The Thermal Cutoff Product Division develops and produces thermal protection devices designed to protect electrical equipment from catching fire by sensing overheating, and cutting off the electrical circuit immediately.
NEC SCHOTT SEFUSE® is a trusted brand of thermal links that meet numerous international industrial safety standards. These “one-shot” components provide excellent reliability and performance and is widely used in a wide range of consumer electronics and appliances.
The NEC SCHOTT SEFUSE® SF type is a thermal link based on a one-shot operation principle and prevents electrical appliances from catching fire due to overheating. It uses an organic thermo-sensitive material inside a metal case and is able to operate in electric circuits with large currents.
The SF type contains a sliding contact, two springs and a thermal pellet inside a metal case. Under normal temperatures, the sliding contact touches the top of the lead. The current flows through the sliding contact and the metal case to the other lead and the electrical circuit is closed. When the ambient temperature reaches a critical point, the thermal pellet melts and the springs move the sliding contact away, resulting in an interruption of the electrical flow.
The NEC SCHOTT SEFUSE® SM type is a thermal link designed to protect electrical home appliances and industrial electrical equipment from catching fire. It contains a fusible alloy inside an insulated case which interrupts the electrical circuit by melting when ambient temperatures reaches abnormal levels.
The device is integrated into the electrical circuit of the appliance. Two leads are connected in the device by a fusible alloy, which is coated with a special flux. Under normal conditions, the current flows directly from one lead to the other through the fusible alloy. In case the ambient temperature should reach a critical point, the fusible alloy will melt and then condense into a drop around the end of each lead caused by surface tension and the special coating. As a result, the electric current is interrupted immediately.