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Could someone please clarify what is the correct way of replacing a freestanding electric cooker with integrated 6KW Hob and fan assisted integrated single oven (Wiring wise). Supply is 40 amp cooker switch with socket.
Regards
SimonRe: Wiring a Hob and oven
I normally use a junction box & wire both appliances into it, the cable to hob & oven need not be any bigger than 4mm, most hobs and single ovens actually have 2.5mm cable on them. I do think that in theory both appliances should have a separate switch for isolation purposes but not all houses a wired like that. Please kitchen fitters leave enough cable to service appliances.
Re: Wiring a Hob and oven
It is dangerous to under-rate the cable. See tables below which I hope may help. To calculate the amps divide the (total)Watts on the rating plate by 230 (i.e. the voltage). So 6KW is 6000 watts, divided by 230 gives a tad over 26 amps.
Some single ovens (not all) can be wired with 2.5mm flex (heatproof preferably) or flat cable because they take under 3KW in power consumption.
I rewired many houses including kitchens and always used 6mm as a standard for convenience.
Coming out of the 45-amp Cooker Switch on the wall, you can go into a 30 or 40 amp round junction box firmly attached to wall or cupboard, and split out into hob and oven seperately, or you can go into one appliance and then loop out to the second. Most commonly I have looped into the hob, and then out to the oven, but sometimes there is more room for the two cables in the oven.Note that the fuse in the consumer unit (fusebox) must be lower in rating (amps) than the thinnest cable used. A 30 amp fuse will not stop a 2.5mm cable from melting or catching fire if you run 30 amps continuously thro it! That is why some single ovens wired with only 2.5mm flex should have a 13-amp fused plug on the end and plug into a standard wall socket.
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Table 1 = Method 4 Encased in insulated wall
Cable size Rating in Amps2.5mm 18.5
4.00mm 25
6.00mm 32
10.00mm 43Table 2 = Method 1 Clipped Direct
Cable size Rating in Amps2.5mm 27
4mm 36
6mm 46
10mm 63
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I hope this helps (I cannot of course be held responsible for the accuracy of the above…etc.etc)Mike
Re: Wiring a Hob and oven
myfil wrote:or you can go into one appliance and then loop out to the second. Most commonly I have looped into the hob, and then out to the oven, but sometimes there is more room for the two cables in the oven.
Haven`t done any installation work for years but certainly don`t like the idea of linking these appliances at their mains terminal blocks.
You would be adding the current drawn by these appliances through the mains terminal block and if you did this you have an overload situation.
Doubt it would even be possible to get two 6mm cables into either hob or oven terminal block and shouldn`t be considered anyway.Bryan
Re: Wiring a Hob and oven
a lot of hobs recommend wireing in 2.5 d i y stores even sell heatproof 2.5 flex labled as for hobs 🙄
still seems too small for me diversity of use or not! If I remember correctly its OK to use one isolator for both hob and oven if it and the units are within 1.5 m check in the regs or one of the regs guides to be on the safe side that said how many new houses have you been in to find the isolator on the other side of the kitchen or even inaccesablewilf 🙄
Re: Wiring a Hob and oven
try this
an extract from http://www.tlc-direct.co.uk/book/6.5.2The Electricians Guide
more information on loading factors at web site, cable size dependant on loading
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6.5.2 – Cooker circuitsA cooker is regarded as a piece of fixed equipment unless it is a small table-mounted type fed from a plug by a flexible cord. Such equipment must be under the control of a local switch, usually in the form of a cooker control unit. This switch may control two cookers, provided both are within 2 m of it. In many cases this control unit incorporates a socket outlet, although often such a socket is not in the safest position for use to supply portable appliances, whose flexible cords may be burned by the hotplates. It is often considered safer to control the cooker with a switch and to provide a separate socket circuit. The protective device is often the most highly rated in a’) installation, particularly in a domestic situation, so there is a need to ensure that diversity has been properly calculated (see Table {6.2}).
The diversity applicable to the current demand for a cooker is shown in {Table 6.2} as 10 A plus 30{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} of the remainder of the total connected load, plus 5 A if the control unit includes a socket outlet. A little thought will show that whilst this calculation will give satisfactory results under most circumstances, there is a danger of triggering the protective device under some circumstances. For example, at Christmas it is quite likely that both ovens, all four hotplates and a 3 kW kettle could he simultaneously connected. Just imagine the chaos which a blown fuse would cause! This alone is a very good reason for being generous with cable and protective ratings.
Graham
LeicestershireRe: Wiring a Hob and oven
Presuming the oven is a standard 3kw unit, if a fault occurs in the oven it now has to blow a 40 amp fuse.
Given that a free standing cooker is going and the replacement is a built-in, it springs to mind that a good deal of work is occurring in the kitchen with the installation of worktops and cabinets.
I think it would be best to channel the wall down behind the new worktop and cabinet, feeding 6mm T&E from the cooker switch to a new cooker switch with 13 amp socket behind the oven. The new cooker switch could then feed the hob and the 13 amp socket feed the oven from a standard 3 pin plug.
The only kick up the backside for doing it the “correct” way is Part P compliance for extending the circuit.
If you do it the easy and potentially hazardous way, there is no circuit being extended and so no Part P reporting…………… stupid isn’t it!!!!Cookerfit
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