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

 

[oldtimer]

So if I wire one property that has different conditions to another one that was wired at the same time then no matter what 25 years it has to be rewired ? makes you think why did we no install conduit in every property where it would have taken a day to rewire with no fuss or disturbance

 

[Dave 85]

I'm very suprised noone has commented on the fact that the wylex board in the photo appears to be a 17th edition high integrity board with both RCD's swapped for main switches suggesting the (apparently NICEIC registetred) installer couldnt get the RCD's to hold due to IR faults or perhaps borrowed neutrals or even an incorrectly wired CU and decided the best and safest option was to just get rid of the pesky RCD's. Incredible.
A slightly more clued up cowboy would at least have had the sense to identify the IR failed circuits and put just those on the main switch side or stick circuits with shared neutrals on the same MCB/RCD.
Believe or not I used to work for a guy who used to swap out RCD's for main switches because he didnt know how to make high integ boards work. He was fully apprenticed 2360 level 3, NVQ 3 AM2 and Elecsa registered.
That was around the time I decided I should probably work for myself.

 

[gnuuser]

definitely test first and be sure to make the home-owner aware of problem areas or improper repairs or installs.
stress that its their safety and compliance with codes that influence their your decisions.
they will usually be more in tune with your suggestions.
consumer safety and code compliance is the reason why our training is so strict

 

[GLENNSPARK]

you know it my customers are in for an almighty shock lucky 25

but honestly....
what was said before about needing rewiring after 25 years was just the biggest bunch of old horse shyte....
obviously he hasn`t grasped the effects numerous faults can have on the dielectric strength of cable insulation....
now, if he had any sense at all he would be looking at the BS3036 fusecarriers (if the install had a board utilizing these)...have a look in em....see how much splash is in there....that will give a good indication as to whether its been clearing loads of fault which in turn can be a good indicator of how the cable is (not always)....the more fault`s have been cleared...the less the IR on the final.....and thats before you even get the IR tester out....

 

[GLENNSPARK]

So if I wire one property that has different conditions to another one that was wired at the same time then no matter what 25 years it has to be rewired ? makes you think why did we no install conduit in every property where it would have taken a day to rewire with no fuss or disturbance

but some of these statements from the uninitiated are getting a bit demoralising old...

 

[GLENNSPARK]

definitely test first and be sure to make the home-owner aware of problem areas or improper repairs or installs.
stress that its their safety and compliance with codes that influence their your decisions.
they will usually be more in tune with your suggestions.
consumer safety and code compliance is the reason why our training is so strict

if on an ECR...you start by sampling 10%...any crap you up it to 20%...and so on...
as far as testing the install is concerned...you test the lot to the current edition of BS7671......
this is how you prove whether ..or not the install is good for continued service....
not some magical figure like 25 years plucked out of the clouds....

 

[GLENNSPARK]

I'm very suprised noone has commented on the fact that the wylex board in the photo appears to be a 17th edition high integrity board with both RCD's swapped for main switches suggesting the (apparently NICEIC registetred) installer couldnt get the RCD's to hold due to IR faults or perhaps borrowed neutrals or even an incorrectly wired CU and decided the best and safest option was to just get rid of the pesky RCD's. Incredible.
A slightly more clued up cowboy would at least have had the sense to identify the IR failed circuits and put just those on the main switch side or stick circuits with shared neutrals on the same MCB/RCD.
Believe or not I used to work for a guy who used to swap out RCD's for main switches because he didnt know how to make high integ boards work. He was fully apprenticed 2360 level 3, NVQ 3 AM2 and Elecsa registered.
That was around the time I decided I should probably work for myself.

eh?....lol

 

[KingKenny]

Just as a matter of interest, where about in the UK is this installation?

It's in Northern Scotland, richy - most of the houses around here are old croft / farming properties - new builds are slowing down at present.

Thanks to everyone for their kind advice, and I hope those of you who have gone off on a tangent find your way back safely soon.

As the OP, I did post a follow up question about galvanised steel bein embedded in the outer structure of the property, between the pored concrete outer and cladding inner. Has anyone come across this before?

Ta. Kk

 

[richy3333]

It's in Northern Scotland, richy - most of the houses around here are old croft / farming properties - new builds are slowing down at present.

Thanks to everyone for their kind advice, and I hope those of you who have gone off on a tangent find your way back safely soon.

As the OP, I did post a follow up question about galvanised steel bein embedded in the outer structure of the property, between the pored concrete outer and cladding inner. Has anyone come across this before?

