Straight consumer unit switch or not?

[eBatch]

House completely rewired c.1990 (under auspices of IEE 15th).

However, consumer unit was not replaced and still old re-wireable fuses (which are very reliable and have never been an issue).

If want to have new consumer unit installed now, would it be just a straight switch-over job between old and new consumer unit?

Or do later / current regs mean that more extensive work now required? Is so, what sort of other work?

 

[bernardgreen]

Or do later / current regs mean that more extensive work now required? Is so, what sort of other work?

That can only be answered after an inspection on the wiring and a series of tests on said wiring.

and still old re-wireable fuses (which are very reliable and have never been an issue).

A fuse is only "reliable" if it blows when there is an overload on the circuit it is protecting.

 

[PrenticeBoyofDerry]

If want to have new consumer unit installed now, would it be just a straight switch-over job between old and new consumer unit?

Not straight forward swap or you could have power-loss issues.
It is recommended that you have your existing installation inspected and tested via an electrical installation condition report (EICR).

This will flag up an issues and upgrades that are needed to be addressed and that your installation is suitable for a consumer unit with RCD protection.

If the house was correctly wired in 1990, there maybe some minor upgrades, but overall I would expect a good outcome.

 

[ban-all-sheds]

There's no generic reason why a 1990 installation should need any work doing on it in order to swap the CU.

BUT a lot can have happened to it in 25 years, so your specific installation might need things done - circuits/cables might be damaged, additions using the wrong cable or topology may have been added and so on.

Two things to consider:

A significant introduction into yours will be RCD protection, and that can uncover faults, or faulty appliances, of which you were unaware.

You might want to take the opportunity to split circuits up and/or add new ones, for example if you have one lighting circuit, changing it to two - upstairs and downstairs, and that might mean a bit of modifying how the landing light is wired.

Do not go with anybody who plans to just replace the CU and fix any problems encountered as he goes - what you want is the existing installation checked out first so that you're aware of any problems which need fixing beforehand.

An all-RCBO CU is better than one with a couple of RCDs, and probably not a lot more expensive.

As ever, personal recommendations are always the best way to find a reputable tradesman, but if you're having to go ahead without much in the way of those, or references, don't put any store by registration itself - sadly it is possible to become registered with woefully inadequate qualifications and zero practical experience. You don't have to spend long here to see people cropping up who are registered and "qualified", but who are clearly seriously incompetent in reality and who should not be charging for their services.

It's your money, £'00s of it, and you have every right to ask prospective tradesmen what their qualifications are. Just being listed here is not a good enough guide. No genuinely experienced electrician, with the "full set" of C&G qualifications will mind you asking - in fact he will wish that everyone was like you.

I feel sorry for people who have been misled by training organisations and (shamefully) the Competent Person scheme organisers into thinking that a 5-day training course, a couple of trivial examples of their work and some basic understanding of how to use test equipment will make them an electrician, but not sorry enough to agree with them trying to sell their services to Joe Public.

 

[ban-all-sheds]

Just a thought - given the stories we read of troubles with intermittent RCD trips, either because of intermittently faulty appliances, or random totting up of multiple power supply leakages, does the team think that there is a case, in situations like this, for the temporary installation of an RCD before the CU, to be left for a while to see if anything is picked up?

 

[Iggifer]

I am of at somewhat of a loss as to understanding why the board wasn't changed with the rewire.

I've not been around long enough to know when the regs required RCDs, I'm presuming 16th?

 

[PrenticeBoyofDerry]

I've not been around long enough to know when the regs required RCDs, I'm presuming 16th?

Well that would depend on the installation type/earthing arrangement.

But if we ignore TTs, really RCDs are quite a new thing for compliance.

 

[PrenticeBoyofDerry]

Just a thought - given the stories we read of troubles with intermittent RCD trips, either because of intermittently faulty appliances, or random totting up of multiple power supply leakages, does the team think that there is a case, in situations like this, for the temporary installation of an RCD before the CU, to be left for a while to see if anything is picked up?

Providing the customer is happy to potentially have complete power loss!

 

[RF Lighting]

I am of at somewhat of a loss as to understanding why the board wasn't changed with the rewire.

I've not been around long enough to know when the regs required RCDs, I'm presuming 16th?

We were still fitting wylex rewireable fuse boxes when I was an apprentice in about 1996

Under the 16th edition it was only a requirement to RCD protect sockets likely to supply equipment for use outdoors, although it was common practice to protect all sockets.

 

[plugwash]

Just a thought - given the stories we read of troubles with intermittent RCD trips, either because of intermittently faulty appliances, or random totting up of multiple power supply leakages, does the team think that there is a case, in situations like this, for the temporary installation of an RCD before the CU, to be left for a while to see if anything is picked up?

To what end? all it will tell you is that there are either no problems or that there is a problem is some unknown place, not especially useful.

Better to fit the CU full of RCBOs, then if one does trip at least you have some idea where the prolem is.

 

[Adam_151]

We were still fitting wylex rewireable fuse boxes when I was an apprentice in about 1996

Really?

I presumbed that anyone still fitting the wyke standard range in the 1990s was at least fitting the cartridge fuse carriers.

Took out a rewireable board fitted in 85 and remember thinking thats a bit late for re-wireable board

 

[RF Lighting]

We generally used them for storage heating installations and the like, and them new fangled split load boards for standard domestic installs.

It may have partly been due to working for an old boy who still liked to do things the proper if slightly old fashioned way.

 

[sparkwright]

Like RF, I was still fitting those traditional Wylex boards in the mid 1990s for various applications.

It is quite likely that board you describe was new in 1990 - though if you say it wasn't then we won't disagree.

Everyone used those Wylex throughout the 60s, 70s and 80s.

 

[ban-all-sheds]

Providing the customer is happy to potentially have complete power loss!

Well - the electrician could hang around for a cuppa while he packs up, and that would show if there were any gross problems, maybe get the oven fired up too. And be ready for a prompt return to bypass/remove it if it does trip often. Or have it in an enclosure with a changeover switch so it can easily be bypassed.

It's probably not worth it if an all RCBO CU is going in.

 

[ban-all-sheds]

To what end? all it will tell you is that there are either no problems or that there is a problem is some unknown place, not especially useful.

I think it could be useful to know that there's a problem before it becomes one which is a PITA to deal with. i.e. when the RCD is external and temporary, not after the new CU has been installed.