Power cables are now normally ducted for new instalations. There is also a colur coding system. The main ones are listed below:-

That's correct. Emphasis on the now part though. But FTTC is generally retro fitting so most of the services to be altered won't necessarily be.

.....but the power utilities seem to get away with it under their own guidelines.

My cabinet has just had a duct driven under the road for the power to the cabinet. The trench either end are open with the LV supply cable visible and awaiting the jointing team.

Three guesses what the duct colour is? You may use your text books.

Edit: By the way, I'm not having a dig at the utility jointing guys (no pun intended). I've been in the electrical contracting game for 20 years. It's a dangerous way to make a living and they do a stirling job.

Edited by mrnelster (Sat 26-Mar-11 09:56:00)

"sterling".

Stirling is in Scotland. No doubt there are utility staff doing stirling jobs there, but ... .

In reply to a post by mrnelster:

Three guesses what the duct colour is? You may use your text books.

My NRSW licence has long since expired, but reality is there's always the possibility of a difference between what should be installed and what is.
The recommendation from the NJUC is that either red or black is acceptable. Installations should also be covered with a yellow/black marker tape approx 6" below the surface.

......but reality is there's always the possibility of a difference between what should be installed and what is.

And as with all industries thats exactly what happens.

We would install all cabling below ground as armoured, min 450mm depth, blinded with sand before compaction and black/yellow warning tape 6-8" below the finished level. Not everybody does however.

I remember back in 2001 a utility company changing supplies from overhead to underground in a street in Buckinghamshire. The concrete paths were lifted but no further excavation. The cables were then laid in black plastic ducting directly onto the old path's oversite and the concrete path replaced.

The concrete will protect the cable from a spade or fork. But the ducting won't protect it from a jackhammer! That's why many sites generally state no forks to be used on site by groundworkers, only spades.

In reply to a post by mrnelster:

......but reality is there's always the possibility of a difference between what should be installed and what is.

And as with all industries thats exactly what happens.

We would install all cabling below ground as armoured, min 450mm depth, blinded with sand before compaction and black/yellow warning tape 6-8" below the finished level. Not everybody does however.

I remember back in 2001 a utility company changing supplies from overhead to underground in a street in Buckinghamshire. The concrete paths were lifted but no further excavation. The cables were then laid in black plastic ducting directly onto the old path's oversite and the concrete path replaced.

The concrete will protect the cable from a spade or fork. But the ducting won't protect it from a jackhammer! That's why many sites generally state no forks to be used on site by groundworkers, only spades.

The standard is folowed for new work but there is lot of old stuff to no standard. Many power cables were armoured and just buried. It does of cause not make it easy for them to be seen when digging up roads etc

In reply to a post by Bob_s2:

In reply to a post by paul1360:

I not saying that power cables have to be run in ducting at all. But I have seen power cables run in ducting,conduit etc many times, in fact have done it my self back in the day.
What I was saying is that I'd been told that the new cabs were put in places that made the job easier for the firm and not BT, hence in the wrong place.

iechyd da

Power cables are now normally ducted for new instalations. There is also a colur coding system. The main ones are listed below:-

Red - Electric Power

Orange - Telecoms

Yellow - Gas/oil

Green - Sewers & Drains

Blue - Drinking Water

Red duct is only used in TTTC situations and even then very rarely, it is normally black. There is no pre-requesite for ducting but is more convenient as the highway is dug up for a shorter period and makes cable installation easier as the duct can be installed back filled and the cable pulled in at a later date with only jointing positions re-excavated.

In reply to a post by Bob_s2:

In reply to a post by mrnelster:

......but reality is there's always the possibility of a difference between what should be installed and what is.

And as with all industries thats exactly what happens.

We would install all cabling below ground as armoured, min 450mm depth, blinded with sand before compaction and black/yellow warning tape 6-8" below the finished level. Not everybody does however.

I remember back in 2001 a utility company changing supplies from overhead to underground in a street in Buckinghamshire. The concrete paths were lifted but no further excavation. The cables were then laid in black plastic ducting directly onto the old path's oversite and the concrete path replaced.

The concrete will protect the cable from a spade or fork. But the ducting won't protect it from a jackhammer! That's why many sites generally state no forks to be used on site by groundworkers, only spades.

The standard is folowed for new work but there is lot of old stuff to no standard. Many power cables were armoured and just buried. It does of cause not make it easy for them to be seen when digging up roads etc

Funnily that's why the utilities keep records of cable, pipe etc locations. It is an offence to dig up the public highway without the correct information.

Red duct is only used in TTTC situations and even then very rarely, it is normally black. There is no pre-requesite for ducting....

And pulling into ducting for power is more difficult than comms. The larger cable sizes don't go through ducting as fibre or multi pair does. I've yet to see one blown through.

And power utilities often have to joint or repair cables. They can't build a new access chamber every time, which means any chemical joints are installed external to the ducting. You can't pull a bullet through the ducting.

I assume that damaged comms lines would have the affected link rewired and joined at an existing access chamber? Wouldn't imagine a buried comms joint anyway.

Edited by mrnelster (Sun 27-Mar-11 16:32:00)

Aye, hauling EHV cables needs a bigger winch .
Have plenty of buried comms joints next to EHV feeders
Yes, DNO's do have their own comms networks, I have cables over 100 years old in my network and still going strong. Jointer's hate them, all paper and lead