
Littelfuse Fuses

Littelfuse Class L fuses include KLPC series fuses for AC circuits from 601 to 6000 amperes, as well as LDC series fuses for AC and DC circuits available from 601 to 2000 amperes. When facilities have a combination of large AC and DC circuits, standardizing to LDC series for all Class L fuses should be considered. This eliminates the possibility that an AC-only fuse will be used in a DC circuit and reduces inventory.
Littelfuse Class RK5 fuses provide protection for electrical systems that are 600 amps and smaller, and have available short-circuit currents less than 100,000 amperes. The FLSR_ID indicator series fuses provide superior time-delay protection, plus they have the patented indicating window that immediately shows which fuses are blown.
Littelfuse Class RK1 fuses provide time-delay protection where fault currents exceed 100,000 amperes. The LLSRK series reduces short-circuit damage to full-size NEMA and sensitive IEC motor controllers and is capable of providing Type 2 “no damage” protection to NEMA size motor starters. The LLSRK_ID series provides the patented indicating window design.
Littelfuse Class J fuses provide the amount of time-delay necessary for most applications and are substantially smaller than RK5 or RK1 fuses with current-limitation equal to the RK1 fuse. The JTD_ID series fuses provide IEC Type 2 protection to both IEC and NEMA control components and motor controllers.
Littelfuse Class CC fuses are installed in LEC or LEB weatherproof fuse holders in the base of lighting standards and withstand corrosive and wet conditions. Fusing each lighting fixture eliminates the need to test the entire circuit when only one fails.
Littelfuse Class K5 fuses are “one-time” fuses that provide low cost protection for general-purpose feeder and branch circuits when available short-circuit currents are less than 50,000 amperes. They are suitable for use in many residential and smaller commercial and industrial applications.
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.