Help! Supplying two ovens from a single radial

[andy100]

Hello,

I have a 6mm t&e protected radial circuit running from the CU to the kitchen, this was originally going to feed just a new Neff Oven, rated at 3.68KW total connected load ~ 16Amp. This was fine, but now it turns out that the new Microwave we’re getting is rated at 3.1KW total connected load and the technical specs state it should be protected at 15Amps. The Microwave was originally going to be less powerful and would have been able to connect into a 13Amp FCU off of the mains ring but now I have the problem that I have a single 6mm t&e radial that I need to feed both appliances. I have seen the appendix on the 17th ed and know this is allowed.

I have a 32Amp MCB which will protect the 6mm cable and allow enough current to supply both appliances but I’m concerned about short circuit protection for the appliances themselves as well as protecting the 2.5mm flex tails that will run from the isolator switches to the appliances. Any advice would be much appreciated.

Thanks

Andy

 

[telectrix]

fit a 2.5mm to each oven.fed from 2 16A MCBs in an enclosure in the kitchen.

 

[andy100]

Thanks telectrix for the quick response. Do you think I would still need 2 all-pin isolation switches as well or would the main switch within this new enclosure be sufficient for maintaining an all-pin isolation although it would be for both appliances at the same time.

 

[Guitarist]

Thanks telectrix for the quick response. Do you think I would still need 2 all-pin isolation switches as well or would the main switch within this new enclosure be sufficient for maintaining an all-pin isolation although it would be for both appliances at the same time.

Guessing that you're not a domestic electrician

 

[Engineer54]

If the 6mm cable is supplying a CCU, then just fit a dual connection plate and connect both appliances to that. I take it that the hob is Gas??

 

[i=p/u]

Think he's on about the 2.5 flex e54 .

you could change the flex too 4mm ..

 

[andy100]

thanks engineer54, at the moment, instead of using a dual connection plate, I'm just using a 60amp junction box (as this is big enough to get 3 x 6mm into it)
In = 6mm from CCU
Out = 2 x 6mm to feed each isolator switch then 2.5mm flex to each appliance.

Correct me if i'm wrong, but a dual connection plate still doesn't resolve my issue of short circuit protection for the appliance itself and cable protection (2.5mm flex). Even if I used 4mm flex as i=p/u suggested, the weakest link just moves to the internal wiring of the appliance itself and more importantly the appliance.

thanks for your feedback so far.

Also hob is induction but on a separate circuit.

 

[i=p/u]

Well what does manufactured instructions say, maybe you you to try telectrix idea and add small enclosure if you don't want to remove flex...

 

[Engineer54]

thanks engineer54, at the moment, instead of using a dual connection plate, I'm just using a 60amp junction box (as this is big enough to get 3 x 6mm into it)
In = 6mm from CCU
Out = 2 x 6mm to feed each isolator switch then 2.5mm flex to each appliance.

Correct me if i'm wrong, but a dual connection plate still doesn't resolve my issue of short circuit protection for the appliance itself and cable protection (2.5mm flex). Even if I used 4mm flex as i=p/u suggested, the weakest link just moves to the internal wiring of the appliance itself and more importantly the appliance.

thanks for your feedback so far.

Also hob is induction but on a separate circuit.

Short circuit protection is afforded by the 32A MCB. The appliances are fixed equipment so the flex's/cords cannot overload. So there is absolutely no need to go to the lengths you seem to be going too...


What's more, accessory fuses are there to provide protection for flex/cords, NOT the appliances themselves. If these appliances were portable/moveable then yes you would need a fused plug top or FCU, but not absolutely necessary where fixed appliances are concerned...

 

[telectrix]

433.3.1 (ii). i believe.

 

[i=p/u]

Wish had me book to read that reg . I have change flex to 4mm in past in this scenario

 

[i=p/u]

So you'd be happy connecting 2x 2.5mm cables to 6mm . What's that reg in brief tel.

 

[Amp David]

Fit one of these and job done.

Polar 45A Dual Appliance Outlet Plate - Bright White


The search on the forum works too you know

 

[i=p/u]

Well as I read it , it's fine as todo with fault current and overload on resistive loads...

 

[Engineer54]

So you'd be happy connecting 2x 2.5mm cables to 6mm . What's that reg in brief tel.

If 2.5mm cords not over 3m, i can't see a problem, ...can you??