Ta. Kk

Had a feeling that was the case from the setup in the picture and the description of the property. How 'north' is north? East or West? I've had to contend with a few similar properties. I presume this isn't a crofters house - they wouldn't willingly pay for smoke detectors and crofting properties are rarely of concrete construction. Somebody mentioned earlier that the smokes were on the heating board, is it a THTC board?

 

[Outspoken]

this is twaddle....
yet again we have someone in here who has clearly shown they havn`t a sweet doodle what their talking about.....
getting a bit regular is this.....

Have you read the subsequent posts or just climbed on your soapbox again?

Now as I said in a previous post, I do not do domestic toy boy installations, I do real electrical work so if your happy that a given installation is perfectly safe after a test then that's fine, no need to rewire, cables these days are better quality than years ago, but as various home insulation materials over the years have been known to have detrimental effects on cables that are covered or buried in them, this much be taken into consideration when deciding if a given installation may require a partial or total rewire. Clearly this will depend on the level of scrutiny your able to give it under a visual inspection.

 

[KingKenny]

Had a feeling that was the case from the setup in the picture and the description of the property. How 'north' is north? East or West? I've had to contend with a few similar properties. I presume this isn't a crofters house - they wouldn't willingly pay for smoke detectors and crofting properties are rarely of concrete construction. Somebody mentioned earlier that the smokes were on the heating board, is it a THTC board?

Ha Ha! - It's on the Western Isles, mate. It's not a crofter's house as such, just built in that 'style' in one of the small townships that abound. The man of the house passed away quite a while ago and I think his wife ordered or was persuaded to upgrade the smoke detection and heating. It all seems reasonably sound, but I'll find out more next week. The smoke detectors are on the same circuiyt as water boost and a couple of other things (can't recall of the top of my head), but aren't on the same circuit as storage heating. The ring, radial and lighting are in a mess though. It isn't the lil (little old lady) ordering the work though, it's her son I've been dealing with. Fairly sharp bloke, except when it comes to wiring a plug.

 

[oldtimer]

Have you read the subsequent posts or just climbed on your soapbox again?

Now as I said in a previous post, I do not do domestic toy boy installations, I do real electrical work so if your happy that a given installation is perfectly safe after a test then that's fine, no need to rewire, cables these days are better quality than years ago, but as various home insulation materials over the years have been known to have detrimental effects on cables that are covered or buried in them, this much be taken into consideration when deciding if a given installation may require a partial or total rewire. Clearly this will depend on the level of scrutiny your able to give it under a visual inspection.

You talk about soapbox but your handle outspoken infers the same is the any chance you could give your ego a rest as in my view all you seem to be doing is having a pop for the sake of it .

O and by the way before you try and slag me off I have an Industrial & Commercial background been lucky to work across most electrical fields and I am happy to help always learning don't have an ego to bruise and actually state where I come from because I aint that insecure

 

[Outspoken]

You talk about soapbox but your handle outspoken infers the same is the any chance you could give your ego a rest as in my view all you seem to be doing is having a pop for the sake of it .

O and by the way before you try and slag me off I have an Industrial & Commercial background been lucky to work across most electrical fields and I am happy to help always learning don't have an ego to bruise and actually state where I come from because I aint that insecure

OT, no ego here and only speaking out when people are clearly not reading the entire thread or an entire post then having a pop at me...if they can read they should and perhaps they would then avoid making posts that provoke the response I gave.

Incidentally I do not see that your background in Industrial or Commercial makes a lot of difference, anymore than mine does or someone who specialises in domestic, we are all qualified sparks, we just have different experiences and can all read a regs book if we can be arsed.

 

[richy3333]

Ha Ha! - It's on the Western Isles, mate. It's not a crofter's house as such, just built in that 'style' in one of the small townships that abound. The man of the house passed away quite a while ago and I think his wife ordered or was persuaded to upgrade the smoke detection and heating. It all seems reasonably sound, but I'll find out more next week. The smoke detectors are on the same circuiyt as water boost and a couple of other things (can't recall of the top of my head), but aren't on the same circuit as storage heating. The ring, radial and lighting are in a mess though. It isn't the lil (little old lady) ordering the work though, it's her son I've been dealing with. Fairly sharp bloke, except when it comes to wiring a plug.

Aah, OK. Sorry to quiz but I was worried that you were one of the unregistered spark around my way that keeps leaving dangerous installations in their wake!
The pics not great, but the board does look like a THTC setup, if so they have potentially taken the smokes off the perm live feed, which isn't allowed under Hyrdo/SSE rules. If things are that messy, it sounds like a rewire is the order of the day. Good job for you

 

[dave1064]

I would definitely suggest a rewire. If you are saying these sockets are wired as a radial then the protectice device cannot be rated at more than 20A.

