LPJ-9SPI

LPJ-9SPI is a class of specialty fuse designed by Littelfuse. It is designed for use in Class I, Division 2 hazardous (classified) locations in applications requiring branch circuit protection. Also, LPJ-9SPI fuses are UL listed as supplemental protection for larger branch-circuit cables in the many hazardous (classified) areas.

LPJ-9SPI fuses are type J integral molded body time-delay fuses. A molded body is a single-piece unit that, in this case, includes the fuse body, contact, terminals and housing. Integrated molded-body construction means there are no separate components to assemble and worries about proper assembly and contacts to ensure good performance. The integral molded-body design also contributes to the fuse%u2019s superior vibration and shock resistance.

LPJ-9SPI fuses are a one-time fuse, meaning they are intended to be used only once and not to be reset after a fault has occurred. They are designed for use in a wide range of demanding industrial applications, such as paint booth and dip tank circuits, electrical motor starters, air compressor lines and throughout the petrochemical industry.

Time-delay fuse operation requires that the fuse develop a high degree of heat before it opens the circuit. This function results from the current flowing through the fuse%u2019s elements and wires. The LPJ-9SPI fuse has two elements: a copper wire and a spring-loaded piece of silver. During normal operation, the high-rolling current passes through these two elements, causing them to heat up. As the current increases and the elements heat up even further, the silver in the contacts springs away, creating an open circuit.

Each element of an LPJ-9SPI fuse has different characteristics. The copper element is the primary element that provides the time-delay function. The silver element increases melting speed when it reaches a predetermined temperature, eliminating the need for an excess current release or thermal cut-off device.

LPJ-9SPI fuses have many advantages over other types of protective devices. The fuse is designed to prevent branch-circuit overloads from damaging large motors, cables and other components, protecting both personnel and equipment. The integral molded-body construction means that no separate component needs to be assembled to ensure good performance. The built-in time-delay feature allows high inrush currents to pass without tripping the fuse, while at the same time slowing short circuit currents. Finally, the LPJ-9SPI fuse provides reliability and long life, meaning reduced maintenance and less downtime.

In conclusion, LPJ-9SPI fuses provide an important service for the electrical industry, providing circuit protection in hazardous locations while resisting shock and vibration. Their integral molded-body construction and built-in time-delay feature ensure reliability and long life. Their advantages over other types of protective devices make them an ideal choice for a variety of industrial applications.