What earth does my folks house have?

[OllieNotts]

Hi, I had a wander down to my Dad's cellar today to have a look at his earth system as we have recently done t-t, tns and tncs etc at college and wonder if I should be concerned that he has none
His only earth cables running from the cu are 2 what look like 4mm earth cables running on his very wet water pipes. I thought t-t was an earth running to an earth rod and the main supply has black and red cables running out and a spare space for what I would imagine the earth cable would run into to create a tncs?
Anyway it was re-wired about 15 years ago so I wouldnt know what regs were in place or if it would be common practise then. Also found an interesting junction box in his work room with no lid on and the wires quite poorly terminated(only in my opinion going but when my work has been ripped out at college lol) it's as if the spark forgot to put the top on. He has never noticed it, and we don't know if it is live but obviously I wasn't going to touch it just in case as it was running along to another junction box that was cover and had a good amount of t&e coming out of it.
Anyway can uploads pics soon as I realise how, I guess it is common place in the domestic world just thought I would share and get your opinions.
Also lastly, just wondered what the conservatory R1+R2 is all about? He had a spark in 8 years ago who mentioned something about he had to work around things to install the required sockets and light he wanted but just let him get on with it. Why would you write it on the cu?

 

[WPD Lad]

Could do with a full pic of the DNO cutout, could be a few things

 

[plugsandsparks]

Also cannot tell from the photo but one way or another there needs to be a connection from the CU earth rail back to either an earth rod, bonded to the armourings of the incoming cable from DNO or to the DNO head, if the only earth cables coming from the earth rail are to gas and water then it may be missing, suggest get a sparky in to quickly check if something is missing.

 

[needasparks]

As others have said need a bigger shot of the head. If you can't see an earth from the bottom or side of the sevice head I would have said from that photo and from what you have said its a TT but using the water pipe as an earth rod.
Not uncommon from the age of the head as it looks cast so prop 1930's with a poss 60amp cutout but if that is the set-up you will need it upgrading. Best to get a sparks out to assess as i would think If your lacking main earthing to that degree then It may pose a major problem.
However you also say it was rewired so i would hope this was picked up and corrected and it just is not in the photo's.
Post a bigger pic of all of cutout and all of CU and it may then be seen.

 

[oldtimer]

Ok I will have a stab
Picture 1 is a junction box it looks like someone has broken into a power circuit to supply another socket
Picture 2 is your main incomer supply from your electricity supplie
Picture 3 is an earth bond on to a water pipe my guess is this is the main supply coming into the house not sure if the lead pipe is the supply from outside or it is a part of the plumbing.
Picture 4 R1+R2 did your parents get a conservitory installed recently ie in the last 10 years ? and if is the case then go back to picture 1 and see if one of the cables go to it

 

[nickblake]

Looks like a TNS to me well just got that feeling looking at the top of the cut out that you can see ,as the other guys have said better picture would confirm ish having said im asuminge that above the fuse is the meters , and ill find that im totally wrong lol

 

[trev]

Just out of interest Ollie and since you've looked at earthing systems in college. what do you think it is?

 

[needasparks]

Just out of interest Ollie and since you've looked at earthing systems in college. what do you think it is?

Damm, why did i not think of that. Oh the shame.............

 

[OllieNotts]

Just out of interest Ollie and since you've looked at earthing systems in college. what do you think it is?

Well I could not find any earth coming from the bottom of the meter, the only earth cables in the whole cellar are the two running to the water pipes so I instantly thought that it was just an old system that could be safe but outdated i.e no major earth running in to the mains or to a rod just clamped on to the pipes "like in the old days" I think it was tt using water pipes as earth rod? Defo no rod under ground. That is why I had to look on here, one of my tutors went to a house recently and told us it can be common in house with old fuse boards but my Dads is quite new(15 years not new but not really old) and also he did the zs test and found a reading of 0.8ohms which is acceptable but he has obviously arranged for a proper earth to be fitted by the authorities. So it got me wondering is my Dads the same. His cu looks ok no major dramas everything is t&e coming out of it, it is a 1920's house so the guy who said 1930's was very close to the mark.
I can find no earth cable meeting N anywhere to make tns although I may be wrong it's all about learning in it On my cu in my house I can see the earth coming out the bottom of the cu where as I cant here. I can take more pics next time I go round if it is of interest no problem.
My folks have the house on the market and are typical of the "if it hasnt broke yet why get it looked at" so they said they will leave it for the next owner lol. Cant wait to get in to a house like this with someone who knows what they are looking at so I can get more knowledge I understand it will be hard for you guys.

 

[needasparks]

The force is strong with this young jedi.......Keep the enthusiasm Ollie and you will do well.

 

[nickblake]

just a couple of corrections ollie it will be Ze not Zs that your lecturer measured ,and TNS has a max permited of 0.8 Ze is the external loop inpedance and Zs is after the consumer unit on the circuits , if the earth is connected to the Neutral then it will be a TNCS and not a TNS , not being picky but being corrected is the way you learn , have a look at where the cable enters and see if any earths come off the cable outer sheeth , or does the supply come in on 2 cables keep up the learning

 

[OllieNotts]

just a couple of corrections ollie it will be Ze not Zs that your lecturer measured ,and TNS has a max permited of 0.8 Ze is the external loop inpedance and Zs is after the consumer unit on the circuits , if the earth is connected to the Neutral then it will be a TNCS and not a TNS , not being picky but being corrected is the way you learn , have a look at where the cable enters and see if any earths come off the cable outer sheeth , or does the supply come in on 2 cables keep up the learning

Ah fair doo's I thought) Zs=Ze+(R1+R2) and that is what he was working from maybe I just got confused Can you not see the earth connected to N then if it is in the box?
I just assumed you'd be able to see it like when it is attached to the DNO it is pretty obvious?
The supply cables are one big red one and one big black one that's it. I am gagging to learn more just need someone to give me a brake
In the mean time I will keep asking folk who's houses I enter to look at their main supply to see what is going on

 

[Knobhead]

Get a full photo of the service head and the incoming cable.

I’m going to be a right wet blanket here. The centre of Nottingham is notoriously bad for earth rods. When building the Victoria Centre the EMEB had to drill over 100’ deep to get a decent reading and that was using Bentonite infill. They had to go below the water table of the Trent. Have a look for Nottingham geology on Google.

I am assuming with a screen name ollienotts you are from Nottingham?

 

[OllieNotts]

Get a full photo of the service head and the incoming cable.

I’m going to be a right wet blanket here. The centre of Nottingham is notoriously bad for earth rods. When building the Victoria Centre the EMEB had to drill over 100’ deep to get a decent reading and that was using Bentonite infill. They had to go below the water table of the Trent. Have a look for Nottingham geology on Google.

I am assuming with a screen name ollienotts you are from Nottingham?

I am indeed, will take some pics on a camera instead of my phone hopefully it will make it a bit clearer.