Fault, state of install and possible CU replacement

[leezer3]

OK, so apologies in advance for what's going to be a long-ish post.
FWIW I'm a reasonably competant DIY-er, but I don't have any decent test gear, just a standard meter

Things started on Thursday afternoon, when the RCD tripped out. After a lot of chasing, it was determined that the lights circuit has a fault. I checked for water in the two outside lights, loose connections and obvious damage & then reached the limit of what I can really do & called the electrician.

He was only able to do two hours this morning, but the fault has been isolated to the string of three lights after the kitchen, ending in the outside lights. (Proabable culprit I suspect)

In the course of this fault finding, we've basically discovered that the electrics are extremely untidy to say the least. Nothing majorly dangerous (AFAIK), but a mess. The house has also always been short on sockets.
I queried whether it would be possible to switch the lights onto a RCBO, and his opinion was that going that route, it'd be better to do a a swap for a full RCBO board, which is something I'd consider.

The current CU is a Volex Protector, ~20 years old. Main bonding is in place to both gas & water. Circuits look like this (L-R):
32A cooker (4mm2 I think)
32A shower (4mm2)
16A radial, downstairs sockets x5
16A radial, upstairs sockets x4 & model railway loft socket through 3A FCU
16A 'lollipop' (4mm2 to kitchen, then 2.5mm2 ring) kitchen sockets x6 & boiler
16A unlabelled, I *think* this does the socket behind the fridge, although I'm by no means certain.
10A lights (1.5mm2 cable)

I know there are junction boxes *everywhere*; we found three under the landing in the process of looking for the initial fault, and I'm aware of two more in the loft and one under the floor. (Socket circuits all seem to be wired to a JB then to the sockets in a star pattern. Lights all appear to have 1 JB per fitting from a central JB)

He was of the opinion that the junction boxes and general mess of wiring wouldn't make any difference to changing to an RCBO board, and that once this issue is fixed, it'd only take 2-3 hours to swap and test the remaining circuits, at which point he could add another 4 socket radial downstairs in about an hour.


Does this sound relatively reasonable?
The junction boxes everywhere syndrome does concern me a little, as does the kitchen lollipop.

 

[EFLImpudence]

I would say the primary answer is "It's up to you".

RCBOs are the 'best' we have at the moment but are relatively expensive.

You have had (still have) one fault which has taken out all the power which is inconvenient and could be dangerous at night.
How long has it been since the last?

To add a four socket radial in an hour is good going.
The only answer to the junction box problem is rewiring.
I don't think you have used the term 'lollipop' correctly.

You have an electrician who, I'm sure, will be happy to advise you.

 

[leezer3]

Very true
We're concentrating on getting the fault fixed at the moment (The 'string' has been disconnected, so most of the lights work & it's not dangerous per-se), and I'm trying to better understand the options available to me to improve the current situation

This fault is probably the third in six years, not counting a pinched wire I caused when changing a socket, so the system is by no means trip happy.
The primary thing I'd like to do is to separate things so *if* it does decide to trip again I don't loose all light. It took me the better part of half an hour to figure out what was going on, and was basically a PITA.
Whilst a 17th split load board would do this, I suspect the £50 odd extra outlay for all RCBOs would end up being better in the long run.


Saying that, I honestly don't know the best way to go forwards- He doesn't appear to see the junction boxes as an issue, and he wasn't altogether convinced either of the need to change the CU at all.
I can't say I'm convinced either, but this is where I need a second opinion on what he's saying and the feasibility of the options in question

(By lollipop, I mean a 4mm2 single cable runs from the CU to underneath the kitchen cupboards. This then hits a JB, from which the sockets are run in a ring around the worktops)

 

[EFLImpudence]

(By lollipop, I mean a 4mm2 single cable runs from the CU to underneath the kitchen cupboards. This then hits a JB, from which the sockets are run in a ring around the worktops)

That is correct.

I thought you were referring to the 'star pattern' as you hadn't mentioned a 'lollipop'.

 

[mfarrow]

The best way to determine whether you need a re-wire or not would be to have an EICR (Electrical Installation Condition Report) conducted, which would do all the tests you can't and flag up any problems with other circuits, and also determine the suitability of the existing wiring to accept a new board.

The junction boxes are a departure from current regs, however they have been installed under floorboards of many homes in the past, and continue to be in use without issue. If you have specific concern still, I suggest replacing them with maintenance-free junction boxes unless the EICR forces a re-wire anyway.

 

[leezer3]

So, the fault was eventually found (4 hours labour) as a cable trapped between a floorboard and the joist in the upstairs bathroom. Lovely burn on it, and I'm amazed it hadn't tripped things before, as I certainly haven't touched the floor in the last 6 years.

I'm waiting for the bill and certificate for this, but he was of the opinion that the wiring itself was in generally good if untidy condition for it's age, and a rewire was unnecessary for the minute (Although that's obviously with only minimal visual inspection of the other circuits)

Don't know where I'm going just yet, I need the bill and a further discussion on costs vs. absolute benifits before I do much more