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

 

[i=p/u]

That's If there is an internals fuse .

 

[Engineer54]

That's If there is an internals fuse .

Does it?? Where would the internal fuse(s) be located then, on say a hob and oven installation??

 

[telectrix]

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

briefly, a fixed load is not likely to overload a cable. the only time would be a short circuit, in which case the MCB in the CU provides s/c protection but not overload protection.

 

[i=p/u]

So is overload not a problem in op scenario . 2.5 joined with 6mm on 32A breaker .

And would your answer change if inductive load

 

[Engineer54]

So is overload not a problem in op scenario . 2.5 joined with 6mm on 32A breaker .

And would your answer change if inductive load

You mean like you'd find with an ''Induction Hob'' ...lol!!

Answer to your question then, is NO!!

 

[andy100]

briefly, a fixed load is not likely to overload a cable. the only time would be a short circuit, in which case the MCB in the CU provides s/c protection but not overload protection.

Appreciate all the responses, so telectrix are you of the same opinion as engineer54 in that a local enclosure in the kitchen is overkill and all that's required is a 32A MCB feeding both appliances with local switch isolation. I also spoke to Neff who said there are no internal fuses within the appliance themselves.

 

[Engineer54]

Appreciate all the responses, so telectrix are you of the same opinion as engineer54 in that a local enclosure in the kitchen is overkill and all that's required is a 32A MCB feeding both appliances with local switch isolation. I also spoke to Neff who said there are no internal fuses within the appliance themselves.

Jesus!! ....Did you honestly think that there would be??


Why do you think a made for purpose wall accessory in the form of a ''dual connection outlet'' (see link post # 13) is available on the market??

 

[andy100]

the only reason I thought there might be is because it shows the following details in the Technical data section of the manual:-

Power supply 220 - 240 V, 50 Hz
Maximum total connected load 3100 W
Microwave power setting 1000 W (IEC 60705)
Grill output power 2000 W
Hot air output power 1950 W
Microwave frequency 2450 MHz
Fuse 15 A

 

[telectrix]

think that's specifying the fuse you should fit.

 

[Guitarist]

In this case, manufacturers instructions are specifying 15A fuse or 16A MCB (one would assume). Personally, I wouldn't connect this directly to a 32A cooker supply.
Post #2 sums it up for me.

 

[Engineer54]

I wouldn't need to think twice about connecting these two appliances via a CCU and a dual connection outlet, if that's what was available!!

Why would you be complying with the manufacturers instructions which are based on non UK, European installations , which Neff generally do as a matter of course, with a little bit of fine print about following your own countries electrical codes?? So, how are you going to comply with the 15A fuse?? Say's nothing about 16A fuse or 16A MCB. Or maybe you are going to start changing/reverting things back to UK requirements again?? lol!!

If either of these appliances actually needed it's own OCPD then one would have been fitted.

 

[andy100]

Thanks all for your input, it's been really helpful!! Dual connection plate with 32A MCB it is!

 

[i=p/u]

But are you happy leaving 2.5 mm protected by 32A mcb

 

[telectrix]

i would be. read section 433 in bgb regarding providing short circuit protection only on a fixed load. specifically 433.3.1 (ii).

 

[i=p/u]

Just testing his confidence in deciding...