- Stock: 34
- Model: Fusible125ºC
One-shot flat thermal fuse designed to open the circuit when its body reaches approximately 125°C. It includes two insulated leads and a mounting hole to position it close to the component or surface being monitored.
Its marking indicates maximum ratings of 250 V and 15 A. It is an overtemperature safety device and must not be confused with a conventional overcurrent fuse.
Main features
- Type: thermal fuse or thermal cutoff.
- Rated operating temperature: 125°C.
- Marked maximum voltage: 250 V.
- Marked maximum current: 15 A.
- Flat body with mounting hole.
- Two insulated leads.
- Normally closed before operation.
- One-shot, non-resettable device.
How it works
During normal operation, the fuse allows current to flow. If its body reaches the operating temperature, its internal contact permanently opens and interrupts the circuit.
Once operated, the fuse does not close again after cooling. It must be replaced, and the cause of overheating must be identified before the equipment is returned to service.
Typical applications
- Additional thermal protection in electrical equipment.
- Monitoring heaters and hot surfaces.
- Power supplies, transformers and motors.
- Domestic appliances and machinery.
- 3D printing and automation projects requiring independent thermal protection.
Selection and compatibility
For replacement use, the required operating temperature, current, voltage, package, mounting method and electrical characteristics must all match. It must not be selected solely because it physically fits or has the same temperature marking.
The 250 V and 15 A markings are declared maximum ratings. They do not mean that every load operating below both values is automatically compatible. Current type, connected load, interrupting capacity and thermal mounting conditions must also be considered.
Installation
The body must be thermally coupled to the surface being protected and provided with suitable electrical insulation. Its position is important: if it is too far from the heat source, it may react too late; if the normal operating temperature approaches 125°C, it may open during intended operation.
Heat applied during connection can damage or prematurely operate the fuse. Use an appropriate connection method, minimise heat transfer towards its body and follow the equipment's installation procedure.
When installed in equipment connected to mains voltage, work must be carried out by a qualified person while preserving the original insulation, clearances, protective earth and other safety systems.
Safety warnings
- Not resettable or reusable.
- Never bridge it after operation.
- It does not replace an overcurrent fuse.
- It does not replace a control thermostat.
- It does not replace protective earth or other electrical protection.
- In a 3D printer, it does not replace the temperature sensor or firmware thermal-runaway protection.
Package contents
- 1 × 125°C, 250 V, 15 A flat thermal fuse.
