
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.
Products
Fuses are safety devices that are intended to provide protection to both equipment and people in the event of a power surge or an overcurrent situation. A fuse can provide this protection by using a small piece of wire that is sacrificial, and is intended to burn up when too much current is passed through it. When this happens, the fuse eliminates the flow of electricity in that circuit until it is replaced. The size and type of wire that is used in the fuse will dictate how much current can pass through that individual fuse. So the main thing to remember is, when a fuse blows, it must be replaced and cannot be reused.
Circuit breakers are intended to be reused after they are “tripped” during a power surge or an overcurrent situation. Much like fuses, circuit breakers are designed to trip at a certain current level. This is intended to protect both equipment and anyone in the area of that particular circuit. Circuit breakers can be found in just about any variation from single phase, low current applications to three phase, and high current applications.
As a general rule: fuses are more simplistic and reliable. They cost less initially and are better suited for individual circuit protection. However, they can create more cost over time with each use and may create hazards due to the exposed connection points. Whereas circuit breakers offer better branch circuit protection and do not need to be replaced after each use. They are more expensive initially and, because of their complexity, are more prone to failure over time.