5x20mm Time Delay Slow Blow Ceramic Fuse 300VAC 300VDC 500mA to 20A for Inrush Current Protection

This series of 5×20mm time-delay (slow-blow) ceramic cartridge fuses is specifically engineered to provide reliable overcurrent protection in circuits subject to frequent or high-magnitude inrush currents. Unlike fast-acting fuses, these slow-blow devices are designed to withstand momentary surge pulses—such as capacitor charging currents, transformer inrush, and motor startup spikes—without nuisance tripping, while still delivering rapid and safe interruption of sustained overloads and short-circuit faults. With a wide current range from 500mA to 20A and dual 300V AC/DC ratings, these compact ceramic fuses offer an ideal protection solution for power supplies, industrial electronics, and consumer appliances where transient tolerance is critical.
Specifications of 5x20mm Time Delay Ceramic Fuse

Product Name: Ceramic Fuse
Rated Current: 500mA-20A
Rated Voltage: 300V AC/DC
Main Material: Ceramic
Ends Material: Brass
Breaking Capacity: 3000A/300V AC/DC (500mA ~ 10A), 300A/300V AC/DC (12A ~ 20A)
Application: For industrial power

Dimension of 5x20mm Time Delay Ceramic Fuse






Features of 5x20mm Time Delay Ceramic Fuse


•Time-Delay / Slow-Blow Characteristic: Specifically calibrated to ride through harmless inrush current pulses, eliminating false tripping and reducing system downtime while maintaining precise protection against dangerous prolonged overcurrents.

•Wide Current Range: Available from 500mA up to 20A, providing flexible design options for low- to medium-power AC and DC circuits.

•Dual AC/DC Voltage Rating: Rated at 300V AC and 300V DC, enabling versatile deployment across both mains-powered and battery-backed systems without derating.

•Superior Inrush Withstand Capability: Engineered to handle high peak surge currents typical of switch-mode power supplies, capacitive loads, and inductive circuits, ensuring operational reliability during startup sequences.

•High Interrupting Capacity: Safely clears severe fault currents with robust arc-quenching performance, protecting equipment and personnel under short-circuit conditions.

•Premium Ceramic Construction: High-grade ceramic tube provides excellent dielectric strength, superior arc extinction, and outstanding resistance to thermal cycling, mechanical vibration, and moisture—outperforming glass fuses in demanding environments.

•Compact 5×20mm Standard Package: Industry-standard dimensions ensure direct compatibility with existing fuse holders, clips, and PCB-mount assemblies, simplifying both new designs and field replacements.

•Stable Time-Current Characteristics: Maintains consistent performance across a wide operating temperature range, delivering dependable protection in varied environmental conditions.

•RoHS Compliant: Manufactured with environmentally friendly materials in accordance with international standards.


Applications of 5x20mm Time Delay Ceramic Fuse


•Power Supplies: Switch-mode power supplies (SMPS), AC-DC converters, and DC-DC modules with high inrush currents at startup

•Industrial Electronics: Control panels, programmable logic controllers (PLCs), and automation equipment

•Consumer Appliances: Air conditioners, refrigerators, washing machines, and other motor-driven appliances

•Lighting Systems: LED drivers, electronic ballasts, and fluorescent lighting fixtures with capacitive input filters

•Uninterruptible Power Supplies (UPS): Input and output protection for backup power systems

•Battery Chargers: Primary side protection where capacitor banks draw high startup currents

•HVAC Equipment: Compressor and fan motor protection in heating, ventilation, and air conditioning systems

•Telecommunications: Power distribution units and rectifier modules

•Test and Measurement Instruments: Equipment requiring stable protection with transient immunity

•Renewable Energy: Solar inverters and wind turbine auxiliary power circuits

Contact Details:

Andy Wu

Email: andy@tianrui-fuse.com.cn

Tel/Whatsapp: +86 13532772961

Wechat: HFeng0805

QQ: 969828363