earlier and the monkey climbing on theme made something happen.
The current will take the easies way to the ground so if it went through the isolator when it was sitting on it, it would not have been any potential difference within the monkey, only between the line and the pole through the isolator.

But there is many ifs here. ;-)

But it is a nice photo and a new problem here we only get this sort of problem with eagles and owls.

Best Regards A


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[jghrist]

Could it have been a monkey that died and was carried away by a scavenger? That could be the cause of damage to the other insulators, but more than likely would cause only a burn mark instead of permanent damage.

 

[jraef]

I have seen several instances where animals (usually birds as RedSnake says) have caused flashovers and have NEVER seen one survive, let alone unscathed, even at lower voltages. It seems implausible to me. But I would buy the idea of a scavenger carrying off the charred remains and maybe that monkey was the mate, hanging around not understanding why their partner is gone. I know gibbons mate for life, but that one appears to have a tail, so it wouldn't be a gibbon. I don't know if other monkeys mate for life, but I also don't know if that's a requisite for them to miss a partner and hang around grieving. I once had a crow take out the transformer feeding my house. After they cleaned up the mess and replaced the fuse, the crow's mate was hanging out on that pole and even on the same transformer, squawking, for almost a month before finally accepting it and moving on.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[JezNZ]

Working at a mine site we had a possum (the Australian animal) in a switchboard cause a 33kV flashover. 3 times. Survived the first two.

 

[3DDave]

I agree with the others - it's possible one or more monkeys got obliterated at that location and the remains rapidly recycled and this monkey is just hanging out where its buddies were last seen alive.

 

[RedSnake]

Well with birds at least here if they have a great wingspans they usually get the wings between to two cables.
Smaller bird can sitt and rest on the cables no problem and squirrels use them as motorways.

Where it is sitting in the picture no problem, it is isolated and even if touching the cable it would not be a problem neither touching the pole.

My hunting teacher ones in his youth shoot a crane, he regretted it deeply afterwards, it's mate stayed on screaming and calling for its partner the whole summer until fall.

BR A


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[RedSnake]

Ones we hade a German mouse that got electrocuted, we decided it was German because we saw it the first time during the installation in electrical cabinet, they where all delivered from Germany.
And then a month later poof the whole machine went dead, and there it was on topp of the incoming bus bar, main breaker hade tripped.

/A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[bacon4life]

Birds sometimes drop objects onto insulators leading to flashover. With birds it is usually either poop or nesting materials, though occasionally birds also drop fish on the lines!!! Perhaps a monkey could have dropped a large conductive object from the upper insulator onto the lower insulator?

 

[JezNZ]

As bacon4life said, over here we've had an entire 220kV grid sub go out thanks to a stream of bird poo.

 

[cranky108]

If a racoon can survive a 115kV (67kV phase to neutral), then it is possible a monkey will survive.

Then again, my old company had a place that would get squirrels, and a meter reader saw it happen. Where a squirrel fell to the ground and a cat ran and grabbed it,and ran off.

Large winged birds do have the span to get between a conductor and the ground wire.
Or they have been know to drop a snake across that span.

However if a racoon survives, it usually becomes very mad, and will chase anyone who comes into the area.

 

[crshears]

I too have seen raccoons survive 115 kV faults often enough for it to be statistically significant; ditto for squirrels on lower voltages. I'd sometimes swear / theorize that the critters had hair of an inversely conductive characteristic,. i.e. the dirty hair on the outside has crud and contaminants on it which seem to more readily conduct flashovers, especially when it's drizzling, whereas the hair closer to the skin is much more dielectric. I wish I'd taken some pictures of the burn tracks I've seen on the survivors; the pics wouldn't answer the marveling question of "how is it possible?" but they would definitely prove that it is.

I can affirm cranky108's assertion about faulted raccoons being unhappy campers; presumably the burn tracks hurt a little, which makes them somewhat irritable and best avoided, and pity the poor animal control officer or contractor who is detailed to snag them and transport them off site so they don't cause another trip . . .

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[cranky108]

Usually it is the serviceman who arrives at the substation first, that gets the angry raccoon to chase them.

 

[LittleInch]

It doesn't take much to find evidence that so long as it doesn't breach the gap then it's ok.

Those wires look far enough apart that it could swing on one wire without getting zapped.
NOTE. Don't watch to the end if you're squemish.
e.g.

https://www.youtube.com/watch?v=FsVMloLCRCU

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Artisi]

LI, looks like lunch for the locals.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)