Overload protection: When the motor runs over its rated current for a long time under an overload fault, it will cause the motor to overheat, reduce insulation or even burn. At this time, the integrated motor protector will calculate the thermal capacity of the motor based on the heating characteristics of the motor and simulate the heating characteristics of the motor to protect the motor. This protection mode is called overload protection.
Underload protection: When the load carried by the motor is a pump load, the motor running without load or under load will cause harm. The underload protection function provided by the protector is that when the percentage of the average current of the three phases to the rated current is lower than the set value, the protector should act within the action (delay) set time or alarm within the alarm time. This protection function is mainly used to protect applications on pump equipment.
Overheating protection: The overheating protection uses mathematical methods to establish the heating model of the motor, and solves the thermal protection problem of the low-voltage motor in principle. Generally, traditional thermal relays have this protection function.
Phase loss protection: When the three-phase power supply current is unstable due to environmental factors, one phase is disconnected or abnormal, the motor protector will detect the lack of phase of the equipment and act to protect it. This protection behavior It is the lack of phase protection.
Phase sequence protection: A protector with phase sequence protection function. When the voltage phase sequence on the power supply side is consistent with the originally set sequence, the protector will not act; when the motor protector detects that the phase sequence of the motor is connected incorrectly, the motor The protector will react, so that the motor cannot be started.
Undervoltage protection: During the operation of the motor, the operating voltage is too low to cause the motor speed to decrease or even stop running. When the operating voltage of the motor drops to the set under-voltage protection range, the protector will perform protection according to the set requirements, and act within the set time of action (delay), or alarm within the alarm time, so as to avoid Important production processes caused chaos and severely affected production.
Overvoltage protection: Too low working voltage will cause malfunction, and too high is no exception, it will cause motor insulation damage. When the operating voltage of the motor exceeds the set protection voltage, the protector will perform protection according to the set requirements. It will act within the set time of the action (delay) or give an alarm within the alarm time to ensure the motor equipment. Safety.
Grounding and leakage protection: The grounding protection current signal is taken from the vector sum of the internal current transformer, which is used to protect the short circuit protection of the phase wire to the metal outer box of the motor. Moreover, the protector can detect the fault current by adding a leakage current transformer and be used for indirect grounding protection equipment, thereby ensuring the personal safety of the operator and improving the safety of the equipment.
Starting overtime protection: During the starting process of the motor, the protector has protection functions such as open-phase (three-phase unbalance) and grounding/leakage, and the other protection functions cannot protect it. Only after the start is over, all the protection functions (according to the user's actual setting) will be automatically put into protection. The starting overtime protection means that when the starting time of the motor exceeds the starting time actually set by the user, and the current is still greater than 1.1 times the rated current, the comprehensive motor protector will take protection work according to the set requirements, and the action (delay) A stop warning is issued within the set time, so that the motor stops running and the protection equipment fails accordingly.