LA30QS4504

LA30QS4504 Application Field and Working Principle

The LA30QS4504 electrical specialty fuse is a low voltage and medium breaking capacity fuse. It is mainly used in low voltage switchgear, AC 50/60Hz, single phase AC 230/400V or 200/415V, three phase AC at 500V or so or DC 500V, rated current up to 450A, breaking capacity up to 70KA.

Application Field

LA30QS4504，which has current ratings from 63A to 450A, is widely used in AC38V, AC440V, DC500V, single and three-phase industrial and commercial applications for motor load, capacitor, lighting, backup lighting and other load control. Also, LA30QS4504 electrical fuse is suitable for mobile power supply, circuit breaker, switchgear, electrical cabinets, power distributions and other electrical systems.

Working Principle

The LA30QS4504 fuse is an over current protection device that will disconnect a circuit when it is overloaded or short circuited. It will either break the electrical connection when a certain predetermined amount of current flow is exceeded, or will break the electrical connection if the temperature of the fuse rises beyond its design value. The fuse has a thermal element which will melt, interrupting the circuit when the load exceeds the rated current for the size of the specific fuse.

During the overcurrent operation, the parts in thermally sensitive area begin to heat up, reducing the contact resistance between the fuse contacts and at some point causing them to separate. When the current set point is lower than the melting point, the contact temperature will stabilize and allow the current to flow. When the set point is higher, the thermal element will melt and the contact resistance will be increased, preventing further current flow. Breaking the electric connection before it can cause damage to the equipment being protected.

The advantages of the LA30QS4504 electrical fuse include stable breaking capacity and high safety performance, high breaking capacity, unique arc extinguishing structure, quick response to overcurrent, easy installation and maintenance, rapid breaking capacity and high temperature resistance.