Broken PEN conductor

[snipersmith87]

Attended a seminar today based on EV charging points. The broken PEN conductor was mentioned and converting to TT.

2 things.
1. How often does a PEN conductor go down?? My understanding was that they use PME to reduce this risk further.

2. I asked the question as to should we be installing class 1 external light fittings / exterior water taps (no plastic joints) on a tn-c-s setups with the same potential to become live in the event of a broken pen. I honestly dont think they knew how to answer it. They just fobbed me off. So am i missing something?? Surely the risk is exactly the same. We dont go and TT mrs smiths metal light fitting beside her front door??

 

[GBDamo]

I'll put money on it being in one of the amendments.

You're right though, should be done by the DNO, but I believe the reason it was included under the electricians scope of work, is to try an save money for the DNO who is already struggling to just maintain our national grid shovel enough money into the shareholders grubby mitts.

FIFY

 

[snipersmith87]

So what are we actually looking at ? When we come across a faulty PME

Lost/deteriorating N connection somewhere in the ground ? Or problems back at the sub station

Has anyone ever measured the touch voltage on a tingly tap during one of these faults

My thoughts too. I see Essex comment of 1 a day. Thats much higher than id have thought tbh. Interesting stat. I dont know of any incidents my way.

 

[Charlie_]

Zero incidents over here in the iom.
TNS & TT only
It’s a doddle

 

[Octopus]

Seen a few unearthed installations in my time ......... no one died or got hurt as far as I'm aware........

 

[Simon47]

My guess is that if you find it and it's not in the news, then it's a local issue with a failed joint. If it's a failed neutral at the substation then it stands a good chance of making the local (or even national) news.

Couple with two young children forced to flee their burning home after thieves cut power cables causing a massive power surge. - Copper Theft and Substation Safety - Cresatech

Four homes went up in flames and hundreds were left without power in sub-zero temperatures this morning after thieves cut through a cable at an electricity substation to steal copper worth just £40. One family, with two young children, was forced to flee their home in Greenock, Inverclyde, at...

www.cresatech.com

I confess to access to a little inside knowledge about goings on in my local DNO - and they are in a difficult position. As we all know, most substations are out in the open, and once down to the 11kV-415/240V local level are in practical terms unprotectable. Thieves will nick anything even if it is bolted down and typically without any appreciation of the risks they face or care for the problems they cause. On top of that, if someone does injure themselves, the HSE are on the case asking why they (the DNO) allowed it to happen
In the link above, someone nicked a few feet of neutral cable. I recall a similar case in Lancashire not that long ago where most houses in a whole street had similar issues when a neutral link was stolen from the exchange.
Things I've heard from my insider include a whole earthing grid ripped out from a 132kV substation; and them getting a cooling alarm from a substation, and the engineer arriving to find the last of the oil disappearing into the ground thanks to some **** having nicked the brass valve off the drain point.