Plug Fuses

Plug Fuse Graphic Plug fuses are round fuses which screw into a base in the fuse holder to complete the circuit. A plug fuse contains a strip of soft wire or metal. The strip of metal is designed to carry a given amount of electric current, such as 15 amps. If anything happens causing more current to flow in the circuit than the circuit and the fuse are designed to carry, the metal strip melts or "burns out". This opens the circuit, stopping the flow of current and protecting the wiring.

The threads on the base of the common plug or screw type fuse are the same as found on light bulbs. This base and thread size is commonly referred to as an "Edison base", in honor of Thomas Edison who invented the first light bulb. An Edison base fuse is a plug type fuse having this size and type of base. Edison base fuses are discouraged since they allow any size fuse to be placed in the Edison base which makes it easy to "overfuse a circuit" or electrical appliance.