Ok to add socket for microwave?

[Boilerman2020]

Away now until next week, from memory they're all General Electric, box included

 

[flameport]

It's a built in microwave though

How often do you expect the microwave to go wrong?
Removing two screws and pulling the microwave out once a decade isn't a problem.

 

[FrodoOne]

In that case, the circuit is already at its limit. A new circuit would be best.

Add at least one new Radial Circuit for the Kitchen and leave the Fridge on the "Side-Lounge" circuit.

North Americans are often accused of having too many separate circuits - for their (mainly) 120 V (high-current) AC.
(Built-in Microwave Ovens in North America are REQUIRED to be on an individual [15 A - or 20 A] circuit.)

However, those in the UK seem to have too few separate/independent circuits.
Any modern UK Kitchen should have at least two separate 20 A circuits and it would be preferable if the Fridge were not on one of those but on a different low load Lounge/Bedroom/Other 20 A circuit.

All circuits should be supplied via RCBOs.

 

[Boilerman2020]

Maybe the Fridge and / or boiler could be put on to the immersion circuit - it draws approx 12.4A (a 2.85kw element) through 2.5mmsq protected by a 20A, so there would appear to be room for it - but does this go against regs? They are all fixed permanent devices with switched isolator units, if there's space then why not.

FrodoOne I don't know how they would add another B20 circuit due to board space.. although, there are a lot of B10 lighting circuits using very few lights, maybe could amalgamate two of those circuits on to one 10A, and swap out the 10A for a 20A which could then take the fridge and/ or boiler. Doesn't the fridge use very little power anyway, about 0.4A?

 

[Ragnar_AT]

I know it‘s frowned upon but both the fridge and the boiler could very well run on a lighting circuit. Both are very small loads.

 

[EFLImpudence]

...but is it frowned upon to have some lights on a fridge/boiler circuit?

 

[Boilerman2020]

As promised. There's no room for another B20 on the top rail unless the busbar was extended.

 

[EFLImpudence]

As promised. There's no room for another B20 on the top rail unless the busbar was extended.

Well - not exactly - there is plenty of room.

 

[plugwash]

North Americans are often accused of having too many separate circuits. However, those in the UK seem to have too few separate/independent circuits.

One 32A socket circuit (plus a seperate cooker circuit if the cooker is electric) has worked just fine for UK kitchens for donkeys years.

 

[AndyPRK]

Can fast boil our kettles for tea and turn our electric hobs on too

 

[Boilerman2020]

I suppose everything is bigger in America!

So it looks like some of the appliances could be moved on to a new 20A there, hopefully stress free. FrodoOne, are you sure it would need to be a RCBO? Wouldn't a usual Type B single pole suffice.

 

[SUNRAY]

Hello Everyone,

I just want to make sure I'm ok adding this new socket for a microwave.

I plan on putting in a single socket on a 13A fused switch and linking it as a spur from the existing radial circuit. It will be in 2.5mm2 T+E, running from a circuit which is protected by a 20A circuit breaker. The cable will be run in surface trunking over tiles vertically and across in to a cabinet, all sealed safely. On the board, it shares a 63A RCD with four other 20A fuses.

I have attached a diagram showing what is already on it.

View attachment 334860

Thanks for the good sketch and pic.
To my mind the most obvious thing to do is run a 2.5mm² cable from your new Microwave FCU back to the consumer unit and convert it into a ring.
Install a new 32A RCBO in the vast spare space which is not on either of the existing RCD's. It wouldn't matter too much what make as there is already a selection of devices in there.
That will also reduce anxiety about the size of the RCD.
However I'm not there and cannot see the routes or difficulties involved.

EDIT: making changes to and within a consumer unit is not a DIY job.

 

[Boilerman2020]

Thanks Sunray, no we've decided it's too much mess for the minute. Yep for sure nice to understand what's happening with the board and although I have some confidence after many years, I value the house insurance too much!

Future proofing in mind two radials would be best I think, but splitting it is another matter. I'd say keeping the fixed appliances on one circuit is best as you wouldn't want a kettle tripping the boiler! Probably fridge, boiler, dishwasher, internet router, extractor hood, and maybe microwave on one 20A, and then worktop sockets would be on their own 20A. I guess we could pull out the units from under the worktop to access that cabling when the time comes.

 

[Ragnar_AT]

Are you actually in the UK? That‘s definitely not a typical UK consumer unit.

I‘d strongly recommend replacing all the non-matching MCBs, the bus bars don‘t fit and that could definitely cause overheating.

 

[Boilerman2020]

West Midlands! Anything's possible up here We are in about 7 years, never had anything done with it. Probably needs a full going over but hopefully not a replacement!