What is thermal motor protection?
The thermal motor protection is often used to install in the power transmission between the active and passive side, when the overload fault occurs (torque exceeds the set value), torque limiter will produce separation, so as to effectively protect the driving machinery and load.
The thermal motor protection is designed according to the actual needs of the electrical control industry circuit protection device, using single-chip technology, complete functions, reliable action, strong anti-interference ability, adapt to the bad working environment. Can provide effective protection to electrical system, squirrel cage motor, winding motor overcurrent, short circuit, missing phase, phase unbalance, wrong phase and start process (avoid start overcurrent).
Thermal protection by the current transformer sampling signal, so that each phase of the load current into its proportional voltage signal, the signal and all control signals input to the microprocessor, the microprocessor constantly collect, calculate and store all kinds of signals, and compared with the corresponding conditions, and then output results.
Generally, overload protectors have two protection functions of starting and running. When the air conditioning compressor is started, due to mechanical failure to make the rotor "rolling evil", the current rises rapidly, when the current exceeds the starting current rating, the overload protector switch jumps, cuts off the current, avoiding the burning of the motor starting winding. When the air conditioning compressor is in normal operation, due to external reasons, when the temperature rise is too high or the current is allowed, the protector contact will jump off, cut off the power supply, and avoid the burning of the motor winding.