kitchen oven wiring

billy.whizz

billy.whizz

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Please can anyone tell me about wiring a combine oven /microwave?. we have an enclosed combo oven microwave. which im renewing, there is a junction box and wiring already there from the previous one. but the oven is fed from the junction box as normal, but the microwave is fed from the oven, it doesnt have its own switched/junction box like the oven . is this ok? many thanks for looking.
 
billy.whizz said:
Please can anyone tell me about wiring a combine oven /microwave?. we have an enclosed combo oven microwave. which im renewing, there is a junction box and wiring already there from the previous one. but the oven is fed from the junction box as normal, but the microwave is fed from the oven, it doesnt have its own switched/junction box like the oven . is this ok? many thanks for looking.
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As far as I know electric oven cable needs to be 6mm cable, the conductors in the cable the live and neutral should be 6mm in diameter including the sheath, the earth is usually a bare wire the runs between the live and neutral. I would imagine that if the original built in oven/microwave had just the one feed then the single spur feed should be Ok.

Behind our oven/hob cooker there is a single spur point that feeds it, above the worktop is a switch point that has a neon indicator and a switch that has "Cooker" on it and in the mains-in cupboard there is a circuit isolator for the cooker.

I am sure someone with more electrical knowledge will be along soon and I'll stand to be corrected.
 
If the microwave is spurred off the oven feed then it should have its own fused spur rated for that application. And the whole circuit need to be rated for both applications running together.
 
billy.whizz said:
Please can anyone tell me about wiring a combine oven /microwave?. we have an enclosed combo oven microwave. which im renewing, there is a junction box and wiring already there from the previous one. but the oven is fed from the junction box as normal, but the microwave is fed from the oven, it doesnt have its own switched/junction box like the oven . is this ok? many thanks for looking.
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Got a picture buddy?
 
I'm sorry I don't have any photos, but yes its just an oven mounted in a kitchen unit and above it is a microwave made by the same supplier.
 
The oven/microwave combo are linked together and 1 feed too the oven and microwave spurred off the oven, what I'm doing is replacing the oven/microwave with a new one .
 
The oven has the correct wiring and junction box and separate fused on the RCD , the microwave which is housed above it takes its feed from the oven
 
It's running of a 6 mm cable and correct fuse on the board yes a cable runs from the back of the oven input.
 
billy.whizz said:
It's running of a 6 mm cable and correct fuse on the board yes a cable runs from the back of the oven input.
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Yeah thats NOT right.

I expect that as the oven supply is for the old freezer standing units which required a much greater supply than newer built in ovens that are generally only demanding 13amps. Plus the 13 amps the microwave can drawer is still a safe load for the cable and wont cause the breaker to trip.

The problem is the microwave cable is not correctly protected, and it sounds like the unit cannot be isolated in an emergency.

As it's a kitchen corrective works should be undertaken by a professional.

Sorry chap.
 
There should still be a double pole isolator near the oven itself. You say the dedicated radial from your consumer unit is 6mm and this T&E should be terminated into a 45A DP isolator switch in your kitchen. A smaller 3 core heat resistant flexi cable would then typically feed your oven (1.5mm/2.5mm max as even 1.5mm is rated to 16A). You would not normally terminate a dirty great 6mm T&E directly into an oven.

Your existing arrangement should have the feeds for both the oven and the microwave taken from the local DP isolator and your new arrangement definitely should. I have 2 ovens and although I chose to install 2 isolators it's not really necessary one will do. Main thing is that the radial is sized correctly for the load and this comes down to the rating of your appliances and the length of the cable run and how it is installed. There are online tools you can use to check this but as long as you are replacing the appliances with ones rated the same or lower the likelihood is you are going to be OK.
 
Your going to get a 1001 answers to this unless you can show pictures of the appliances and ratings
I know kitchen units that are made to fit an oven and microwave in the same unit, but I haven't come across a manufacturer that has both fitted together as one appliance
Is sounds to me that someone has bodged the wiring of what you have fitted.
Ovens on their own don't need a 6mm cable if their wattage is below a certain level. But ''cookers'' that is an oven and a hob combined are normally connected on their own radial circuit that goes back to the consumer unit with a 6mm cable, or bigger if it is a range cooker.
Sounds to me that your set up at the moment was not connected by a qualified electrician.

Without looking at it and dependant on the load that your new appliances take, a double socket could be fitted to the 6mm cooker cable and the microwave and cooker could be plugged into that using a 13a plug on each appliance , once again that is dependant on their load, and especially the oven and only if that cable is only feeding those two appliances and has an isolating switch within 2m of them and a 32a fuse/mcb/rcbo in the consumer unit
 
ColinD said:
Your going to get a 1001 answers to this unless you can show pictures of the appliances and ratings
I know kitchen units that are made to fit an oven and microwave in the same unit, but I haven't come across a manufacturer that has both fitted together as one appliance
Is sounds to me that someone has bodged the wiring of what you have fitted.
Ovens on their own don't need a 6mm cable if their wattage is below a certain level. But ''cookers'' that is an oven and a hob combined are normally connected on their own radial circuit that goes back to the consumer unit with a 6mm cable, or bigger if it is a range cooker.
Sounds to me that your set up at the moment was not connected by a qualified electrician.

Without looking at it and dependant on the load that your new appliances take, a double socket could be fitted to the 6mm cooker cable and the microwave and cooker could be plugged into that using a 13a plug on each appliance , once again that is dependant on their load, and especially the oven and only if that cable is only feeding those two appliance and has an isolating switch within 2m of them and a 32a fuse/mcb/rcbo in the consumer unit
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As it's in a kitchen it cant be done by a competent person though iirc, or rather it can, because he must be qualified?
 
ColinD said:
a double socket could be fitted to the 6mm cooker cable and the microwave and cooker could be plugged into that using a 13a plug on each appliance ,
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Most double sockets are rated for 13A in total (design load of 20A max with diversity) not 2x 13A without diversity. Would be better to terminate the 6mm into a suitable JB then install 2 single sockets if going down this path.
 
billy.whizz said:
@ColinD ,,, @Matt@Nearfield , and all the other guys who replied ,,thank you for your help and the really helpfull information. going on whats been said i think that i will steer away from this one ,even though its for family, and get a qualified electrician in to sort it out. thank you all.
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Good call - don't bite off more than you can chew. It's amazing how big some supposedly small 'love' jobs become once you get started.
 
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