Confirmation required please

[nettie2006]

I still haven't installed my kitchen yet as the electrics needed a bit of investigation.

With my next door neighbours help (he's taller and more knowledgable) I found out that my house appears to have
Two radial ccts: one for the upstairs sockets and kitchen & one for the downstairs each wired in 2.5mm2 (I thought it was a ring main with some extra uncompliant spurs)
These are both wired into the same 30A MCB

As the Consumer unit is only rated at 63A and has
1 30A MCB for the sockets
1 30A MCB for the Cooker
1 5A lighting MCB for the lights
1 5A lighting MCB for the upstairs landing light only!

I am supposing this was a bodge job to avoid 2 20A MCBs which would break the rating of the consumer unit. visuallly more compliant but functionally more dangerous.

If I separate the two radial sockets ccts and power each via their own 20A MCB, would this be acceptable?
I could put the downstairs sockets on a lower Amperage MCB if they are available if the consumer unit needs it.

I plan on putting a note in the Consumer unit to advise that any further work required neccesitates the house being introduce to the joys of ring mains! Up with the carpets and floor boards


The P regs won't stop the bad but qualified guys unfortunately

 

[il78]

How did you determine that the sockets are on radial and not a break in the ring...

 

[nettie2006]

Only two wires into the MCB from two cables.
Removing one switches off the kitchen and upstairs sockets.

The other cable runs down the wall and powers the donstairs apart from the kitchen.

Kitchen is definitely radial with visible end in one wall socket

No socket yet found with ring power only single feed.

Could be the guy planned a ring and fogot to install the last cable at the kitchen sockets (which power the washing machine)

 

[Spark123]

I think it is probably worth your while getting a PIR carried out to check the state of the installation as there may be other underlying problems.

 

[nettie2006]

Other underlying problems, such as?

I've been going from socket to socket checking the wiring and mapping the cable route/connections and checking the earthing.

 

[Spark123]

Generally as a DIYer you will not have access to the required instruments required to carry out a full check of the installation i.e. if the cables have been used above their current carrying capacity the insulation may have been damaged. Unless you have access to an insulation resistance tester this damage can go undetected. How do you mean checking the earthing?

 

[nettie2006]

Continuity, resistance back to the Consumer unit.
Yes, I do have access to a PAT tester.

Next door neighbour does electrical work for the council and has all the toys I don't have. I used to use a PAT tester for indiviual pieces of equipment years ago when no paperwork or courses were required.

 

[Spark123]

PAT tester = Portable appliance tester i.e. used for testing portable appliances, not fixed installation wiring.
If your neighbour can do a full PIR for you then this is better, this should tell you what work is required to bring the installation up to the requirements of BS7671:2002 am2 2004.

 

[nettie2006]

PAT tester was an example.

But, I still need an answer to the original question as I think the installation, as is, is flawed. The potential damage which may have already been caused is a secondary item.

As I have not yet seen any house of mine's installation without faults I'm not convinced about the quality of anyone's work irrespective of their qualifications. (I'm a long term electronic and electrical engineer, up to speed on the theory but not the practical application of home electrical installations)

 

[Spark123]

re using 2x20A MCBs this will give the circuits better protection, although I'd consider the downstairs one may be prone to tripping when high current using appliances such as a washing machine, tumble dryer, kettle are used simultaneously. Socket outlets which can be reasonably expected supply equipment outdoors should also be RCD protected.

 

[nettie2006]

They'll have no chance of tripping the downstairs circuit

They're on the upstairs circuit. The kitchen only has room for a fridge freezer and washing machine.

There is b****r all on the upstairs sockets. My laptop and the network port. Not big on atmospheric bedroom lighting!

I appreciate the help here. I will be getting the system checked but I find one is far less likely to get the wool pulled over one's eyes if one can keep up.

I know far more than I need regarding cars (and more than I want) now but don't pay over the odds being scammed.

Re the consumer unit being rated at 63A. Is it a problem having a

5A +5A +20A +20A +30A MCBs?

Currently 5A (neglible load), 5A, 30A, 30A.