kitchen ring circuit

[flinskint]

Hi there,
I have recently taken up the old carpets all round the house and thought it a good time to investigate the wiring.
A bit of background, apologies if its long winded or too vague, but I may have a few questions, so here goes:

I have an old 6 way wylex CU with two 5amp up/downstairs lighting circuits, two 30amp one for cooker radial and one for ring main.A 15amp I assume is for the boiler and another 5amp which supplies my alarm via an fcu.
I haven\\\'t had any problems with the existing set up since i moved in, i am just trying to get a better idea of what is going on really.

I understand it is best to have a separate ring for each floor but I have a concrete ground floor in the back room and kitchen extension.
The ring drops down to feed a few sockets in the lounge then goes back up through the back bedroom floor and into the kitchen/extension.(socket in back room is a spur from landing)

In the kitchen the cable appears to drop down and back up from the roofspace through a switched FCU and then on to ring linked sockets around the kitchen, eventually going back through to the bedroom.
The switch on the FCU does not seem to cut power to anything when switched off? could it be wired to bypass the switch?

House is a small/medium terrace, is it likely that the 50m/60m cable length rule will be a worry,with just the one ring?

thanks in advance

 

[Steve]

there are no cable length rules with ring mains, just the floor area. Are you sure the 15A fuse isn't for an immersion heater? strange for an old install to have a seperate fuse for a boiler. Old Wylex fuse boxes are on their way out these days, always a good idea to replace them.

If you really want to get a good idea of whats going on, invest in a PIR - periodic inspection report - this will tell you what needs doing to the installation - if anything. Any good spark will do one for you.

Being honest, it may be time for a rewire - to have only one ring main is near-on criminal these days - not enough capacity for a modern house. Rooms with concrete floors can be dealt with by running a radial circuit, as opposed to a ring final.

Open up that switched FCU - I hope all the cables are connected to the supply side.

 

[flinskint]

Firstly cheers crafty for your response.
I am uncertain of what the 15amp circuit is for but it looks like it feeds the combi boiler via an fcu, although the boiler still fires up when the breaker is removed, don't know if it needs the supply for that?

I shall start saving for a new CU then, though I reckon the wiring is in pretty good nick,would just maybe need the ring splitting in two.
Would replacing the Fuses with push button mcbs offer any improved safety in the mean time?(my bro has some spare he'll give me)

A PIR sounds spot on really, but as my username suggests, funds are tight. Could I get an old sparky friend of mine to do it ?(think he does mainly industrial work but definately knows his stuff)
If not, how much roughly should a PIR cost?
I was going to to ask him to replace the CU, is this a job that will need certificates/paperwork?

The switched FCU is wired in and out of the (top) supply terminals.
As this is fused it ok for me to ask for say two double sockets to be wired from the (bottom) outlet side?

Sorry for so many questions!
Your time and wisdom is much appreciated
Cheers

 

[ban-all-sheds]

Firstly cheers crafty for your response.
I am uncertain of what the 15amp circuit is for but it looks like it feeds the combi boiler via an fcu, although the boiler still fires up when the breaker is removed, don't know if it needs the supply for that?

Yes it does - turn off the FCU, or remove the fuse if it's an unswitched one, and you'll find out.

Combi boiler post-dates the electrics, so it's very likely that the 15A circuit was for an immersion heater. The boiler spur is probably from the socket circuit.

I shall start saving for a new CU then, though I reckon the wiring is in pretty good nick,would just maybe need the ring splitting in two.

Or maybe more changes than that - the items on the list below may not all apply to you, but they are worth looking at to get you thinking:

1. Upstairs sockets
2. Downstairs sockets
3. Kitchen sockets
4. Circuit for appliances
5. Cooker circuit
6. Non-RCD circuit for F/F
7. Non-RCD circuit for CH boiler
8. Dedicated circuit for hifi
9. Dedicated circuit for IT equipment
10. Upstairs lights
11. Downstairs lights
12. Immersion heater
13. Shower
14. Alarm
15. Supply for outside lights
16. Supply for garden electrics
17. Supply for shed/garage

Plus any peculiarities brought about by your house layout & construction - e.g. in mine because of solid floors and where the rest of the sockets are, I have a radial just for one socket in the hall, the doorbell and the porch lights.

Plus a few spares on RCD & non-RCD sides for expansion beyond that for future unforeseen needs.

Would replacing the Fuses with push button mcbs offer any improved safety in the mean time?(my bro has some spare he'll give me)

Not really, if the wiring is in good condition. See what test results the PIR throws up, and discuss it with your sparky.

A PIR sounds spot on really, but as my username suggests, funds are tight. Could I get an old sparky friend of mine to do it ?(think he does mainly industrial work but definately knows his stuff)

He should be able to do it.

If not, how much roughly should a PIR cost?

Low hundreds.

I was going to to ask him to replace the CU, is this a job that will need certificates/paperwork?

Yes. If he's a qualified electrician, then he is perfectly capable of issuing the electrical certificates required.

However, replacing a CU is notifiable in terms of the Building Regulations, and if he's not registered with one of the Competent Person schemes then he won't be able to certify compliance with the Building Regulations. But talk to your LABC - if he's qualified, it is very likely that they will be perfectly happy with his ability to do the electrics, and they'll provide the Building Regulations Completion Certificate. You will have to pay them their fee, though, for them to do basically SFA, but so it goes.

The switched FCU is wired in and out of the (top) supply terminals.

That may be a mistake, or it may be that whatever the FCU used to supply is no longer there. Strongly suggest that you get your friend to pay particular attention to that, and make sure that some bozo hasn't wired it incorrectly..

As this is fused it ok for me to ask for say two double sockets to be wired from the (bottom) outlet side?

Yes, but if changes are afoot, you might like to bite the bullet now and have proper circuits installed.

Sorry for so many questions!

Better to ask too many questions than too few...