Do I need to test an old wiring installation?

[KingKenny]

Hello again everyone - I've been asked to assess a small old house pending the possible (ok, probable) replacement of the old CCU.

I've attached a composite picture of the two boards currently in place at the site. The new Wylex to the right was installed about 8 years ago and has circuits for Heating (Dimplex storage heaters), smoke alarms and heat alarms and so on.

The older CCU is a MEM (I think) with 6 ways, 2 5A (only one used) and 4 15A (only 2 used). No RCD or ELCB. It has an (I think) 6mm-ish unsheahed earth conductor and twin neutral and live tails coming into the unit from the meter.

I've climbed up into the draughty old loft and traced all the cables and have confirmed there is a single lighting circuit and three radial circuits to socket outlets in three different rooms.

The wiring is sponsored by luck it seems - The lighting circuit and two of the radial circuits are all routed through "custom made" JB's smothered in insulating tape. None of the lighting circuits have earth conductors, 1 of the radial circuits has an earth connection at one outlet, but not at another. 1 of the others has an earth connection, the other does not. In short, it's a mess.

My question is - How do I go about testing this installation (or do I even NEED to - should I just recommend the client gets an isolating switch/meter fitted and get the house rewired asap?).

View attachment 18668

 

[KingKenny]

I've noticed a few debates about this recently. I have an open mind on it tbh (as well as both 2.5mm and 4mm cable!). I get that the EU way is more biased towards radials, but ring curcuits aren't inherently unsafe are they? Don't both work fine if installed correctly? If so, then what are we really discussing? Saving copper for future generations? A tiny house on Skye ain't gonna make that much difference!

 

[stuartcourt]

after working all over Europe I do not listen to thing they have to say about anything electrical, our system is far better in every way, and quoting Tesco every little really does help the environment and 2.5 at 50p a meter you would only have to save 5 meters a day to save almost £500 a year on one type of cable (hope my maths right)

 

[dave1064]

Its all personal preference really. If you are wiring in twin and earth then 4mm cable is hard to come by.

A Ring works better as if a cable is damaged the sockets are all still connected.

I would always wire a ring circuit instead of a radial.

 

[mselect]

Rewire ASAP is the only conclusion based on your info. Custom made JB's are a recipe for disaster! Don't go there, just get it rewired!

 

[dave1064]

Rewire ASAP is the only conclusion based on your info. Custom made JB's are a recipe for disaster! Don't go there, just get it rewired!

I think we have already came to this conclusion. You are basically repeating what I said earlier

 

[Engineer54]

But you have to be sure the conduit system meets the requirements of Reg 543.2.2, Reg 543.2.6 and reg 543.2.7

In a commercial/Industrial setting I would not rely on it due to the possibility of external influences damaging the conduit and perhaps causing a break in your protection, and most conduit systems in domestic premises from my experience years ago tends to be the old rolled type and is not continuous in a way that would satisfy the regs.

You've got to be joking here surely??

Industry and commercial installations have been relying on metal containment systems long before even i came into this industry. I was brought up on large industrial installations, where the whole kit and caboodle was metallic containment. Not a single CPC to be seen within those extensive containment systems, and not once have i ever seen a low, or loss of Zs values.


What is it with modern day electricians, thinking they know better than the long proven methods of providing more than just adequate protection, both mechanically and electrically?? I haven never seen a well designed and installed external galvanised conduit system circum to normal external influences, where it no-longer provided mechanical/electrical protection. Granted, in an environment where corrosive atmospheres are prevailing, standard metallic conduit would not be suitable. But in general terms, only MICC will out last a good galvanised containment system, ....and you can take that to the bank!! (or perhaps not in today's troubled times...lol!!)

Not all domestic installations used the old ''split conduit'' but i would agree with you, on your point concerning that type of conduit. The only modern day conduit system i would use a separate CPC, is the Yank EMT (think that what it's called) electrical tubing. That stuff relies on grub screws for it's connections!!

 

[KingKenny]

Hello everyone - Just to let you know that I tested the existing install as best I could, explained to the customer what, in my opinion, was required and he's agreed that a rewire is required.

 

[Geordie Spark]

Hello everyone - Just to let you know that I tested the existing install as best I could, explained to the customer what, in my opinion, was required and he's agreed that a rewire is required.

Good lad.

That should keep you out of mischief and in beer money for a few days.

 

[KingKenny]

Heh heh ..... Yep - I'm looking forward to getting stuck into this one - it'll be the biggest all round job I'll have attempted so far, although not as 'pain-in-the-arris' as wiring combi-boilers to room stats - That is without QUESTION a dark art.

 

[KingKenny]

Oh boy ....

 

[telectrix]

is that black sheathed cable VIR?

 

[KingKenny]

is that black sheathed cable VIR?

Yep, These JB's had a mixture of old rubber cables and PVC. Various csa's going at random to lights and switches. They are now in a bin liner ready for the tip.

 

[telectrix]

weigh in at local scrapyard.

 

[Andy78]

Yep, These JB's had a mixture of old rubber cables and PVC. Various csa's going at random to lights and switches. They are now in a bin liner ready for the tip.

D: That's your beer money mate !

 

[Geordie Spark]

Oh boy ....

View attachment 18920View attachment 18921View attachment 18922

WOW!! ........... You could display those pictures in the Tate gallery and win prizes.

They're quite artistic in a modernist sort of way ...........

 

[Stroppy]

Shouldn't this be in "show us your installs!"

 

[KingKenny]

what startled me was the rose in the kitchen. black as night and burnt to a crisp on one side. 2.5mm conductor running to it. The light was still operational, circuit protected by a 5A rewireable fuse. An 80 year old woman lived alone there until recently.

 

[Geordie Spark]

what startled me was the rose in the kitchen. black as night and burnt to a crisp on one side. 2.5mm conductor running to it. The light was still operational, circuit protected by a 5A rewireable fuse. An 80 year old woman lived alone there until recently.

An old lady who I did odd jobs for died recently aged almost ninety and lived in the same house for most of her life started asking me if I thought her house needed a rewire.

It was very borderline, but there was no way she would have survived the upheaval that would have been involved as she was suffering from cancer & everything else, so I told her it would be ok for a while yet - and it would be - but now she's gone it's somebody else's headache.

 

[Outspoken]

Yep, These JB's had a mixture of old rubber cables and PVC. Various csa's going at random to lights and switches. They are now in a bin liner ready for the tip.

Rubber and PVC....you KinkyKenny you!!