Ferraz Shawmut Fuses
There are two main types of fuses: fast-acting and time-delay. Typically, fast-acting fuses are a single strand of wire or strip of metal. Time-delay fuses have a coiled wire, a thick element wrapped in wire or a spring. Glass fuses are available in fast-blow (fast-acting) or slow-blow (time-delay) with a voltage rating of 250 V or less. Their see-through body allows for visible verification if the fuse wire is intact or melted.
Ferraz Shawmut fast-blow fuses are glass tubes with metal caps at both ends and a thin metal strip inside. When an overcurrent flows through it, the wire strip melts, automatically interrupting the power supply. The fuse must be replaced once it is blown. The fuses are amp-rated, indicating the limit of the current volume that can pass through the circuit without blowing the fuse. Fast-blow fuses are commonly used in consumer electronics and appliances that are very sensitive to any overcurrent situation.
Ferraz Shawmut slow-blow fuses are designed to handle a temporary surge current which exceeds the current rating of the fuse. The slow-blow fuse must receive a sustained, elevated current above its current rating for a period of time before it blows. Slow-blow fuses are ideal for capacitive circuits that need power surges upon power input/output or on/off. Devices that use these types of circuits include motors and fluorescent lights.