The supplier of frequency converter braking unit reminds you that one of the main reasons why frequency converters play an increasingly important role in industrial production is that they rely on the internal IGBT to adjust the voltage and frequency of the output power supply, providing the required power supply voltage according to the actual needs of the motor, thereby achieving energy-saving and speed regulation. What are the methods and measures for protecting motors with frequency converters?
1. The output of the overvoltage protection frequency converter has a voltage detection function. The frequency converter can automatically adjust the output voltage to prevent the motor from withstanding overvoltage and operate within the set voltage range.
2. Under voltage protection: When the voltage of the motor is lower than 90% of the normal voltage (some are set to 85%), the frequency converter protection stops.
3. Overcurrent protection: When the current of the motor exceeds 150%/3 seconds of the rated value, or 200%/10 microseconds of the rated current, the frequency converter stops to protect the motor.
4. Phase loss protection monitors the output voltage. When there is a phase loss in the output, the frequency converter alarms and immediately stops to protect the motor.
5. The inverter with reverse phase protection can be set to only rotate the motor in one direction, and the rotation direction cannot be set. Unless the user changes the phase sequence of the wiring of motors A, B, and C, there is no possibility of reverse phase.
6. Overload protection: The frequency converter monitors the motor current. When the motor current exceeds 120% of the set rated current for 1 minute, the frequency converter stops to protect the motor.
7. The grounding protection frequency converter is equipped with a dedicated grounding protection circuit, which is generally composed of grounding protection transformers and relays. When one or two phases are grounded, the frequency converter will immediately shut down. Of course, if requested by the user, we can also design to immediately protect the shutdown after grounding.
8. Short circuit protection: After the output of the frequency converter is short circuited, it will inevitably cause overcurrent. Within 10 microseconds, the frequency converter will stop to protect the motor.
9. The overclocking protection frequency converter has maximum and minimum frequency limit functions, which limit the output frequency to a specified range, thereby achieving the overclocking protection function.
10. Stall protection generally applies to synchronous motors. For asynchronous motors, stall during acceleration is inevitably manifested as overcurrent, and the frequency converter achieves this protection function through overcurrent and overload protection. Stalling during deceleration can be avoided by setting a safe deceleration time during the debugging process.