User Manual of EM760 High-Performance Inverter 8.2.4 Too long deceleration time of motor ● When energy consumption braking is valid: ■ The resistance ofthe braking resistor is too high, and the energy consumption braking power is too low, which extends the deceleration time. ■ The set value of braking rate (F15.32) is too small, which extends the deceleration time. Increase the set value ofbraking rate. ■ The set deceleration time is too long. Check the deceleration time code. ● When the stall protection is valid:
■ When the overvoltagestall protection is enabled, and the DC bus voltage exceeds the voltage of overvoltage stall (F07.07), the output frequency will remains unchanged; and when the DC bus voltage is lower than F07.07, the output frequency will continue to drop, which extends the deceleration time. ■ The set deceleration time is too long. Check the deceleration time code. 8.2.5 Electromagnetic interference and RF interference ● Since the inverter works in the high-frequency switching status, electromagnetic interference and RF interference will be generate to the control device. The following measures can betaken. ■ Reduce the carrier frequency (F00.23) of the inverter.
■ Install a noise filter on the input side ofthe inverter. ■ Install a noise filter on the output side ofthe inverter. ■ Install a metal tube outside the cables. Install the inverter in a metal casing. ■ Make the inverter and motor grounded reliably. ■ Connect the main circuit and control circuit separately. Use the shielded cables in the control circuit, and connect them according to the wiring method in Chapter 3. 8.2.6 Action of leakage circuit breaker ● When the inverter is running, the leakage circuit breaker works. Since the inverter outputs high-frequency PWM signals, a high-frequency leakage current will be generated.
Please use the dedicated leakage circuit breaker with the current sensitivity above 30 mA. If an ordinary leakage circuit breaker is used, use a leakage circuit breaker with the current sensitivity above 200 mA and action time of more than 0.1 s. 8.2.7 mechanical vibration ● The inherent frequency of the mechanical system resonates with the carrier frequency of the inverter. The motor is not faulty, but the mechanical system produces sharp resonant sounds. This is caused by the resonation between the inherent frequency of the mechanical system and carrier frequency of the inverter. Please adjust the carrier frequency (F00.23) to avoid resonation.
● The inherent frequency of the mechanical system resonates with the output frequency of the inverter. Resonation between the inherent frequency of the mechanical system and output frequency of the inverter will lead to mechanical noise. Please use the vibration suppression function (F05.13), or install the anti-vibration rubber or take other anti-vibration measures on the motor base. 224