Oil-cooled Drum Motor. The thermal protection device of the motor in the oil-cooled electric drum is to put a thermistor in the three-phase winding of the motor, a thermistor is put in each phase winding, and three thermistors are connected in series. In the three-phase winding of the motor, as long as the heat generated by the one-phase winding exceeds the specified temperature, the bimetal sheet will play a role in cutting off the power supply, and the motor will stop working immediately. In this way, the thermal protection device provides overload protection. After a period of time, when the motor winding temperature gradually drops to the normal operating temperature, the bimetallic sheet also cools down and returns to the initial state, the circuit is connected, and the motor can work normally again.
Because the motors have different insulation grades, the temperature at which the bimetallic sheet in the thermal protection device of the oil-cooled electric drum starts to operate is also different. Use can be selected according to the need. As already mentioned, thermal protection devices are operated by the thermal effect of electric current. We call the current that the thermal protection device does not operate for a long time the setting current. When the overload current exceeds the setting current, the thermal protection device begins to operate. The speed of action is related to the size of the overload current. When the overload current is 1.2 times of the setting current, the operation time of the bimetallic strip is about 20min. When the overload current is 1.5 times of the setting current, the operation time of the bimetallic strip is only 2min. Of course, in addition to the thermal protection function, the oil-cooled electric drum has many other special functions. When choosing the drum motor, you can choose the equipment installed outside the drum, so that the heat generated by the motor can be timely distributed, will not affect the use of the drum, so as to improve the operation efficiency of the equipment.