Cowboy wiring - grumble, grumble, grumble.

[Martin]

Hi All,

I think cowboys have previously been at the wiring of my house - if I briefly explain the setup would anyone care to pass comment on how bad my mood should be? Also what sort of investigation and subsequent work would you think appropriate.

I'm looking into this as I'm planning a new kitchen ASAP. I appreciate I may have to call in the professionals(??) but I would like to understand what is going on first.

The house has a new consumer unit which has to be good thing and I have no problems with breakers tripping etc. Here is what each breaker seems to control....

1) Labelled: Shower Rating: 16 amp 1 thin wire going in. Controls: garage -one dbl socket, extractor fan, light in downstairs loo (spurs off of spurs etc) landing - one dbl socket study - two dbl sockets spare - one dbl socket bedroom - three dbl sockets

2) Labelled: Sockets Rating: 32 amp

2 thin wires Controls: living room - 3 dbl sockets kitchen - 2 dbl sockets

3) Labelled: Sockets Rating: 40 amps

1 thick wire Controls: Kitchen cooker socket (hob and oven are both gas - control igniters only) Shower

4) Labelled: lights Rating: 6 amps

1 thin wire Controls: Upstairs lights

5) Labelled: lights Rating: 6 amps

1 thin wire Controls: Downstairs lights

Many thanks,

Martin.

[Lurch]

That looks like a radial circuit. There should be a fused spur somewhere with a 3\5A fuse controlling the ex fan and wc light.

Looks right.

Looks like this is totally wrong. There should be a seperate circuit for cooker and shower, mast probably 32A each.

Seems fine.

Seems fine. I think it needs some attention, the labelling is an annoyance if nothing else. The circuit controlling the cooker and shower is totally wrong and should be corrected *immediately*. ..

SJW A.C.S. Ltd.

[John Rumm]

Additional question - is there a shower fitted? If so what is it rated at (i.e. how many kW)?

[Dave Liquorice]

For a start labelling is all to c*ck, easy enough to sort out...

This is rather odd. All those sockets should be on a 32A ring. Though a 16A radial is within the regs I think provided the cable is 2.5mm^2. I take it you don't actually have an electrically heated shower. I wonder if someone has broken the ring fitting those spurs. Time to trace the wiring if you can. The spurs off spurs is suspicious and needs to be corrected anyway.

Seems OK. Downstairs ring main.

Wrong label. Should be "Cooker". Position 3 may be dubious, it is recomended that heavy loads like cookers and showers are placed in the CU as near to the main switch as possible.

Seems OK, label could be better "Upstairs Lights".

Seems OK, label could be better "Downtairs Lights".

[Lobster]

Surely this isn't *that* bad, given that the OP has all-electric cooking? Agreed it's wrongly done, given that it would be possible for him to go out and buy an electric oven and plug it in to the same circuit as the shower; however given that constraint, it doesn't look like an urgent problem. (And does he actually have an electric shower?!)

Presumably at some time in the past, when the shower was fitted, the fitter would have found the 40A circuit with no oven on the end, and decided to hook the shower up to that rather than install a new circuit?

David

[Dave Liquorice]

And shower? Reads OPs post again, ah piss poor formating "hid" the word shower. My previous post in respect of this section is wrong.

The OP has all gas cooking and from that perpesctive it's "safe" but definately not good practice or in line with the regulations.

As the OP said a cowboy. The shower must have it's own circuit and the electric cooker point another. Is there a spare way in the existing CU to add another MCB. I suspect not as changing the CU would have put up the cost of the shower installation and the sharing of cooker/shower MCB a cheap bodge work around.

[Martin]

Hi All,

A wealth of good advice as always!!

Just checked the shower and it is rated at 9.5KW so a 40amp breaker I understand to be adequate.

Howzabout if do the following when I fit my kitchen?

1) Label it correctly!! 2) Remove the cooker socket from the 40 amp breaker and check it! 3) Sort out the WC light, fan and garage onto a fused connection(s). 4) Try to trace what is going on with the 16amp (presumed radial) wiring and sort out if required. 4) Add the additional sockets required for the kitchen to the downstairs ring as there isn't much on it at the moment. This would include a new (13amp rated) electric fan oven. I've put in a ring main for a kitchen in the past so the mechanics of it I'm fairly comfortable with. I was tempted to put a seperate ring in for the kitchen this time but the CU is approx 40 feet away and routing the cable would involve chasing out walls (again!) and lifting the floor in three seperate room and a landing. In this case as there are only 5 dbl sockets on the downstairs ring so would this be OK?

Incidentally, how would I earth bond the new stainless sink and associated pipework? Incoming water main is plastic.

Many thanks,

Martin.

[chris French]

A bit, but nothing that wrong with it.

They might be better, but not a case of 'should' really. Assuming they come within the floor area recommendations (20 Sqm?)

