Spurring off cooker control unit

[tlangdon12]

Hello again

Thanks to those who answered my question on PIR/occupancy sensors for my downstairs toilet.

I have some questions regarding a flat I'm renovating. The flat is an ex-council property; imperial steel conduit, wired in singles, Wylex skeleton board in a Mantel cupboard, solid concrete floors and ceilings.

The Kitchen is very short of sockets. There at two single sockets at low level. The L-shaped worktop has one double socket at the far end of L. The only other socket is on the Cooker Control unit and serves the part of the worktop at the corner of the L and that's it!

I'd like to add some more sockets and am intending to get a local contractor to come and change the Wylex fuseboard for a Wylex FAL Consumer unit (2 RCDs), and give then this job. I just want to be clear what I should be asking for.

The Cooker circuit is wired in 6mm currently has a 32a MCB protecting it. The cooker has three elements (main oven 2.7kw, small oven 1.7kw, grill 2kw. total of 6.7kw or 27Aif no diversity applies). There is no RCD the current fuse board. I believe it would be possible to continue the 6mm cooker circuit (in 6mm) to a FCU with ?A fuse to feed a couple of double sockets. I appreciate there's not a lot of capacity on the circuit unless some diversity applies but I think I need to do something to increase the number of sockets and don't want a lot if making good to do. Neither am I a fan of mini-trunking.

The Cooker Control Unit is set into the top line of tiles. (There are just three rows of tiles above the work top.) I believe it would be a relatively simple job for the contractor to pop off this top line of tiles, and sink some 6mm T+E into the plaster to run to the FCU and continue in 2.5mm to a couple of flush double backboxes. (Approx 1m of 6mm & 1m of 2.5mm.)

My questions:

1. Can any diversity be applied to the cooker load to give me more than 5A for any additional sockets?
2. If some additional sockets can be added, would you feed them from the supply side of the FCU or from the Load side? (I was surprised to find that the switch for the socket on the CCU is in series with the cooker switch. It struck me that it might be more logical if the cooker switch isolated all the sockets fed from the CCU not just the one on the front.)

Thanks all

 

[itselectric]

Not something I would do, mainly because next man along could come and install a standard cooker then your 32amp fuse couldn't cope.

 

[stuartcourt]

just get some one in and do it properly, a small chase down from kitchen socket is all thats required and will save all the crap from above

 

[Darkwood]

No!- the kw rating of the cooker is over a threshold that requires its to have its own final circuit so you can't extend on it, considering its a kitchen which usually are the scene of many heavy loads it would be poor judgement and workmanship to do as suggested, as well as contravening the BS7671.

 

[Guest55]

why does the OP need answers to technical questions if hes hiring a pro ?
why not let the tradesman worry about the nuts & bolts of your electrical requirements ?


i call bullsh*t on the whole thread.

 

[stuartcourt]

why does the OP need answers to technical questions if hes hiring a pro ?
why not let the tradesman worry about the nuts & bolts of your electrical requirements ?


i call bullsh*t on the whole thread.

ha ha I second that

 

[Darkwood]

Yep seems a little strange to ask such a question when he will have an Electrician to hand who can view the existing set-up giving an advantage over the forum to possible solutions according to the set-up he finds.

Still a NO! you can't do it and advice you ask your electrician when he turns up about the options available to you.

 

[Clive P]

Hi,

Looked at a job for a friend on Monday ( another freebie ). Cooker hood had blown up, took that out to find supply was off Cooker Control Unit along with under cupboard lights; best bit was the 1.00mm flex off the live side of the switch feeding a socket. needless to say, will have to extend ring and do it properly. Everything else I've disconnected for now until I can go and do it. Was told done by " Electrician" ( done being the operative word ).

Regards.

 

[Badged01]

To add my two pennyworth to the debate and to stir up some further discussion ..........the BS7671 (Appendix 15) recommendation as a possible solution is that cookers over 2kW should have their own dedicated radial circuit and not be on a ring.

The logic behind this I believe was to avoid exceeding the CCC of ring circuit cable with a load slightly higher than the protective device for a long period of time, ultimately leading to conductor overheat/fire before the protective device 'pops'. (I think traditionally it has been assumed a ring is servicing everything in the house and if the cooker was on it at full pelt doing the Sunday roast, anything else connected such as an electric fire could produce this overload! Hence stick the cooker on a seperate circuit)

You could make an arguement that extending this radial circuit from the cooker that you already have (assuming the 6mm cables will fit into the cooker unit etc.....) falls outside this recommendation as its not on a ring. Especially if you assume that items used in the kitchen are unlikely to give a long current draw (Kettle, toaster, microwave etc .... ). Ultimately the MCB is there to protect the cable so in this configuration you could get nuisance tripping of the MCB with the load demand rather than a slow 'cooking' of the cable. (i.e cookers at full pelt and you make a cuppa with a few slices of toast)

Ultimately the designer of the circuit has to convince himself that it is safe to do the extension and it conforms with BS7671, before he does it and puts his signature on the relevant certificate.

Personally, I would put the cooker on its own circuit and run the sockets on another circuit -- but thats my interpretation of the regs, yours could be different!

 

[specs]

Not to much of a renovation if you can't chase a bit of floor or wall to get a proper kitchen ring in. How big is this flat ?New split board!! what is going into it 1X lights 1 X rest of the flat ring and a cooker radial ? with spurs running off it. Sorry but it just doesn't sound like a renovation to me. Seems whoever buys or rents this flat is going to spend a lot of time running back and forth to the cu resetting breakers while they are trying to cook and boil a kettle for a relaxing cuppa. I would love to see what the op's electrician has to say.

 

[ruston]

It's just lazy and shoddy,but typical of the type of installations you will see in "rented" accommodations.

 

[7029 dave]

It is a dedicated circuit for cooker end off

 

[specs]

It's just lazy and shoddy,but typical of the type of installations you will see in "rented" accommodations.

sadly you are so right, ive lost count of the flats my employers buy with the absolute basic installations. I often wonder how the tenants coped. It is nothing unusual to see sockets added run in trunking and smoke alarms run in trunking across ceilings. Looks lovely

 

[ruston]

Trunking, thats a luxury, whats wrong with clipped to the skirtings and around doors.

 

[longboat]

Yep seems a little strange to ask such a question when he will have an Electrician to hand who can view the existing set-up giving an advantage over the forum to possible solutions according to the set-up he finds.

Still a NO! you can't do it and advice you ask your electrician when he turns up about the options available to you.

Electricians are thin on the ground these day's.:dozey:

 

[specs]

Trunking, thats a luxury, whats wrong with clipped to the skirtings and around doors.

Have to agree, nothing better than a length of grey 2.5 clipped around a nice white skirting board, gives that arty touch to the magnolia walls, especially when the installer doesn't know how to run it in a straight line.:yes:

 

[ruston]

I think it looks better with 20 years of crusted gloss personally, can't beat a bit of mechanical protection.

 

[specs]

I think it looks better with 20 years of crusted gloss personally, can't beat a bit of mechanical protection.

Yep looks like it grew there.