Installing cooker and microwave oven

[Centurion]

I am refitting a kitchen and installing a Neff Cooker and Neff microwave combination oven and have received conflicting advice regarding the installation. The shop providing the appliances advised that we should cable each item seperately to a cooker control unit via fused switch units. Yesterday, the electrician we have asked to connect the items advised that all we needed was a cooker unit with a socket for the microwave.

I took the electricians advice and bought the necessary items but my wife (who knows a thing or two about these matters) had a sleepless night and I have undertaken to reassure her! So any reassurance/advice would be most helpful.

Technical specifications are:

The oven:

Total connect load: 5.9kw

The microwave oven:

Power supply: 230V, 50Hz
Total connected load: 3.2kw
Microwave output: 1000W
Radiant grilling: 2000W
Hot air: 1950W
Frequency: 2450 Mhz

The microwave has a cable but has no plug. The installation notes state the lead must be protected by a 16 AA-type fuse (L-type/B-type MCB).

We had a new consumer unit fitted last year and have a 6mm cable connection that was previously fitted to the old cooker.

The oven and microwave will be located one above the other in a tall unit with a cupboard over the top. The electrician advises that we can place the control units in the cupboard but this appears contrary to all written advice I have seen which says the control units should be to the side. Again, your advice please?

Please note there was a very similar question asked on the forum in 2004 but the microwave output was less and the response not conclusive.

Thank you.

 

[JohnD]

"The oven: Total connect load: 5.9kw"
"The shop providing the appliances advised that we should cable each item seperately to a cooker control unit via fused switch units."

This does not sound right. An FCU has a 13A fuse in it (or lower) but 5.9kw is about 25Amps, so when drawing max power would reliably blow the fuse, if you mean this is the load of the big oven on its own. Is it a double oven, or an oven plus independent grill? It sounds quite big.

Microwaves are generally OK through a 13A plug, or a 13A FCU if you prefer. 3.2kW is a little higher than usual but should not give trouble.

You do not mention a cooker or hob, just the ovens, so perhaps you have a gas hob that does not need a significant electrical supply?

I am convinced that the switch should be beside the cooker in plain view but I am also listening carefully to other opinions.

 

[Centurion]

Thanks for the prompt response.

The total connected load for the oven is 3.7kw. I read the specification for the double oven (with the same number) by mistake - sincere apologies.

We do have a separate gas hob on the ring main.

 

[JohnD]

3.7kW is 3700Watts. Divided by 230Volts would be 16Amps though actual voltage and current vary a bit. Funnily enough, it would be OK on a 13Amp fuse, because ovens cycle on and off with their thermostats, and don't often take full power for long.

So this could also go on an FCU or even a plug if you wanted to.

But there is nothing wrong with putting it through your Cooker switch, indeed, this is probably preferable because you might later have the urge to fit a double oven (which would be too much for a 13Amp fuse)

As often happens, there are multiple different acceptable ways of doing the job.

It is quite usual to have the connector behind the oven, but the switch should be in plain view and accessible. The big Cooker switches "Cooker Control Unit" usually have the switch up on the wall and a cable connector behind the cooker.

 

[Centurion]

Thank you.

I understand it is okay to connect the cooker (3.7kw load) to the cooker control unit and to plug in the micro combination oven (3.2kw load) to the same control unit.

Regrettably the good lady is still not reassured. She asks does using the above configuration in any way inhibit the use of both appliances at the same time.

You say there are multiple acceptable variable ways of doing the job. Our ideal solution would be to have one cooker unit (no plug). Then to have separate cables to fused switches to service each oven?

In the light of your earlier reply we would put the cooker unit on the wall at the rear of the units with the switches in the overhead cupboard.

 

[JohnD]

Regrettably the good lady is still not reassured. She asks does using the above configuration in any way inhibit the use of both appliances at the same time.

No.

You say there are multiple acceptable variable ways of doing the job. Our ideal solution would be to have one cooker unit (no plug). Then to have separate cables to fused switches to service each oven?

I think these would be two fused connection units with flex outlets, fed from the cooker radial. No prob. that I can see if you like it that way. As they have fuses in them put them where they are easily accessible if you ever need to change the fuse.

If you are having it done by a qualified electrician (as you should, because it's in a kitchen and it would save you the trouble and expense of involving Building Control at your local council) describe your preference and ask if it looks right to him.

 

[Centurion]

JohnD, thank you for your time and patience. The good lady is now suitably reassured. This is my first post on the forum and I'm most appreciative of the service

For the record, the job is being done by a qualified electrician - and I am delighted you have endorsed his recommendation. My role is simply doing all the preparatory work and keeping her indoors happy.

Many thanks

 

[Centurion]

Sorry, one last point. The good lady has drawn my attention to a yellow warning tag attached to the micro oven cable which states the following:

"The power rating of this appliance requires a supply of 15A or more via a switched cooker point, double pole isolator having a minimum 3mm contact separation, placed in an easily accessible position.

This appliance must NOT be connected to the mains supply by means of a 13A plug."

Our intention was to connect it to a switched cooker point via a 13A plug as previously advised. In the light of the above warning is this okay?

 

[JohnD]

You should have torn the tag off before she saw it!

13A fuse... 15A MCB... the difference is unlikely to show.

I have a feeling the oven might have been designed for use in a country that doesn't use our wonderful 13A plugs?

Apart from giving it a separate radial, I can't think of how to do it without a teeny CU in place of the cooker switch, turning the cooker radial into a sub-main.

I wonder if someone else knows a tidier way?

 

[Adam_151]

I'd run a cable from the cooker connection point to a mini CU with a couple of 16A breakers, tuck that away in the back of a cupboard, out the way, but accesable, and run some suitably rated heat resistant flex to the appliances from stuffing glands in the mini CU. Or to a if there is enough room behind the apllicances, to a BS546 outlet located near the appliances

The cooker switch would stay above the countertop and visable next to the appliances, and the cooker connection point would be below the counter top supplying the mini CU (conventional setup, makes it easier for the next person who wants to change the cooker, etc)

(if you have electrical ignition for the gas hob, you could run that off a 3A breaker in the mini CU as well)

 

[Steve]

Ey up! everybugger's nicking my ideas now

 

[JohnD]

Ey up! everybugger's nicking my ideas now

Irritation is the sincerest form of flummery.