About Low Voltage Fuses
Low voltage fuses are key short-circuit and overcurrent protection components for low-voltage power distribution networks and electric drive systems. Ceramic fuses are the most widely used type. When the current exceeds the rated value, the internal fuse element melts by self-heating to cut off the circuit and realize circuit protection. They are widely applied in low-voltage power distribution, control systems and electrical equipment. The industry is now developing towards high conductivity materials, high breaking capacity and modular structure. Shuguang low voltage fuses keep pace with industry trends with excellent performance, making them the preferred choice for low-voltage power distribution.
Structure and Main Technical Parameters of Fuses
1. Fuse Structure
Fuse Element: The core part, available in wire, sheet and mesh shapes. Lead-tin alloy has been eliminated in the industry, and copper and silver are mainstream materials. Shuguang adopts high-purity silver and copper for fuse elements to achieve accurate fusing and quick response.
Fuse Tube: Protective housing for fuse elements, made of high-temperature resistant insulating materials with arc extinguishing function. Premium products are filled with quartz sand for better arc extinction. Shuguang fuse tubes are made of ceramic or bakelite, featuring good insulation, heat resistance and excellent arc suppression effect.
Fuse Base: Used to fix fuse tubes and external connecting wires. Shuguang bases are treated with anti-corrosion process, featuring low contact resistance and suitable for various installation environments.
Core Working Performance
1. Special short-circuit protection device for low-voltage power distribution and electric drive systems, also applicable for slight overcurrent protection.
2. Composed of fuse element, fuse tube and fuse base. Modular design enables easy installation and removal.
3. Connected in series in protected circuits. The current carrying capacity of fuse elements matches the circuit. It blows instantly to break the circuit under short-circuit conditions, fully protecting power lines and electrical equipment.
Fuse Selection Guidelines
Select proper fuses according to working environment, load characteristics and short-circuit current. Shuguang provides complete series of models and specifications. The main selection rules are as follows:
1. Model Selection: Select based on application scenarios. RL1 screw-type fuses fit machine tool electric control systems; sealed tubular fuses such as RM3 and HH3 series are suitable for indoor power distribution.
2. Rated Voltage & Current: Rated voltage shall be no lower than circuit voltage, and rated current shall be no lower than the current of equipped fuse elements. Our products cover 250V, 380V, 500V voltage grades and 15A to 600A current range.
3. Selection of Fuse Element Rated Current
(1) Lighting and electric heating equipment: Fuse current ≈ load rated current
(2) Infrequently started motors: IRN ≥ (1.5~2.5)IN
(3) Multi-motor combined protection: IRN ≥ (1.5~2.5)INx+∑IN
Selection Example: For Y112M-4 machine tool motor (4kW, 380V, 8.8A), choose Shuguang RL1-60/20 fuse matched with 20A dedicated fuse element. It has rated current 60A and rated voltage 500V, perfectly meeting protection demands.
Installation & Operation Instructions
Follow industrial standards and product features:
1. Use intact qualified fuses. All Shuguang products pass strict factory tests with reliable quality.
2. Ensure tight contact between fuse element and clip, clip and base to avoid overheating and accidental blowing.
3. Use original standard fuse elements. Matched Shuguang elements are recommended to ensure stable performance.
4. Cut off power supply completely before replacing fuse elements or tubes. Modular design allows easy replacement.
5. Replace fuse tubes of RM10, RM3 and other series in time when reaching rated breaking capacity.
6. Troubleshoot and eliminate circuit faults before installing new fuse elements after blowing.
7. When used with isolating switches, install fuses at the power incoming end of control switches.
Complying with domestic and international standards and approved by authoritative institutions, Shuguang low voltage fuses are widely used in indoor power distribution, machine tool electric control, lighting systems and other fields, building solid safety protection for stable operation of low-voltage circuits.