MCB's Protecting Spur

[Spark123]

A double socket is not rated at 26A.

I can't comment on other manufacturers but MK twin sockets are rated at 13A per outlet, 26A total.

http://www.mkelectric.co.uk/PDF/technical/LOGIC_PLUS_tech.pdf[/QUOTE]

Not sure if they mean simultaneously though, this was posted a while ago re MK double sockets: //www.diynot.com/forums/viewtopic.php?p=42047#42047

 

[GaryMo]

I took it to mean simultaneously due to the wording below for 3 gangs sockets - 13A total.
If there was a total limit on the 2 gang sockets they would have said so, not just 13A per outlet.

http://www.mkelectric.co.uk/PDF/technical/LOGIC_PLUS_tech.pdf

 

[OBB7]

I reckon both appliances running together will draw about 15.5-16A, and so shouldn't trip the MCB even taking some peak currents at start-up into account. 16A MCB should provide sufficient protection for the 2.5mm spur - with some safety margin.

Have you read the rating plates on the washing machine and the tumble drier?

Thanks Spark123.

Tumble dryer is rated at 2300W which I guess it will draw constantly on the full-heat setting, whilst washing machine is rated at just under 1000W based on most demanding cycle (95 degC wash with 6Kg load).

I think this should mean that both appliances can run together without likelihood of tripping 16A MCB, which should give enough protection for 4M of 2.5mm in a dry-lined wall.

What do you think?

 

[ban-all-sheds]

The WM will be 1000W for any temperature (other than cold), but for less time.

But 3.3kW is only 13-14A.

 

[Pensdown]

Hi - I have an attached garage with a double socket fed by a spur in single 2.5mm. Spur is from a junction box in the ring-main (about 4 meters away in the hallway of the house).

I've asked my electrician to make the system safe for a tumble dryer and washing machine to be used in the garage.

Based on the information that you have supplied about your existing circuit and your appliances, your existing double socket is already suitable for a tumble dryer and washing machine, or any other two appliances that are fitted with 13amp plugs.

You don't need the 16amp MCB and you don't need to do anything other than plug your appliances in.

 

[OBB7]

Thanks Pensdown/Ban.

Maybe I'm being over cautious, but I'd rather have some protection on the spur cable. Worst case I guess would be that both appliances develop a fault and draw more than 13A each, potentially overloading the 2.5mm spur cable. I'm then relying on the 13A cartridge fuses to blow. If both appliances were pulling say 15A each, it could take some time before the 13A fuses blew, and spur cable could be at risk.

MCB and Box tinstallation not too expensive, so I'm happy to go for belt and braces.


Ban - Miele quote 1.99Kwh over 129mins for the 95 degC 6Kg cycle. Am I OK using Kwh to watts conversion to get power rating of 925W, or is this an average that could be understated?

More typical wash (40 degC 6Kg for 115 mins is given as just 0.65Kwh

 

[ban-all-sheds]

Ban - Miele quote 1.99Kwh over 129mins for the 95 degC 6Kg cycle. Am I OK using Kwh to watts conversion to get power rating of 925W, or is this an average that could be understated?

Let me answer that by asking you an analogous question.

If you drove your Ferrari down the motorway at 180mph for 30 minutes, then stopped at the services for 2 hours, and then drove it at 180mph for another 30 minutes, would the magistrates let you off because your average speed was only 60mph?

These integral kWh figures are an absolute nonsense - I have a 10.5kW shower, if I use it for 20 minutes per day it will consume 3.5kWh every 24 hours, but I can't therefore size the cable for a load of 634mA...

 

[OBB7]

Thanks Ban, that's what I feared. I'll have to double check power rating of my WM, but I think that 1000-1200W is pretty typical. Miele user manual doesn't provide specs. so I'll have to check-out the plate on the back of the machine.

 

[ban-all-sheds]

It might be inside the door - they are on my Mieles....

 

[sparkyspike]

Thanks Pensdown/Ban.

Maybe I'm being over cautious, but I'd rather have some protection on the spur cable.
MCB and Box tinstallation not too expensive, so I'm happy to go for belt and braces.

Why not fit 10A fuses to your plugtops and keep the spur as it is??

 

[Spark123]

Thanks Ban, that's what I feared. I'll have to double check power rating of my WM, but I think that 1000-1200W is pretty typical. Miele user manual doesn't provide specs. so I'll have to check-out the plate on the back of the machine.

I think you need to double check it yes, as 1000-1200w doesn't seem very big to me as WMs normally have an inbuild water heater.