Wiring Belling Cermaic Hob and Single oven...confused

[woochow]

Hi,

I've been trawling through these forums trying to find the answers I need, but I'm still somewhat confused. Thought it best to register and make a post.

OK. Kitchen has been gutted. There was no cooker connection switches. Fuseboard was very old 'fuse wire type'

Wife and me decided on having a built in oven and ceramic hob. Both by belling. Hob is model CRS60

Electrician came and installed new fusebox, re-earthed the place, and wired in cooker switch, we wanted this one:
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=48815&ts=27588

I asked about a separate cable connector box, I mean these:
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=47806&ts=27721

..for the cooker and hob, he said as it was all going to be built in, it wasn't absolutely nessaccery, assuming we didn't intend on changing things around - we don't.

Oven:
Belling XOU68MFSS7F can't find the power rating for the oven anywhere! Instructions are useless.
It says cable type should be: H05 V V-F 3x1.5mm2 what the hell cable is that? Does that mean 1.5mm wire? Speaker cable it sounds like
I tested it with 6mm twin and earth, direct to the cooker connection switch we had put in, worked fine, but it was a tight fit at the ovens connectors.
Q: Could I get away with 4mm for this connection?, or even 2.5mm?

ceramic Hob:
Belling CRS60 4 rings, rated at:
1x 2.1kw
1x 1.7kw
2x 1.2kw

Instructions here are even worse. Cable type recommended: H05V2V2-F 2.5mm2. Again, can this be right? I've read everywhere that at least 4mm minimum for a 6kw hob Am I not understanding the cable type they mean?

Q: Here I'm guessing that 6mm twin and earth is best, I haven't tried it yet. can I wire this direct to the http://www.screwfix.com/app/sfd/cat/pro.jsp?id=48815&ts=27588 with the oven? I imagine it would be a very hard fit to get two lots of 6mm cable into those connectors. Which is why I'd ideally use a 4mm, or even a 2.5mm for the oven, again, if that's ok to do?

Would using a separate ccu from the cooker switch to wire both apps into make the wiring easier? - Or are the terminals on the back of that just the same as the cooker switch ones?

Hope someone can help, as I wanted to get this done by today. Kitchen has taken me 2 months to gut and replace, and microwave and take-aways are taking there toll on my mind and body
Thanks.

 

[JohnD]

1) It's better practice to use a cooker outlet plate, as you showed, rather than wire the appliances straight into the switch, where the cables will be plastered and tiled over and very tiresome to change when, one day, you need to. It also has very large connection terminals under the cover.

2) the oven cable recommended is a PVC 3-core 1.5mm flex. This suggests it is a single oven. Single ovens usually take about 10A to 12A and can be wired into a 13Amp socket if you like, using the same flex you might use for a fan heater. If you want to use T&E I would go for 2.5mm. If you take that cable spec into an electrical merchant they will doubtless have flex to match it.

3) The cable recommended for the hob is a 2.5mm one which does indeed sound small.

However:
Cable sizing ought to be done according to the rating of the protective device. i.e. if you have a 20A MCB (or fuse) you can use smaller cable than if you have a 63A one.

If I were to guess, I would expect you to have a 32A MCB in your new CU, so you should be using 6mm PVC T&E or 4mm rubber or PVC flex

I am not too keen the oven and the hob being supplied from the same circuit. This is because the oven (probably) is rated at about 12Amps but you have protected it with a 32A MCB. A lot of people do it this way but IMO the oven ought to be on a 13A FCU or a 16A dedicated radial.

Also, a cooker switch without a socket is preferable. This is because cookers are better not on an RCD circuit, because they are prone to nuisance trips (and they are not portable appliances and cannot reasonably be expected to be used out of doors);but sockets ought to be RCD protected.

Let's see what other opinions we get.

 

[jj4091]

The cable code refers to the type of cable you require(flex pvc) & your elect. wholesaler will know what you need, if the oven manufacturers have recommended the cable size 1.5mm & 2.5mm as indicated in the code then that is what you need to use. If the cooker & hob connections are going to be out of site they need to be accessible, as you say a ccu would probably be the best answer.

 

[woochow]

Hi,
Many thanks for the very detailed and helpful replies

For my own clarification then:

1) - I can use 2.5mm T&E for the oven (it is a single, fan assisted oven, built under), and could wire direct to a 13 amp socket. This makes sense to me, as when I tested the oven by wiring to the cooker switch, I had to reset the timer everytime I switched the cooker switch on. So being 'spured' ( is that correct) into a 13 amp, it'll always be 'on' ?

2) - The hob, I should run on 6mm T&E, either to a cooker outlet plate, or direct to the cooker switch (though this is not so good for 'future proofing')?

Admitingly, to add a cooker outlet plate now, would be a slight pain as all the kitchen units which are under the cooker switch have already been fixed to the wall. Would it be bad practice to run a cable from the cooker switch, horizontaly left, say 20cm, then verticaly down to make a connection for the cooker connector plate? (under the wall of course) - I'm guessing that's not good practice though

The only 13 amp double plug socket I have close enough by for the oven, already has a spur (for the house alarm). Is it ok to connect another?

I'd also like any further suggestion regarding connecting both oven and hob to the cooker switch (with or without connecting plate). Does anyone else do it this way, or is it major bad practice to do it? It is the easiest way for me, and if I use, as suggested 6mm and 2.5mm, I'd be able to fit both cables more easily.

Thanks again for all your help.

 

[ricklthompson]

Hi

Just read about your wiring problem of the belling hob and oven, would you belive it ! i have the same problem!!!!

would you tell me what you ended up doing?

what type of wire did you use?
what fuse rating ?

Many thanks

Richard

 

[woochow]

Hi,

I completed this last summer. I wired the oven with 2.5mm T&E, and the Hob with 6mm, dirtect to the cooker switch (which has it's own fuse on the main board, not sure what amp it was now, 20amps perhaps, can't remember).

It all worked fine with no problems at all, and just the other week an electrician did a survey, and found it all fine.

The only problem I had was getting the wires into the Hob, and the cooker switch. The Belling ceramic hobs terminals are so small...trying to get 6mm in was tricky.

Hope that helps.

Oh, also, as far as I know, it'd be perfectly fine to wire the oven direct to a 13amp socket.

 

[ricklthompson]

Thanks for getting back to me with your answer.

Just one question? When you wired the HOB how on earth did you get the 6mm T&E in with wiring block? as they are bridging terminals already in place ?? do i have to remove any of them??

What type of cooker switch did you use??

Regards

Richard

 

[woochow]

Hi,
Yeah that was very tricky!! The bridging terminals should not be removed. The space for the cables is indeed very small, but it is possible to get them in. I remember it took me a few hours of cursing and sweating

The cooker switch I used is the one linked at the top of this page.

 

[ricklthompson]

Thanks for the advice,

Fitted the cooker & hob today, installed the hob using 6mm but changed the wiring stip connector inside the bottom of the hob for a slightly larger one, making it easier to fit install the 6mm and bridges together.

The cooker was installed by taking a spur off an existing socket using 2.5 T&E into a 20amp rated switched spur with a 13amp fuse.

All tested and working ok

Many thanks for you help.