Working On The Lines

[securespark]

Just going down the M56 towards Chester and seen some guys working on the lines with cradles suspended between the pylons.

Not quick enough for a picture, sorry, but what a great sight!

 

[Echo the husky]

They were changing a few insulators locally recently, using a similar access method.

 

[JBR]

Just going down the M56 towards Chester and seen some guys working on the lines with cradles suspended between the pylons.

What's the safe distance from the conductor, or anything at the same potential, to anything earthed? About six feet?

 

[Taylortwocities]

Thats the way to do it!!

 

[Lectrician]

What's the safe distance from the conductor, or anything at the same potential, to anything earthed? About six feet?

Depends on the voltage, and on skill level. Trained engineers can work as close as 60cm to energised 33kv.

 

[bernardgreen]

"Low" voltage ( only a few kV )

and when there are a few more kV

either way the pilots are extremely skilled.

 

[JBR]

Depends on the voltage, and on skill level. Trained engineers can work as close as 60cm to energised 33kv.

Thanks. I suppose it might also depend on weather and humidity levels too.

It's just that I remember a bloke telling me, years ago, about a colleague who climbed down the ceramic insulators supporting the live cable. I don't remember all the details, but I remember him saying that he was OK whilst hunched up, but when he began to stretch out to lower himself (or it might have been to raise himself up?) he felt 'something' (I can't remember how he described it) and had to go back.

To be honest, it sounds a bit far fetched that men could have to access the cables in that way. I thought they might have turned off the power and isolated the cables.

 

[John D v2.0]

Well, fun to be in your own equipotential zone! No need for safe isolation then.

 

[bernardgreen]

I thought they might have turned off the power and isolated the cables.

Blacking out a town or small city is far more expensive in penalties than is the cost of insurance and "danger" money for the workers.

 

[securespark]

Just looked on the Nat Grid map and it must have been Frodsham. The lines run very close to the 56 there.

As for safe isolation, I think Nat Grid can isolate certain parts of the network but I don't know how.

 

[JohnW2]

As for safe isolation, I think Nat Grid can isolate certain parts of the network but I don't know how.

One assumes that they must be able isolate any part of the network if they have to. There must be some jobs (like replacing a cable?) which surely could not be done live?!

It's at times like this that I am reminded that we miss westie.

Kind Regards, John

 

[securespark]

It's at times like this that I am reminded that we miss westie.

Indeed. Read one of his posts the other day and thought of him.

 

[sterowley]

Just looked on the Nat Grid map and it must have been Frodsham. The lines run very close to the 56 there.

As for safe isolation, I think Nat Grid can isolate certain parts of the network but I don't know how.

Im pretty such I've watched a program about them changing the isolators, With the big 6 conductor ones they just shut down the half there working on. Nowadays with modern H&S and the fact the grid has redundancy and alternative grid routes the won't be taking silly chances.

 

[JohnW2]

Blacking out a town or small city is far more expensive in penalties than is the cost of insurance and "danger" money for the workers.

I thought that the HV network was like the Internet - designed so that there were multiple possible paths between every "A and B", such that any one segment of the network could be lost without anyone's supply being interrupted?

Kind Regards, John

 

[bernardgreen]

designed so that there were multiple possible paths between every "A and B"

I was told the design was originally based on HV ring mains such that one section of the ring could be isolated for maintainance without losing supply to anyone. The two sides of the ring were often carried on the same 6 wire pylon route.