Replacing Oven/Hob - Located in a breakfast bar island

[sergeantash]

In my kitchen, I have an electric oven unit with integrated ceramic hob currently sat in my breakfast bar island - I'm getting rid of that and replacing it with a new built-under oven and a separate new Induction hob set into the worktop directly above the new double-oven.

At present, the oven is powered by a 7mm cable through the floorboards directly below the current unit and straight back to the CU (dedicated non-ring circuit). The cable is wired straight into the back of the oven, there is no dedicated switching for the oven in the kitchen.

The oven I have bought states:
Electrical Connection: 4.9KW

Induction Hobs of appropriate specification (not bought yet) state:
Electrical Connection: 6.6kW

This dedicated circuit has a 32amp MCB in the CU, also the CU is RCD protected.

What is required to correctly terminate this cable within the void and to then provide power to the new oven and also to the hob directly above?

Thanks in advance!

 

[PrenticeBoyofDerry]

7mm cable is not a standard.
Is it 6mm or maybe even 10mm?
Applying diversity, it is possible to have up to 15kW rated power of appliances on 32A circuit, ideally 6MM cable providing there is no de-rating factors of cable (conduit, trunking, thermal insulation) along the route.
I would suggest that some local isolation is provided though.
You can have the supply cable feeding a double outlet box, you could then take a split circuit one to hob and one to cooker. Either have isolation between split and appliances therefore, individually isolated or isolator before dual connection, there isolating both appliances.

 

[sergeantash]

7mm cable is not a standard.
Is it 6mm or maybe even 10mm?
Applying diversity, it is possible to have up to 15kW rated power of appliances on 32A circuit, ideally 6MM cable providing there is no de-rating factors of cable (conduit, trunking, thermal insulation) along the route.
I would suggest that some local isolation is provided though.
You can have the supply cable feeding a double outlet box, you could then take a split circuit one to hob and one to cooker. Either have isolation between split and appliances therefore, individually isolated or isolator before dual connection, there isolating both appliances.

Sorry, you're absolutely right, I just checked the cable and it is indeed 6mm.

The cable run is only 4 meters from the CU and I have traced the cable and it is in good condition, no break/repair or junction boxes along the way

Your suggestion sounds good to me, I think the isolation before the split will make sense as if work was being carried out to one or the other I'd prefer a central on/off isolation for both.

Based on 6mm, could you guide me with TLC components that I'll need to order to achieve this?

 

[PrenticeBoyofDerry]

The cable run is only 4 meters from the CU and I have traced the cable and it is in good condition, no break/repair or junction boxes along the way

A visual inspection is a good start, but I would also suggest doing the continuity and insulation resistant tests to confirm condition of cable.

Based on 6mm, could you guide me with TLC components that I'll need to order to achieve this?

http://www.tlc-direct.co.uk/Products/CB4016slash3.html
http://www.qvsdirect.com/45A-Dual-Connection-Plate-pr-22880.html
TLC don't seem to do dual outlet plates.
You will also require back boxes I assume they will be surface mounted.
http://www.qvsdirect.com/45A-Dual-Connection-Plate-pr-22880.html

 

[sergeantash]

The cable run is only 4 meters from the CU and I have traced the cable and it is in good condition, no break/repair or junction boxes along the way

A visual inspection is a good start, but I would also suggest doing the continuity and insulation resistant tests to confirm condition of cable.

Based on 6mm, could you guide me with TLC components that I'll need to order to achieve this?

http://www.tlc-direct.co.uk/Products/CB4016slash3.html
http://www.qvsdirect.com/45A-Dual-Connection-Plate-pr-22880.html
TLC don't seem to do dual outlet plates.
You will also require back boxes I assume they will be surface mounted.
http://www.qvsdirect.com/45A-Dual-Connection-Plate-pr-22880.html[/QUOTE]

Good plan, I still may even swap the cable for new considering it's such a short run.

I'll order up these bits and keep you updated. Thanks again.

 

[sergeantash]

Just to confirm - is there any reason why I shouldn't sit this isolator and connection unit behind the plinth at floor level (essentially under the oven) so that I can isolate the appliance without having to pull it out of the island void? Unfortunately there isn't a suitable cupboard eitherside into which I can place it.

