Cable jointers, a risky job!

[Newboy1996]

My mate had his mains cable replaced as I told him there was no sheath on the existing one
The DNO came out and replaced cable back as far as his neighbours supply(under eaves). Splitting sheath, (fork style) to joint it and NOT isolating the street!

What safety gear do they use to do this work and how many get ZAPPED each year accidentally?

 

[RF Lighting]

They have special tools, and normally wear insulated gloves and a face mask.

The majority of distribution jointing is done live.

They have very strict safety guidelines, and I would imagine the accident rate is very low.

 

[streetlighter]

seen the DNO or there contractors do loads of live jointing on single phase supplys to street lighting columns.
One time the jointer had the live cable wrapped up in his sweater on his lap whilst stripping the new cable.
Also seen them use termianl strip on the joint which is covered with heatshrink.

 

[efiste2]

Live cable jointing is very common as RF says, but they work to a comprehensive set of DNO safety rules. Working on new plastic cable live isnt that difficult, as its all shear off and cold shrinks these days, But as you say, working on the old PILC cable (paper insulated lead covered) is much more of a skill. especially on the bigger MAINS. A good experienced cable jointer, especially LV and HV authorised, can make a lot of money.

 

[Newboy1996]

What kind of cable would they have used, it was a tiny diameter compared to my old TN-S supply. They have an old style cut out and meter?

 

[RF Lighting]

Probably a straight concentric cable.

It looks roughly the same size as 2.5mm 3 core SWA.

It will possibly be a 16mm cable like this:

 

[Newboy1996]

Thats the one!
Where's the earth, neutral, live?

Earth= armour
Live= centre
Neutral= ?

 

[securespark]

NOT isolating the street!

Where would they isolate from?

 

[Newboy1996]

NOT isolating the street!

Where would they isolate from?

Maybe a soil covered throw switch found in the first house's front garden

 

[securespark]

That cable pictured by RF is straight concentric. It is used for TN-C-S supplies.

The C and S of the supply type indicate "Combined" and "Separate".

Basically, the bare wire you see is a combined neutral & earth conductor.

It is "Combined" until the point of the cut-out, but from that point on, you can see that the neutral & earth are then "Separate".

 

[Newboy1996]

That cable pictured by RF is straight concentric. It is used for TN-C-S supplies.

The C and S of the supply type indicate "Combined" and "Separate".

Basically, the bare wire you see is a combined neutral & earth conductor.

It is "Combined" until the point of the cut-out, but from that point on, you can see that the neutral & earth are then "Separate".

Umm? If neutral is a "live" conductor, how is it the main earth wire does not have a chance to also become "live".

Might as well call the earth the "Safety Neutral Wire", if its essencially the same?

 

[securespark]

Maybe a soil covered throw switch found in the first house's front garden

Reminds me of the time I worked on a house in Chorlton, Manchester. This estate was one of the first built with electricity installed from day 1.

I was changing a CU when there was a knock at the door. It was a Norweb engineer, asking if my power was off.

"Yes, it is - I'm doing a board change..."

"So that's why the street has gone off..." replied the Norweb bloke.

Turned out the electricity company had looped the feeds from house to house, but instead of connecting the loop on the mains side of the cut-out, had done it on the fused side.

So when I pulled out the main fuse at number 3, numbers 5, 7, 9, 11 and 13 all went off, too.

Oops.....

 

[Wontdothatagain]

Out of interest i looked on the HSE webb site and i could not even find a breach of the regulation letalone a prosercution and i think this goes back to 1992

 

[securespark]

With respect to what?

 

[Wontdothatagain]

of someone being shocked while live jointing