Inverter repair the fault of case-control roller motor AEG Maxiverter-170/380 inverter has the speed feedback value is greater than the speed setpoint by the observation that: a) there is no such situation in the rolling process, after leaving the steel roller, just happen; b) when the velocity feedback value is greater than the speed setpoint, DC link voltage for rated voltage 125% AB PLC maintenance, more than 115% of the limit set value; line voltage c) drive has In the rolling process, the drive roller motor speed control will rise, after leaving the roller steel roller motor speed to the original speed, because this drive is not installed brake deceleration; exceeds the upper limit is to limit the braking current through the voltage regulator to maintain the DC link voltage does not exceed 115% of the limit set value (the default), because the line voltage is too high, the DC link voltage exceeds the set limit, at the time of deceleration voltage regulator work, causing the brake current is very small, the motor speed does not drop down inverter repair, and in the rolling, grid load increased, the DC link voltage is less than 115% of the limit setpoint, the brake function returned to normal . At the time was unable to reduce the grid voltage, the DC link voltage setpoint limit increased to 127%, the drive is working properly. During shutdowns, we changed the gear power transformer according to the situation, so that the line voltage of the inverter within the permissible range, then the drive is working properly. Shenyang, China Electric Co., Ltd. to undertake the industrial automation and control system design, installation, engineering and maintenance; professional maintenance States converter, DC governor, PLC programmer repair operations. Drive repair entry - good or bad light emitting diode emitting diode test test good or bad, positive and negative resistance can be tested in accordance with test method ordinary silicon diodes. Refers to the bell multimeter dial in R * 100 or R * 1K file, along with the black pen then the light-emitting diode cathode elevator inverter repair, the red pen then negative, as measured forward resistance should be 20 = 40K; pick-emitting diode anode with a black pen , the red pen then positive, measured reverse resistance should be greater than 500K or more. With a digital multimeter dial diode stalls, black pen then West Germany emitting diode cathode inverter repair, the red pen then negative, resistance is infinite. Black pen then the negative light-emitting diodes, the red pen then positive, there will be micro-light emitting diodes indicate normal. omron plc repair, drive repair Anshan, Shenyang, Shenyang on China by the China Electric Limited. Shenyang Electric Co. on people (www.zsmsy.com) strong, credible, in other industries, such as Shenyang, Liaoning province has accumulated a large number of loyal customers. The company better work attitude and constantly improving people and innovative ideas will lead you to walk hand in hand on the Shenyang brilliant, for a better future!