2 Single Ovens and a Hob !

[Justin991]

Just after a bit of info if thats ok! Having read earlier posts, there seems to be conflicting ways of doing what I need, hence the post. In the process of a new kitchen, and the new design will have 2 single ovens (a microwave combi and a standard oven), and a electric hob.

Rated as follows:

Hob - 5900w
Oven 1 - 3400w 13amp
Oven 2 - 3100w 13amp
Total: 12400w / 51amp

The existing load is a slot in cooker, thats rated at 10.7/44amp, the supplying circuit being just under 5 meters of 10mm cable, with a 40amp mcb 10.7kw (44amp) slot in cooker.

Can I do any of the following:

1. Taking into account diversity, from the Cooker Connection unit, one feed to the hob, one feed to FCU for 3400w Oven 1, then from that a feed to second FCU for lower rated 3100w Cooker 2. All cable being the same 10mm diameter, and all within a meter of the CCU.

2. As above, but change the MCB in the consumer unit from 40amp to 50amp?


Cheers!

 

[Steve]

Interesting one this. Assuming all those ratings are total possible currents, full load, it would be better to have a sub-main setup, since neither oven should really be oin a 13A plugtop - they are both over 13 amps.

Take the 10mm² cable from the CCU into a small consumer unit or DIN rain enclosure nearby (in the back of a cupboard?).

Fit a 30A, and two 16A MCBs for the appliances. Sorted. Then you can wire them in 4mm and 2.5mm cables.

As you're creating a 10mm² submain, the main MCB can be 50A.

 

[Justin991]

Interesting one this. Assuming all those ratings are total possible currents, full load, it would be better to have a sub-main setup, since neither oven should really be oin a 13A plugtop - they are both over 13 amps.

Take the 10mm² cable from the CCU into a small consumer unit or DIN rain enclosure nearby (in the back of a cupboard?).

Fit a 30A, and two 16A MCBs for the appliances. Sorted. Then you can wire them in 4mm and 2.5mm cables.

As you're creating a 10mm² submain, the main MCB can be 50A.

Yeap, I did think of doing it that way, but intrestingly both the combi oven and the standard oven both have moulded plugs! Thats why I suggested the original idea of using FCUs.

The ratings quoted are stated in the manuals as the absolute maximum total load. For example if using the combi oven just as a normal fan oven, the load is 1500w, not 3400w as stated.

As the ovens are physically supplied as 13amp devices by the manufacturer, and in use (with us at least!) would never be on full demand, would the original idea to take FCUs in series from the CCU not be ok taking into account diversity?

 

[Steve]

nothing in a house and mains electricity is ever wired in series.

But i know what you mean.

If they have moulded plugs, then fit 2 single sockets (not a double).

You dont need FCUs, because the sockets provide fuse protection, and the CCU provides isolation, providing it is within 2 metres.

Use a 40A MCB (little bit of diversity). Use 6mm cable to the sockets (you'll need good brand sockets to fit it in)