I live in a house that is only 11 years old, so I consider the wiring to be fairly modern. The fuse box is full of MCBs with a central RCD controlling half of the board.
We have a utility which contains a washing machine and tumble dryer, both are Bosch and both are less than a year old. The two appliances are plugged into a surface mounted double socket in the cupboard. The socket is fed from a 13A switched spur unit on the wall above the cupboard. There is a sink unit in relatively close proximity to the switched spur. All of the electrical installation was done by the original builder.
When we first moved in we had a washing machine and tumble dryer in the same configuration, but when these expired last year we replaced them with the Bosch's. We never had a problem until recently when the 13A fuse blew in the spur. I replaced the fuse, which has lasted about 4 weeks until it blew again yesterday. My wife also reports that the spur was 'warm'. Alarm bells are ringing. The new appliances are supposed to be more energy efficient than the old ones...
It seems that the two appliances running together are overloading the spur unit, but I don't understand why we had 10 years of faultless service with the older appliances.
Where do I go from here? I'm thinking I should upgrade the spur unit to a 20A DP switch as both appliances have their own 13A fuse in the plug. Will the existing 2.5mm flat twin & earth be sufficient in this case?
What are the regulations governing appliances fed from the same spur, and does the spur have to be fused? Am I going to have to run each appliance separately to prevent overloads, or could I have a faulty appliance?
One final thing, I suspect the spur unit to be faulty. I switched this off when there was no load on it and the main RCD tripped as a result. Could this be the reason its own fuse blew, or could the fault have developed from being overloaded at times?
have a look in the appliance spec and see if you can see any info on the power useage of these, it may also be stamped on the appliance somwhere. then you (or someone here) cancalculate the load. that will give some indication as to your options. also the instructions will tell you what sort of supply you can have, it may be the internals of the appliances are not suitable for 20amp protection and you will be turning the internal cabling of the appliance into your fuse!
[quote="moggy1968"]have a look in the appliance spec and see if you can see any info on the power useage of these, it may also be stamped on the appliance somwhere. then you (or someone here) cancalculate the load. that will give some indication as to your options. also the instructions will tell you what sort of supply you can have, it may be the internals of the appliances are not suitable for 20amp protection and you will be turning the internal cabling of the appliance into your fuse![/quote]
I would hope that the 13A fuse in the appliance plug would go first! But having said that, I think the way forward is to install a second fused spur feeding a separate socket so each appliance is on its own spur.
Hi FenderBender, wil try and pick some issue out of this. If your fused connection unit is as you have stated it's doing what it supposed to do by breaking when a fault occurs. Does it only happen when both appliances are running or does it happen when a single appliance is running only, is one of these causing the fault?
Have a look at terminals within FCU and socket-outlet at appliances, make sure they are not loose and correctly terminated with no conductor wire showing. Use safe isolation, make sure circuit is dead before you look at it.
Last edited by kbrownie on Thu Feb 26, 2009 9:29 pm, edited 1 time in total.
sorry, I thought when you were talking about 20 amp unit you were going to hard wire them rather than using plugs, my mistake. however, the idea of using a fused spur is to stop the spur being overloaded, if it keeps blowing the answer is not to, in effect, increase the size of the fuse by fitting a 20 amp spur but to rethink the distribution of the load or, as KB says, to look for other possible reasons for it blowing.
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