Earthing rod

[Barry Cade]

Here's one that'll make you laugh then cringe,I was doing a replacement RCBO consumer unit for an old wylex rewirable fuse unit on a TT system recently, when I came to tracing out and testing main earthing conductor to earthing rod and was having trouble finding it(the rod that is)I could trace the bonding conductors to the water and gas but the main earth disappeared into the fabric of the building and I couldn't for the life of me find the rod,when the customer came home from work I told him of my problem and he said "Oh its in here" and proceeded to walk around to the back door to garage,I thought oh its in a corner buried under stuff and I haven't spotted it,he went into garage reached into a cupboard turned around with the rod in his hand and said "here it is" and handed it to me,I said to him "Thats supposed to be in the ground with an earth cable attached to it" to which he replied "Well when I had the extension built it was in the way,so I took it out,,,,,,I connected the wire to a copper pipe though!" I said to him "It doesn't work like that,how long has extension been built" he said "20yrs" you should have seen his face when I told him he didn't have an earth to his house for that long.
I know he sort of had one with the gas pipe being buried,but thats not the point,he did have a voltage operated elcb but that was faulty and didn't work,and they are a pile of pants anyway,and his water pipe that he had reconnected the earth to had been changed by water auth. to hep2o plastic from his stop cock to the main stop cock in the road so not really sufficient there either.
What I found under floorboards would make your hair stand on end too,2.5 T/E stripped bare with flex feeding sockets twisted,yes twisted no mechanical connection around the conductors and just taped joints,2.5 T/E run through 15mm copper tube with the burr still there cutting into insulation making copper tube live(heating engineer job,they couldn't get cable across landing without lifting floor boards at top of stairs,so put it into tube to fish it across and just left it in tube,QUALITY),kitchen sockets screwed directly to wooden panelling no back boxes so a fire risk,wall lights wired in 0.5mm bell flex spurred off again twisted connection to radial socket circuit,strappers between 2 way switches using twin and earth with earth conductor utilised as a live switches in metal boxes so not earthed,all the radial socket circuits were on 30a fuse wire and multiple 20amp j/b's that had so many cables in them they looked like spiders.Every day when he came home the cost to sort it out had gone up and it got to the point when he said "Do you go looking for stuff" I did think about punching him at this point but instead told him "No but in the process of moving sockets and adding sockets as he had requested me to do and in testing I find this stuff, which I have to fix or disconnect the circuit as a legal and moral obligation if they constitute a risk to life" he did agree for me to finish work and make it safe and he did pay me but wasn't very happy bunny when I told him it was that or not have any electric in his house.
Just put this thread up to be a warning to anyone,be careful of what you quote,tell them if you find anything wrong(and you will find stuff if house is of any age and a hobby sparks has been at work) you will have to fix it or not liven circuit up,another tip I will pass on I always take photo's of the bad stuff on my phone before I tell them what I've found,just so they don't think I've made it up and creating work(LOOKING FOR IT!)
Hope this has been informative and I haven't been teaching my Granny to suck eggs Ha!
PS TT systems should be banned,electricity boards should change them to TN-C-S the Ze and Zs on TT's is atrocious no matter what the resistance I always fit RCD's or ELCB's on TT's,and I think I might fit RCBO's on every job now I've done this job.

 

[GLENNSPARK]

Tried that Mike. I've lost the will to live now though. I'd like someone to give me a valid reason for fitting a SP RCBO in any situation. The regulations are flawed, so don't try saying Reg. No. XXXX says so and so. The laws of physics don't change because the IET have bogged up writing the regulations by not taking N>E faults in to account.

i dont see the problem with split load configurations as well tony....
cheaper and RCDs are DP....

 

[MDJ]

Can't argue at all Tony, you have a very good point about RCBOs, I don't use them much, I do a lot of caravan site work and I use double pole RCDs not RCBOs, on a different note completely, I find it hard to make a dist board look neat with RCBOs in them, the silly neutral lead takes up a lot of space and makes the board look tatty haha

 

[Engineer54]

Personally, i can't see any problem using SP RCBO's on any TN installation. No different than the use of SP MCBs and fuses that we have been using for god knows how long. Any argument i can see against their use, would be on a TT installation.

 

[Knobhead]

Correct me if I'm wrong, isn't the idea of earth leakage protection to disconnect from the cause of the fault? Oh look there's a hefty fault flowing in the neutral, I'll turn the line off instead.

 

[Engineer54]

I'm not going to get into a war about the merits of TT and TNCS supplies, both have their advantages and disadvantages as we all know but out in the sticks where the supply authority provides no low impedance method of earthing there is still no alternative to an earth electrode, and if the ground is damp and its protected from mechanical damage it's fine. Same goes for the old voltage operated ELCB-in their day they were fine. I still come across domestic and agricultural installations that still have them in service, like anything else, if you test them regularly,they do the job they were designed to do.

Were they indeed?? So tell us, how do you regularly test those older VOELCB's, pushing the test button?? lol!! Those VOELCB's needed a tester that injected 50 volts into the system, so do you happen to own one?? I haven't seen one, for some 30 odd years now!!

 

[Engineer54]

Correct me if I'm wrong, isn't the idea of earth leakage protection to disconnect from the cause of the fault? Oh look there's a hefty fault flowing in the neutral, I'll turn the line off instead.

Well if you have an all RCBO CU, each unit will be only looking at the circuit it's protecting, so disconnecting the line to that circuit, will indeed stop the hefty return fault flowing in the neutral. I'm not saying i disagree with you in the principle of having the neutral switched/broken in a SP RCBO, and as i say, they are available now from one or two manufacturers.

 

[Knobhead]

If we follow the argument on. Why not have a SP RCD? Same difference.

 

[Engineer54]

If we follow the argument on. Why not have a SP RCD? Same difference.

Not really, because RCDs tend to be looking at several circuits rather than just one!!

 

[Knobhead]

One circuit or twenty circuits, there's a fault on one. Where is the difference?

 

[Engineer54]

Well unlike the RCBO's that only look at the circuit it's connected too and won't be affected by the other RCBO protected circuits, the RCD will, and why they are a pain to trace leakage faults. But they are DP, if SP the neutral fault problem you outlined above will be a problem.