testing for a blown fuse

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Fuses come in several different forms but all do the same thing, they are a deliberate weak link in a circuit. Fuses are there to protect a circuit and more importantly to protect people using electricity. A fuse will not stop you being electrocuted but it should blow before it causes a fire in a faulty appliance.

A fuse is simply a piece of wire that is designed to carry a certain amount of current, which is determined by the thickness of the wire in the fuse. A thin fuse wire will fail with just a few Amperes whilst a thick fuse wire could carry a hundred amperes or more.

The main fuse in your home is supplied by the electricity company and is normally rated at 100 Amperes, This fuse is protected by a tamper proof seal to prevent people tampering with it as the supply to this fuse cannot be isolated! Contact with the supply cables would mean almost certain death! Do Not interfere with this fuse. If you suspect the main fuse has blown then call a qualified electrician.

Fuses often blow for no apparent reason and it does not necessarily mean that there is a fault with the appliance.

FUSES IN PLUGS

To check whether a fuse has blown in a plug you are going to need a screwdriver and Multi meter, if you do not have a multi meter do not worry as it is still relatively easy to check. Start by switching the appliance off at the socket and remove the plug from the socket. Remove the screw from the centre of the plug and pull off the cover to expose the fuse.

The fuse can be tested without removing it from the plug but here I have removed it for clarity. You must make sure that it is placed on a non conductive surface to test it. Do not hold it in your hands as this can give a false reading as you are conductive!

Select OHMS on your multi meter and then Hold both of the probes together to test the meter, the reading should be zero.

Now hold the probes on each end of the fuse.

The reading on the multi metre should be zero, if the reading is not zero then the fuse has blown and needs replacing.

If you do not have a multi meter or suitable tester then the only way to test a suspect  fuse is to put it into another appliance that you know is working!