Thermal fuses or thermal cutoffs are safety devices designed to protect electrical appliances and equipment by detecting heat or temperature. These fuses are temperature-sensitive radial or axial switches, breaking or cutting off the circuit and electric flow. A thermal fuse only reacts to excessive temperatures compared to circuit breakers–responding to excessive currents or voltages. Cutoff fuses come with different temperature ratings ranging from 70°C (158°F) to 240°C (464°F) or higher. These ratings determine the temperature at which the fuse will open the circuit. Additionally, these one-time-use devices find applications in various household heat-generating appliances, industrial equipment, and electronics where temperature control and safety are paramount.
Why Buy a Thermal Fuse? Key Advantages to Users
Thermal fuses are an essential safety feature, preventing fires and other electrical accidents from overheating appliances. They protect valuable equipment, property, and individuals by preventing the appliances from continuing to operate when it gets too hot, which otherwise could lead to a fire or other safety issues. Other benefits of thermal fuses include:
- They are easy to install and cost-effective.
- Simple, compact, reliable, and versatile.
- Fail-safe operation for extended periods.
- Fast response time with high energy efficiency.
Operating Principle of Thermal Fuses
Thermal fuses comprise a heat-sensitive element called a pellet that melts or deforms beyond a specific temperature threshold. These safety devices work based on the principle of thermal expansion. When the temperature in the device or equipment exceeds this preset limit, the pellet reacts by melting or deforming (called burning out or blowing out), interrupting the electrical circuit to break, and cutting off power to the device.
Resettable vs. Non-resettable or Single-Use Thermal Fuses
Thermal fuses come in either resettable or non-resettable forms. A resettable thermal fuse, often called a thermal protector, can return to its normal operating state once it cools down. On the other hand, non-resettable or single-use thermal fuses require replacement because they are no longer functional.
Typical Applications of Thermal Fuses
Thermal fuses are typically installed in equipment or appliances requiring robust protection against heat or temperatures. These devices are critical in heat-producing appliances, including:
- Coffee Makers
- Microwave Ovens
- Toasters
- Hair or Machine Dryers
- Space Heaters
- Electronics
- Automotive
- Fire Alarms
- Battery Packs
- Refrigerators
- Surge Protectors.