 

[PrenticeBoyofDerry]

It's not the ideal location for isolation, but much better than installing it behind the appliance, as if the casing of the appliance became live and other safety devices failed, you would need to remove the appliance to isolate, which is not particularly appropriate, given that the casing is live.
If you are installing new cables, I would suggest you find a suitable location within the kitchen, where the isolator can be fitted above work top height.
Please note that cable must be routed within permitted safe zones if buried in wall.
Look in Wiki installation techniques
If you do install a new cable and then decide to increase the protective device rating, it would be deemed as a new circuit.

 

[sergeantash]

It's not the ideal location for isolation, but much better than installing it behind the appliance, as if the casing of the appliance became live and other safety devices failed, you would need to remove the appliance to isolate, which is not particularly appropriate, given that the casing is live.
If you are installing new cables, I would suggest you find a suitable location within the kitchen, where the isolator can be fitted above work top height.
Please note that cable must be routed within permitted safe zones if buried in wall.
Look in Wiki installation techniques
If you do install a new cable and then decide to increase the protective device rating, it would be deemed as a new circuit.

Thanks again, really appreciate your great help.

I've had a think about it, and I'm going to try and find a nice brushed chrome DP switch instead and mount it on the back of the breakfast bar (the worktop overlaps slightly so I can fit this right at the top and it won't be seen from someone's standing height) - it is then also very accessible.

Thanks again!

 

[Iggifer]

http://www.screwfix.com/p/lap-2-gan...13a-switched-plug-socket-brushed-chrome/30288

there's a few on there:

http://www.screwfix.com/c/electrical-lighting/cooker-switches-45a/cat4440002

 

[sergeantash]

http://www.screwfix.com/p/lap-2-gang-45a-dp-cooker-switch-13a-switched-plug-socket-brushed-chrome/30288

Ah, thats perfect as an additional socket would be useful at the end of the breakfast bar!

I'm struggling to find a suitable 45amp connection unit on Screwfix though (handy as I can head to my local store today), I spoke to TLC and he commented that he hadn't been asked for one (a 45amp connection unit) in 25 years of working in electrics!

 

[EFLImpudence]

Enter 'cooker connection unit' into the Screwfix search bar.

 

[sergeantash]

Enter 'cooker connection unit' into the Screwfix search bar.

I can't find within those results any unit which looks appropriate for 3 connections (1 x source, 2 x load).

 

[PrenticeBoyofDerry]

http://www.screwfix.com/p/lap-2-gang-45a-dp-cooker-switch-13a-switched-plug-socket-brushed-chrome/30288

Ah, thats perfect as an additional socket would be useful at the end of the breakfast bar!

Remember you will require 150mm from centre of socket and worktop, to offer the plug and attached flex adequate protection from stress damage, you don't want a socket within 300mm of the hob, you don,t want to be reaching over hob to use isolator.

I'm struggling to find a suitable 45amp connection unit on Screwfix though (handy as I can head to my local store today), I spoke to TLC and he commented that he hadn't been asked for one (a 45amp connection unit) in 25 years of working in electrics!

Screwfix don't do dual outlets, might be worth going to a wholesalers and TLC chap obviously doesn't either listen or talk to customers a right lot.

 

[sergeantash]

Remember you will require 150mm from centre of socket and worktop, to offer the plug and attached flex adequate protection from stress damage, you don't want a socket within 300mm of the hob, you don,t want to be reaching over hob to use isolator.

Sorry I think that I confused you with what I wrote. I intend to install this socket on the opposide side of the island/breakfast bar, so to isolate or to plug in an appliance, I would walk around the breakfast bar and it'll be mounted vertically on the rear blanking panel of where the oven void is.

So if you imagine, at the back of the oven void is a blanking panel (visible from the other side of the breakfast bar), so I'd be installing the socket into that blanking panel.

 

[PrenticeBoyofDerry]

Sorry I think that I confused you with what I wrote(I was never confused)..........so I'd be installing the socket into that blanking panel.

Okay my mistake, so the other thing then would be, trailing flexes from socket if no worktop, watch out for that.