Mechanical temperature protection switch is a kind of overheat protector without power supply, only two pins, can be used in series in the load circuit, low cost, wide application.
The reliability and performance of this protector to make the protector installed in the motor test, the general requirements of the thermal protector and the motor structure and function installed in one to form a thermal dynamic system, the motor as a heater affects the heating and cooling rate of the protector. The contact is designed by two different metal discs, in use, only need to series the protector in the loop, the shell close to the temperature point can be. The two kinds of metal disc expansion coefficient is different at a certain temperature will occur deformation, so that the contact is disconnected, with the decrease of temperature, and will automatically reset. Thus, the function of high temperature jump and low temperature reset is realized.
It is widely used in household appliances, industrial equipment and health care products. It plays a role of afterheat protection. In case of thermostat failure and other overtemperature overheating, the hot fuse cuts off the circuit to protect the circuit from harmful overheating.
Advantages and Disadvantages
The advantages of this temperature protector are cheap, no power supply, easy to use directly in series in the loop. But the disadvantages are also very obvious, the upper limit temperature and lower limit temperature can not be set, and before the factory has been determined, only from the manufacturer’s specifications to choose their own UT, ST temperature.
Functional Characteristics
When using thermal protectors, it is necessary to determine whether the thermal protectors are self-restoring or non-self-restoring. Generally speaking, self-restoring thermal protectors can be used unless the accidental restart of the motor may lead to danger or injury to the user. Examples of applications requiring the use of non-self-replicating protectors are: fuel motor, waste processor, conveyor belt, etc. Application examples that require the use of self-restoring heat protectors are refrigerators, electric washing machines, electric clothes dryers, fans, pumps, etc.
Installation Precautions
1. When the lead is used, it should be bent from parts more than 6 mm away from the root; When bending, do not damage the root and the lead. Do not forcibly pull, press or twist the lead.
2. When the hot fuse is fixed by screw, riveted or terminal, it should be able to prevent mechanical creep and bad contact phenomenon.
3. The connecting parts should be able to work reliably within the working range of electrical products without displacement due to vibration and impact.
4. In lead welding operation, the heating humidity should be limited to the minimum, pay attention to the addition of high temperature on the hot fuse; Do not forcibly pull, press or twist the hot fuse and wire; After welding, it should be cooled for more than 30 seconds immediately.
5. The thermal fuse can only be used under the specified rated voltage, current and specified temperature, especially the maximum continuous temperature that the thermal fuse can withstand. Note: Nominal current, length of lead and temperature can be designed according to customer’s requirements.
Post time: Apr-12-2023