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Overloaded fused spur, opinion please

I was an industrial electrician and have now come across a domestic wiring issue where nothing appeared wrong with the installation.  Those with more experience will have probably have come across this many times.


The kitchen is supplied by a 2.5mm T&E ring fed from a B32 circuit breaker.  On this ring there is a 13A fused switched spur above the worktop feeding a double socket underneath via 2.5 T&E.  There is a washing machine and a dishwasher plugged into this double socket.  Every so often, I assume when both appliances are heating at the same time, the 13A fuse in the spur blows.  The cable supplying this double socket is in the wall so the current-carrying capacity appears to be 18.5A so this was probably being overloaded as well.


I understand that in the regs diversity covers some aspects of this situation, but this specific situation must occur often surely?  The switched spur gives the ability to switch off the appliance easily without having to pull it out in order to reach the switch, so is surely desirable?


In this case I have installed a second switched fused spur feeding a single socket and converted the other to a single.


Is this a common problem in kitchens?
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  • It's also worth bearing in mind that some appliance motors (such as tumble dryers, but perhaps also other appliances motors that have no carbon brushes) can be damaged over time by this arrangement, because of the increased slip in the motor from the additional fuse resistance.


    Whilst double socket-outlets used to be rated at 20 A, for many many years now, double socket-outlets to BS 1363-2 are rated at 13 A max for the entire accessory, that is, both socket-outlets. I understand it could be argued that the type testing at 20 A shows temperature rise shouldn't be an issue, note that this is carried out on a brand new device, conditioned as per the standard, and is for a limited time only - so is not indicative of long-term overloading over the product's life.
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  • It's also worth bearing in mind that some appliance motors (such as tumble dryers, but perhaps also other appliances motors that have no carbon brushes) can be damaged over time by this arrangement, because of the increased slip in the motor from the additional fuse resistance.


    Whilst double socket-outlets used to be rated at 20 A, for many many years now, double socket-outlets to BS 1363-2 are rated at 13 A max for the entire accessory, that is, both socket-outlets. I understand it could be argued that the type testing at 20 A shows temperature rise shouldn't be an issue, note that this is carried out on a brand new device, conditioned as per the standard, and is for a limited time only - so is not indicative of long-term overloading over the product's life.
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