What is the purpose of a "13 amp fuse" in a plug?

Question

Why does my plug have a 13 amp fuse in it?

Answer 1

It's purpose is to limit the amount of 'current' to a maximum of 13 amperes, beyond which, the fuse will fail.  This way, it prevents overloading the circuit, or the equipment.

It is quite amazing though, how many people have the wrong fuse installed!  Always check the required fuse (in the equipment's handbook) and never use a 'stronger' fuse than recommended.

Commonly, people will put in a 13 amp fuse just because it's a 13 amp plug!  The idea is to use a fuse rated to suit the equipment, and thereby protect it from overload damage.  

Table lamps and radios typically use a 3 amp fuse.  HiFi and TV equipment, typically, 5 amp. Kettle, microwave oven and toaster, typically, 13 amp.

Different rated fuses fail at different current loadings, and in a fault condition, a 13 amp fuse in circuit with a device requiring say, a 3 amp fuse, would most likely result in the device being severely damaged or even cause a fire because the internal components of the device will fail at a lower current than would the fuse.  It is even possible for the mains lead (flex) to overload and heat up to the point where it will ignite, and could actually cause a house fire, all for the sake of using the correct fuse.  It really is that important, and it is for this reason that British "BS 1363" standard square pin plugs are considered to be the safest in the world, and are employed in many countries all over the world.

Answer 2

the fuse is there to protect you and the appliance if a fault develops different appliances have different fuse ratings .not all need a 13amp so make sure the appliance is fused correctly

Answer 3

A 13 amp fuse should only be fitted in appliances that draw heavy current. In most households, the majority of plugs will have the wrong size fuse fitted.

Answer 4

Anything over that will blow it saving what ever thing you're using from getting burnt out.

Answer 5

A fuse is the weakest link in an electrical circuit.  So, if a fault develops in an appliance, the fuse blows in preference to the appliance catching fire.

Answer 6

It's used so that the fuse blows before the appliance blows. There are also 5 amp fuses.

I believe that only the UK and Ireland use this system.

Answer 7

They use them in things like Christmas lights that are wired in a series to save the structure from a fire when it finally burns out, it's not a matter of if it's a matter of when with that sort of plug configuration.