If the sockets and lights are missing earths this must be sorted to meet the standards of current regulations. BS7671. If it is a conduit system then the conduit could be used as a means of earthing. That way a seperate c.p.c is not required.

My advice would be to rewire the radial circuits and create a ring circuit instead. Definitely check out the JBs as you often find all kinds of things in there!

Hope you find this helpful.

 

[Outspoken]

If it is a conduit system then the conduit could be used as a means of earthing. That way a seperate c.p.c is not required.

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.

 

[dave1064]

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.

Hence why we carry out inspection and testing. I was only meaning the conduit could have been used as a means of Earth. I would prefer to run a seperate c.p.c in any circuits I install.

Conduit installed properly to satisfy the regs and protected against external influences is satisfactory to be used as a means of Earthing.

 

[Outspoken]

 

[KingKenny]

Aah, OK. Sorry to quiz but I was worried that you were one of the unregistered spark around my way that keeps leaving dangerous installations in their wake!
The pics not great, but the board does look like a THTC setup, if so they have potentially taken the smokes off the perm live feed, which isn't allowed under Hyrdo/SSE rules. If things are that messy, it sounds like a rewire is the order of the day. Good job for you

No, richy - I don't and won't leave dangerous installations around anywhere. I've not done many big jobs as yet, but I'd like to think I'm meticulous in how I go about things - at the very least I would never ever leave a premises knowing full well I've left anyone in danger - even if that means calling in someone more experienced than me and me losing the payday.

 

[KingKenny]

I would definitely suggest a rewire. If you are saying these sockets are wired as a radial then the protectice device cannot be rated at more than 20A.

If the sockets and lights are missing earths this must be sorted to meet the standards of current regulations. BS7671. If it is a conduit system then the conduit could be used as a means of earthing. That way a seperate c.p.c is not required.

My advice would be to rewire the radial circuits and create a ring circuit instead. Definitely check out the JBs as you often find all kinds of things in there!

Hope you find this helpful.

Thank You, Dave. My intention is to totally replace D/L Lighting, U/L Lighting, Upstairs Ring (lounge, Bedroom, Hall), downstairs ring (Bedroom, Kitchen, downstairs hall), Cooker, (new) Shower on separate radials. Main Bonding needs to be upgraded too - the existing cable is painted, plastered into the wall in the bathroom. C/U unit will (obviously) be replaced. My only question is whether I have the small Kitchen d/w and washing machine on the same ring as the bedroom and kitchen sockets (6 doubles in total - which COULD mean, at worst, microwave, kettle, d/w w/m and a telly in the bedroom being on at the same time) or to put the w/m and d/w on a separate one... I'll look at the diversity calcs and have a good think about this - there will certainly be plenty of space on the board for me to split them out if I want/need to.

 

[dave1064]

Not a problem.

I could suggest that you could wire a seperate kitchen ring from the house ring. The largest load demanded in a house is from the kitchen due to these appliances. Where the rest of your house typically consists of a television and appliances like that.

 

[KingKenny]

Not a problem.

I could suggest that you could wire a seperate kitchen ring from the house ring. The largest load demanded in a house is from the kitchen due to these appliances. Where the rest of your house typically consists of a television and appliances like that.

Yep, was thinking this, but 'the rest of the house' downstairs is just 3 more sockets in a bedroom, so was wondering if these could just 'extend' the kitchen ring as they are not much extra load - if any as bedtime and cooking time are different!!. I did want to separate the upstairs and downstairs rings in case of failure on one of these circuits, though. Are you still working in Scotland now?

 

[dave1064]

Yes I work in Scotland.

A downstairs and upstairs ring should be suitable in that case.

Was going to ask if you were changing the consumers unit but I noticed in your previous post you said you were.

 

[richy3333]

I would definitely suggest a rewire. If you are saying these sockets are wired as a radial then the protectice device cannot be rated at more than 20A.

If the sockets and lights are missing earths this must be sorted to meet the standards of current regulations. BS7671. If it is a conduit system then the conduit could be used as a means of earthing. That way a seperate c.p.c is not required.

My advice would be to rewire the radial circuits and create a ring circuit instead. Definitely check out the JBs as you often find all kinds of things in there!

Hope you find this helpful.

Why does he have to create RFC's? What's wrong with radials?

 

[dave1064]

Rings are capable of carrying a much higher current. Would you put all your kitchen appliances on a single 2.5mm cable?

Unless of course you can find some 4mm cable