Fuses

What are Fuses?

Fuses have a thick metal strip through which current passes into a circuit. If too much current starts to flow, the metal melts and cuts off the current. Fuses may be one of several types:

• Plug and Type S fuses have a metal strip (visible through a window) that melts when there's an overload.
• Time-delay fuses have a spring-loaded strip that allows temporary overloads.
• Cartridge fuses show no sign of overload. They must be tested to reveal whether they've blown.

Fuse Safety Tips

• When a fuse blows, always replace it with one of the same type and amperage rating. Never replace it with one rated higher.
• When you need to change a blown fuse, shut off all power before touching the fuse and be sure you're standing on dry ground.