ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Direct Burial vs Conduit?

I understand there's a new marker tape soon going on the market which is intended to go under the cable or conduit.

It's going to be marked with "Warning: You have just cut through an electrical cable!"

All distribution stuff here has to go in red ducting. No direct burrial anymore.

Nice one Pauluk. I've heard that the new marker tape you mentioned is available with Braille writing.Handy for when the flash has rendered the shovel-users eyes inoperative.

As for "flexible cords pulled through garden hose". That is actually a step up from "flexible cord buried direct".

I think everyones in agreeance though that only armoured or screened cables should be "buried direct". No matter what the regs say.

P.S. If the budget allows, then use conduit pipe. A buried screened cable may fail safely, but will still need to be dug up and repaired. This can be very costly and may be avoided with the use of a few bucks worth of conduit pipe duing installlation.

The problem is the wiring rules tell us that.......

Wiring systems installed underground shall be identified by an orange
marker tape complying with AS/NZS 2648.1.
The marker tape shall be
—
(a) positioned not more than 200 mm above the wiring system or any
additional mechanical protection provided;

[This message has been edited by Dapo (edited 03-11-2006).]

[This message has been edited by Dapo (edited 03-11-2006).]

It also states that a marker tape is not needed for orange conduit. I can't understand why they decided that. It appears they only considered someone manually digging it up rather than by mechanical means.

There is a proposal for the next edition that marker tape is always installed and placed at approx half the depth of cover.

Sometimes it doesn't matter what markers and warnings are provided.

Back when I was at the BT satellite station, there was one time when they had outside contractors in to dig foundations and other trench work for one of the new dishes and associated buildings.

One of the diggers was stopped just in time to avoid his shovel going through one of the site's 11kV distribution cables (fortunately one that wasn't energized at the time, but he wasn't to know that).

When hauled in front of the manager and asked why he didn't stop when he hit the huge marker tape with "DANGER High-voltage cable below" emblazoned in gigantic letters along it, his reply was, apparently:

"Oh, yes, I saw that. I didn't think it was important."

No, not really. About the only thing I know about it is it's yellow plastic.
Supposedly a gas company employee one said that after ten years under a busy street that kind of pipe is as flat as a pizza... still they keep installing it. Our gas mains leaked in five spots on a distance of 15m...

From RODALCO:




A lot of new cables now these days go in pre drilled heavy duty conduit.
These will have no warning strip above it, If a digger scrapes the ground it will possibly not break the conduit and therefore not damage the cable.
These methods are used extensively in Auckland now in OHUG programmes and for 11 and 33 kV feeder upgrades.
These feeders are laid in the middle of the road and manholes provided for termination joining pits.

Some of the protective strips I've seen here actually go together like a jigsaw. I _think_ they were from the cable company, but they might have been phone too (the phone lines were laid in 1992 when I was 7, and the cable not much later).