They don't look as if they are serving areas where they are likely to be presenting a large load - assuming nothing like an 3 kW electric fan heater is going to be often used. My upstairs ring (as it is now) spent about 18m months as a radial pending completion of the circuit. The biggest load they regularly get is the vacuum cleaner I should think.

Though as someone else pointed out the fan and light should be on a fused spur.

It could be probably be uprated to 20A.

Why? it's a radial circuit - it is effectively all spurs.

My only concern here is what size are we talking about with these 'thin' wires - the op has referred to thin wires as being used in the lights the rings and the radial.

[Dave Liquorice]

I used "should" not "must"... If only because people expect sockets to be on a 32A ring these days and thus expect to be able to load that ring up to 7+kW... And if it is 20sqM then thats just about a single room or do you mean a space 20m x 20m = 400m^2?

The OP might not but future owners?

That bothered me a little bit as well.

[Martin]

Hi,

Sorry but I should of been more specific about the cables used.

Thin wire - looks like 2.5mm Thick wire - looks errr....thicker. 4mm?? 6mm??

Perhaps my slightly revised plan of action should be ...

1) Label it correctly!! 2) Remove the cooker socket from the 40 amp breaker and check it! 3) Sort out the WC light, fan and garage onto a fused connection(s). I want to put a fused connection in the garage anyway for other reasons. 4) Look into converting 16amp (presumed radial) wiring into a proper circuit. 5) Add the additional sockets required for the kitchen to the downstairs ring as there isn't much on it at the moment. This would include a fused connection for an electric fan oven.

What do you reckon?

[Dave Liquorice]

Yep.

Well as another bodge yes but the position of the outlet will mean that it may well get used for a "full power" cooker at some future date. It really ought to have it's own feed from the CU in suitable cable and rated MCB. So should the shower.

Be better if the garage sockets where RCD protected. Most likely place to be using power tools or taking a fed out into the garden. Note: that RCDs need thinking about if you have more than one, they should not be connected in series without thinking.

Personally I'd go for a separate ring for the kitchen, it's where most heavy domestic loads and 7kW is fairly easy to acheive. 3kW (fast heat) kettle, washing machine heating water 2kW, tumble dryer drying previous load 2kW or toaster or microwave or... doesn't leave you much room for everything else downstairs.

[Christian McArdle]

You don't need supplementary bonding. Supplementary bonding in a kitchen may reduce safety under certain conditions.

The pipework in the house should be main bonded on entry to the building, but only if it is metal. This requires a thick unbroken cable from the entry point to the main earthing terminal.

Christian.

[Martin Angove]

Found a similar situation at a house recently. There was a 4-way CU (lights/immersion/sockets/32A shower) and the new owner found the oven and 6.7kW hob plugged into an extension lead. The shower MCB had previously been supplying a cooker point but, although I found the cable as it ran under the floorboards, it disappeared into a newly-tiled wall so instead of a simple reconnection job (was fitting a larger CU anyway) I had to run a completely new circuit for the hob and oven :-(

I think this was a DIY-er cowboy rather than a pro though.

Hwyl!

M.

[Martin Angove]

A radial in 2.5mm2 protected by a 20A breaker can serve up to 50m2 (50 square meters, i.e. about half the floor area of a four bed semi) with as many sockets as you like, and whatever topology ("spurs on spurs") takes your fancy. See the On Site Guide table 8A (p151).

If you want a 32A circuit it either has to be a radial as above, but wired in 4mm2 cable, or a ring circuit wired in 2.5mm2. A 32A/4mm2 radial can serve 75sqm, a 32A/2.5mm2 ring 100sqm.

HTH

Hwyl!

M.

[Toby]

How is life as a pro?

[Martin Angove]

So-so. The electrics I can handle, it's the "making good" I have trouble with :-)

Not done any advertising so far (though I have a little planned) but people keep ringing me up and asking me to do work.

As others advised when I first said I was thinking of this, it is darned hard work, and my first few estimates were wildly inaccurate, but I'm getting the hang of it now. I might even be in a "positive cash flow" situation soon.

I've come up with an interesting angle though which I might persue - it avoids a lot of the hassle jobs: advertise as a service for DIY-ers. I would "consult" - doing design and calculations, checking and advising if required and testing afterwards. I wonder if this would work?

Thanks for remembering...

...and if anyone needs my services, I'm in the Caerphilly (/valleys/Cardiff) area ;-). Email to the address given here is rarely read, but if you swap "ae" for "MJAngove" you might get a response.

Hwyl!

M.

[N. Thornton]

If youre putting heavy loads on it, yes, but if it isnt running any

3kW heating devices then youre unlikely to need to upgrade it. Heavy loads would include washing machine, 3kW kettle (but not a 1.5kW one), 3kW fan heater, dishwasher, 6 slice toaster, basically anything that involves the full 3kW of heat output.

You could run a whole flat on 13A if you pick your appliances with enough care. Dont, but its been done.

Regards, NT