Examining plugs and fuses is just one of the many tasks performed during our testing procedure and is an essential part of electrical safety. A damaged or faulty plug can cause serious problems such as a fire or a risk of electric shock. HT PAT Testing will fully check all appliance plugs and fuses and this page describes the types of problems we will be looking for.
A full check that the plug has no visible signs of cracks or external damage.
Assessment that the plug is suitable for the appliance, a tough plug marked BS 1363A may be necessary if the plug is in harsh conditions such as a vacuum cleaner, extension leads or gardening equipment.
Signs of any overheating. This can be caused by a fault in the plug such as a loose connection or a loose socket connection.
We will check that the flex is properly secured by the plug grip. Appliance flex should be held securely so there is no chance of a loose connection occurring such as the earth.
If the plug is a molded type then the cable grip will be firmly tested to check for any damage.
The plug will be checked for polarity, the brown core has to be connected to the phase or L (live) pin, the blue core has to connected to the N (neutral) pin and the green and yellow has to be connected to the E (earth) pin. Old wiring is different live is red, neutral is black and earth is green.
A check that all cable core terminations are tight and secure to ensure there is a reliable connection.
A check for loose strands and too much cable core taken off.
The plug label should be removed to prevent any overheating or bad connection to the socket.
All standard 13a plugs that are now sold are required by law to confirm to BS 1363, which requires pins to be sleeved.
Check that the fuse rating is correct, the recommendations provided by the manufacturer should be followed, most appliances up to 700w should have a 3A fuse fitted (red) and appliances over 700w should have a 13A fuse fitted (brown). Non rewireable plugs have the appropriate fuse rating on them.
Other fuse sizes do exist such as 1A and 2A which are used for low amp appliances or 5A which is often used for it equipment, 10A and 16A.
The fuse in a plug is not fitted to protect the appliance, although in practice it often does this. The main purpose of the fuse is to protect the flex against any faults and can allow for a reduced size (csa) cable, this is useful for appliances such as christmas tree lights.
Foil or nails should never be used as a replacement for a BS standard fuse.
All fuses should be BS 1362 standards, an asta mark shows that it has been approved for safety. The fuse should be securely gripped and should not show any signs of overheating.