Kitchen Electrics

[Tinkler]

Help! I’m going to replace the kitchen ( wife) and need to re-do the wiring as I’ve found a spur from a spur situation. I‘ve also noticed that the kitchen is wired as part of the house ring-main. Knowing that it is best for the kitchen to have its own circuit; for practical reasons is it better to use a ring or a radial circuit? Currently it is wired with 2.5mm cable that I could extend/alter to form a ring; or I could create two radial circuits that would feed two halves of the kitchen. The second option is personally more appealing as it would for practical and aesthetic reasons mean not messing with the tiling (can’t see me find replacement tiles to match ) and knocking out too many channels in the plaster. As the wife has a penchant for doing everything in the kitchen at the same time, i.e. using cooker, washing machine, dryer, toaster, electric jug, microwave and the 'George Foreman' , would it be better to try to split the loading with the two radial circuits as opposed to the one ring? I understand that 2.5mm radial wiring has to be protected with a 20 amp rated MCBs and the ring would have a 32 amp. From a safety perspective which method would be more suitable particularly as I’ve worked out that if I went for the radial option the loading appliance wise (due to location) is imbalanced as it would be 1/3-2/3 – the 1/3 having a potential (everything running at once) current loading of 18 amps and the 2/3 of 33 amps at any one time. Can some bright spark please advise.

 

[Adam_151]

you can have a 32A radial circuit, you just need to use thicker cable than 2.5, 4mm is whats usually used, but in some situations 6mm might be required, and that would be difficult to terminate in the socket outlets.

I see nothing wrong with a radial each side (and it would be prefferble IMHO over rings, the current in ring legs can get out of balence in kitchens when heavy loads are grouped together towards one end...), got to decide what size radial you need though, oh and I'd put a separate 32A for the washing machine and tumbledryier if they are in the kitchen

 

[Tinkler]

you can have a 32A radial circuit, you just need to use thicker cable than 2.5, 4mm is whats usually used, but in some situations 6mm might be required, and that would be difficult to terminate in the socket outlets.

I see nothing wrong with a radial each side (and it would be prefferble IMHO over rings, the current in ring legs can get out of balence in kitchens when heavy loads are grouped together towards one end...), got to decide what size radial you need though, oh and I'd put a separate 32A for the washing machine and tumbledryier if they are in the kitchen

Thank you Adam for your advice. I was hoping to use the current 2.5mm cables to form the radial circuits, but it seems because of the size of the potential loading, 4mm cable would have to be the minimum size to go with. Also I think a single ring circuit (which can be formed as the wiring is presently) would not be adequate either. The problem is that I really do not want to touch the tiling and knocking channelling in the plaster would require this. I am hoping that I will be able to use the existing cable and capping in the walls to form the circuit – whether the capping will take the bigger 4mm cable is another matter!

It seems likely that in order to utilise the situation as it stands I may have to go with forming 2 (32 amp) ring circuits or having a combination of 1 ring and 1 (20amp) radial (this being on the half of the kitchen that has lesser loading). Your suggestion of a separate 32 amp feed for the washer and dryer is good but for the fact they are on opposite ends of the kitchen - the limited channelling opportunities on the walls and a concrete floor renders it unlikely unfortunately – I suppose using 13 amp FCUs in the feed to the 2 major appliances would help protect the cabling from potential overload. Can you tell me if there is problem with this and with having 2 different types of circuit in the same area?

 

[Adam_151]

No problem with having two different type circuits, just make sure they are labeled properly, like Kitchen "S/O radial #1", "kitchen S/O radial #2" rather than something vague like, "sockets"

I personanly would use 20A along the countertop each side, and have separate circuits for fixed loads, like the laundry appliances, and the oven, consider routing SWA cable on the outside of the wall, if you don't feel like channeling steel conduit into the floor...

 

[cozycats]

Another possibility is to use a 4 or 6 radial and then jb your existing 2.5 sockets to it. as LONG AS THE JBs ARE ACCESSIBLE!. If this enables you to retain the tiles! Not a conventional way in the UK but pretty standard in s.spain, and I can't see anything in the regs against it.

 

[Tinkler]

No problem with having two different type circuits, just make sure they are labeled properly, like Kitchen "S/O radial #1", "kitchen S/O radial #2" rather than something vague like, "sockets"

I personanly would use 20A along the countertop each side, and have separate circuits for fixed loads, like the laundry appliances, and the oven, consider routing SWA cable on the outside of the wall, if you don't feel like channeling steel conduit into the floor...

Thanks again Adam for your input.

 

[Adam_151]

Oh, and I probably ought to mention that this work is notifiable to your local building control, the way it should work is you should tell them what you plan to do, give them some money, and they'll make inspections that they deem neccessary, and will give you a building regs cert at the end, but unfortunatly its all a bit of a farce at the moment with them trying to shun there resposibilities, you have 4 choices,

1) ask LABC what they require and go along with it
2) play hardball and make LABC behave in the proper way
3) have a contractor regisistered to self cert carry out the work
4) ignore it totally, but still do the work properly

not trying to be a ******* , just sometimes people arn't aware of the new building regs, so just making sure

 

[Tinkler]

Another possibility is to use a 4 or 6 radial and then jb your existing 2.5 sockets to it. as LONG AS THE JBs ARE ACCESSIBLE!. If this enables you to retain the tiles! Not a conventional way in the UK but pretty standard in s.spain, and I can't see anything in the regs against it.

Is this really viable Cozycats? This would effectively mean that all sockets and FCUs are spurs on 2.5mm cable running off the 4mm radial cable - would this allow a further spur off any of the sockets? The JBs would be accessible as they would be in the loft - it is a single storey building. Would this method cope with the sort of loads mentioned in the initial post and what rating of MCB should then be used in the CU?

 

[Tinkler]

Oh, and I probably ought to mention that this work is notifiable to your local building control, the way it should work is you should tell them what you plan to do, give them some money, and they'll make inspections that they deem neccessary, and will give you a building regs cert at the end, but unfortunatly its all a bit of a farce at the moment with them trying to shun there resposibilities, you have 4 choices,

1) ask LABC what they require and go along with it
2) play hardball and make LABC behave in the proper way
3) have a contractor regisistered to self cert carry out the work
4) ignore it totally, but still do the work properly

not trying to be a ******* , just sometimes people arn't aware of the new building regs, so just making sure

Thanks for the advice Adam - I always take the 'P' very seriously

 

[ebee]

You cpuld make the radials 16A each, safer and might train "she who must be obeyed" to use less appliances simultaneously