• It is suitable for protecting circuit boards.
• Flameproof construction in a ceramic case, resistant to humidity and insulation.
• In high resistance value, the winding cores will be replaced by power film cores.
• Excellent anti-surge characteristics and accurate fusibility.

The SQF series thermal fuse cement resistor is a wire wound resistor designed for circuit protection. It uses a flameproof ceramic case and combines wire winding construction with a thermal fuse function to provide protection when the circuit reaches specified overload or thermal conditions.

For industrial electronics and circuit board applications that require both resistance and thermal fuse protection, the SQF series can be used as a flameproof fusible resistor. The product specifications also identify anti-surge characteristics and accurate fusibility, together with defined insulation and environmental test conditions.

The SQF series can be evaluated through defined electrical and environmental test conditions rather than unsupported performance claims.

• ≥1,000MΩ @ DC500V insulation resistance provides a quantitative reference for insulation performance.
• AC 1000V / 1 minute dielectric withstand provides a defined dielectric strength test condition.
• 10× rated wattage / 5 seconds short-time overload provides a quantitative overload test condition.
• 40°C / 95% RH / 500 hours moisture-proof load life provides an environmental endurance reference under high humidity.

These test conditions are specified under the product's electrical, mechanical and environmental characteristics.

The SQF series is designed for circuit board protection. It can be positioned in a protection branch where both resistance and thermal fuse functionality are required, providing a combined resistor and thermal protection function. The product documentation specifically identifies circuit board protection as an application.

In industrial electronic equipment, the SQF series can function as an overcurrent protection resistor in circuit sections requiring resistance and thermal protection. Rated current options of 3A, 5A and 10A, together with rated functioning temperatures of 132°C, 145°C and 185°C, provide different configuration options for circuit design.

In power and control circuits requiring circuit protection, the wire wound thermal fuse resistor combines resistance with thermal fuse functionality. Its short-time overload test is specified at 10 times rated wattage for 5 seconds, providing a measurable reference for component selection.

The SQF series is specified with excellent anti-surge characteristics and accurate fusibility. It can therefore be considered for circuit protection positions where these characteristics are required. For European B2B electronic component sourcing, the product can be positioned as a fusible wire wound resistor for circuit protection applications.