
Fuses

Fuses are devices placed in series with a circuit to prevent damage from short circuit and overcurrent. A simple fuse consists of a conducting material inside a non combustible case. A certain amount of current is allowed to flow through the fuse. When a short circuit or overcurrent occurs, the heat will melt the conductive material, causing the circuit to open and the power supply to stop. Fuses can be classified into two main categories: AC fuses and DC fuses.
DC Fuses protect a DC circuit from short circuit and overcurrent. When an overcurrent in a DC circuit occurs and melts the metal wire, an electric arc is possible. To counteract this effect, the electrodes of the DC fuses are placed further apart. Thus, DC fuses are larger than AC fuses.
Rewireable fuses (AC) consist of a fuse base and a fuse carrier. When the fuse is blown due to overcurrent, the fuse carrier can be removed from the fuse base, with no risk of electric shock, and the fuse wire can be replaced.
Cartridge fuses (AC) are completely enclosed structures with the fuse links inside the container. There are two types of cartridge fuses: D-type cartridge fuses and Link type cartridge fuses. D-type cartridge fuses keep the cartridge (containing the fuse element) inside a fuse cap. When the fuse cap is inserted into the fuse base, using an adapter ring, and the tip of the cartridge touches the conductor, the circuit is compete. Link type cartridge fuses or high rupturing capacity fuses allow an overcurrent to flow through the fuse for a short, known time period. If the overcurrent is not resolved in the allotted time period, the fuse blows.
Products
Breakers vs Fuses
Fuses
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
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.