Lack of trust in tncs

[rich.250]

Hi guys,
In the past week have been to 3 call outs where customers are getting shocks of exposed extraneous and conductive parts.
Both because of loss of neutral in the supply. Well CNE conductor.
I think this is ridiculous. And the suppliers don't seem to be aware how dangerous this is.....
These are all separate problems and not because of one cause.
Has anyone had this so regular??
I agree it is a very good earthing system just if this keeps happening extra protection needs to be implemented

 

[rich.250]

Yes it does momentarily. Especially if there working on lines, they try to rely on it being PME. But there's always the odd house that has no neutral due to where they disconnect

 

[Engineer54]

Once a month?? Now that i don't believe for a New York second!!

 

[rich.250]

I could believe that in the sticks for
Sure. Although I'm beginning to believe it...

 

[JD6400]

I did think that as well but he then told me that they have a special lorry kitted out and they take along and try to fix the knacked appliances on site !
I promise you that i am not pulling your leg and the bloke did seem strait up !!!

 

[rich.250]

Saying that, I've seen them listening to Tarmac to try and hear a loose arching connection. We have no hope LOL!!

 

[Engineer54]

I did think that as well but he then told me that they have a special lorry kitted out and they take along and try to fix the knacked appliances on site !
I promise you that i am not pulling your leg and the bloke did seem strait up !!!

Don't you think that this wouldn't have become common knowledge by now, if these DNO's were repairing knacked appliances etc?? Let alone the public reaction to getting serious belts off any earthed metalwork in there houses etc... Rarely would it involve just one house or apartment, if a broken neutral was the cause. This guy may have seemed straight up, but i think he was more into telling stories to be honest with you.

When you think about it, ...Who would except a appliance repair, when damage was caused by an outside party, ...i certainly wouldn't, i'd want a replacement unit, ...pure and simple!! lol!!!

 

[ipf]

Saying that, I've seen them listening to Tarmac to try and hear a loose arching connection. We have no hope LOL!!

C*** tarmac these days!

 

[rich.250]

Yeh fair enough.
The places I have had trouble are remote, and the fault was each time only effecting one or two buildings.
In London I could see people being a bit wiser and switched on to it, rather than the rural farmers I deal with LOL

 

[JD6400]

Granted , when you put it like that !
I just do not see what he would off gained by coming out with what he told me ? But there again as the the saying goes " Theres nowt as queer as folk ! "
But i do still stand by the ones that i have personally found / seen .

 

[Engineer54]

Overhead systems have always been more susceptible to breakdowns, purely because they are exposed to the environment, ie storms, snow, tree falls, and high winds etc!! But even in those circumstances, it's still a rare occurance that only the neutral line is affected, failures tend to involve more than one line of an overhead system. Supply take-offs to overhead lines tend to be pretty robust, so even more of a rarity to see a connection fail....

 

[Engineer54]

As an added note, i have No miss trust of a PME supply. I have a TT system at my home in Cyprus that presently has an Ra of a tad under 3 ohms, that has been improving year on year from an initial 8 ohms. I would have no hesitation at all accepting a PME connection from the supply company there, if available, which it isn't. They only provide PME in the main towns where the local distribution TX's are generally located within the ground floor of multi floor housing blocks, and will generally supply 4 or 5 such blocks as well as a small amounts of businesses and shops etc...

Most of Cyprus, apart from the centre of towns etc is all overhead supply, which seasonally see's disruption etc, from downed poles from falling tree's etc. New estate type developments are now being supplied by underground supplies, but most will still not supply an earth connection!! That's mainly due to the supply company saving money, which is really a bit of a false economy in the bigger scheme of things...lol!!

 

[Phil]

one of the tutors from college has had a fair few appliances repaired over the last couple of years due to his pme supply and trouble with it. they have sent an electrical firm out to try to repair if possible washers computer and tv`s etc. he was that fed up after the last one he was on about banging a rod in

 

[Engineer54]

I doubt very much it's a problem with a broken neutral if he's had several problems. More like a supply that's prone to power surges... That's becoming one of the main problems the power supply companies are having these days, with them reinforcing some of the local distribution networks, and leaving others on the same smaller cables. ...Almost impossible to set protection relays on the MV/LV side to cover both the reinforced networks and existing networks...

As for accepting repairs caused solely by an outside party, he must be mad, ....if they are responsible for damage or knackering appliances within your home, i'd be wanting NEW, end of!! lol!!!

 

[Geordie Spark]

one of the tutors from college has had a fair few appliances repaired over the last couple of years due to his pme supply and trouble with it. they have sent an electrical firm out to try to repair if possible washers computer and tv`s etc. he was that fed up after the last one he was on about banging a rod in

Funny you should say that. When I was doing my 16th edition at college, the lecturer told us that in his view the best system was TT because you weren't relying on other folk - the DNO - to ensure its integrity.

Mind you, he also said that if you were fitting - for example - one of those B&Q type halogen security lights & there was no earth available for it, it was ok to connect the neutral to its earth terminal !!! :dizzy2:

 

[Engineer54]

Funny you should say that. When I was doing my 16th edition at college, the lecturer told us that in his view the best system was TT because you weren't relying on other folk - the DNO - to ensure its integrity.

Mind you, he also said that if you were fitting - for example - one of those B&Q type halogen security lights & there was no earth available for it, it was ok to connect the neutral to its earth terminal !!! :dizzy2:

Well that just about sums this lecturer up then, ..doesn't it!! lol!!!