OT: How does power supply company locate a fault?

[newshound]

Well that is likely to be multiple faults at different locations, isn't it. Not implausible for a storm in a wooded area with many lines.

[charles]

There was a line feeding then Guildfords tv transmitter which suffered in this way. The land owner was asked to fell the tree to stop this happening

- so he did, but it fell onto the line and snapped it!

[The Other Mike]

Except there can be conductor damage, insulator string damage or salt contamination, a problem with tree trimming, a problem with blown debris that could be ongoing or a problem with anti-climb guards such that there is a charred body at the location of the fault. Those are some of the reasons why distance to fault is recorded as it happens.

Follow ups would be a line inspection usually from the ground if nothing is seen then a flypast with visual and thermal imaging equipment would be scheduled the next time the helicopters are in the area. The performance or otherwise of the protection systems in clearing the fault would automatically be reviewed within a few hours of the fault in every case.

Bad joints or cable degradation on more modern cable installations are detected by using an optical fibre in close proximity to the power cable to provide distributed temperature sensing, with a distance resolution of around a metre or two and temperature measurement within a degree C.

No operators routinely use 'time domain reflectometers' for HV fault location, very rarely they may used on cables particularly where there is a possibility of multiple faults.

[Jethro_uk]

Are they non-metered ? They must be metered - even if aggregated -

*somewhere* ?

Otherwise I know where my 'leccy is coming from for the rest of my life ....

[dennis]

That's when the man goes to the substation and holds the trip in to make it a permanent fault that they can find.

Done that around here twice in eighteen months, both times it was a fault where they had jointed a street lamp.

[Ash Burton]

Street lights on public roads are not normally metered. The owning authority pay a fixed fee per annum based on the lamp type. e.g 80w sodium etc

Otherwise I know where my 'leccy is coming from for the rest of my

[Tim Watts]

Do you think every streetlamp has a meter? Or a personal cable?

Former: not that I've ever seen when the cover's been off. Cutout and maybe a timeswitch (less common now with light sensors up top).

Latter: No they don't and I know that for a fact: a) my dad supervised jointers connecting the things - the go onto a joint on the main LV cable. They may take a couple of small cables off this for neighbouring lights). I've also seen this joint recently when the road's been up.

They charge the council based on some sort of estimation - that's all.

[Halmyre]

Our power went out at the beginning of December. Came home, darkness. Every one else in the street was fine, the consumer unit breakers were all on, no obvious signs of damage. The power bods came out and established that the fault was on the other side of the meter and hooked up a 'beeper'. Unfortun ately they were getting highly conflicting readings which put the fault any where within 6 meters (basically, still inside the house) to a few hundred metres. Eventually they picked an arbitrary spot, dug a hole and determined that the fault was under the entrance to our (20 year old) monoblocked dri ve. Rather than dig up the drive they cut a narrow trench in the road and b ypassed the break, which was a shame in a way, I was curious as to why it f ailed.

[Ash Burton]

Street lights on public roads are not normally metered. The owning authority pay a fixed fee per annum based on the lamp type. e.g 80w sodium etc

[Dave Liquorice]

It's always worth giving the DNO a call if you lose power for more than a couple of seconds more than a couple of times up to an hour or so apart. I've always found the call handlers of ENW to be friendly, helpful and knowlegable. ENW also operate a SMS service that alerts you to planned outages or provides fairly accurate updates about an outage. Including "it should be back if it isn't let us know".

[MM]

Me and the othr 217 properties affected.

That's why the power company sends a team out to cut any offending branches down. It's not rocket science!

MM