User Manual EM303B General Purpose Inverter 10 Troubleshooting 10.1 Faults When anything unexpected happens, the corresponding trip code and parameters will be displayed on the keypad, fault relay is on and fault output terminal is on, inverter output stops. When fault occurs, if the motor is running, it will coast to stop. See Table 9-1 for EM303B fault trips and troubleshooting. Table 9-1 EM303B Fault Trips and Troubleshooting 164 Trip Trip Cause Corrective Action Code Short Circuit 1. Short circuit between inverter output phases, or between the output phases and ground. 2. IGBT is damaged. 3. On-site interference. 1. Check if there is a short circuit. 2.
Check, take corrective actions, and then reset. 2. Technical support is required. SC Instantaneous Overcurrent 1. Short circuit between inverter output phases or between the output phases and ground. 2. The acceleration/deceleration time is too short. 3. In V/F control mode, the setting value of torque boost is too big. 4. The motor is rotating when inverter starts. 5. The capacity of motor exceeds that of inverter, or the load the too heavy. 1. Check, take corrective actions, and then reset. 2. Prolong acceleration/deceleration time 3. Reduce setting value of torque boost. 4. Set speed search start enabled, or start DC brake. 5. Replace with applicable motor or inverter.
HOC Stable Overcurrent SOC Instantaneous Overvoltage 1. Deceleration time is too short. The motor regenerative energy is too much. 2. Power supply voltage is too high. 1. Prolong deceleration time. 2. Install applicable braking unit and braking resistor. 3. Lower the power supply voltage to the rated voltage. HOU Stable Overvoltage 1. Voltage of power grid is too high. 2. Deceleration time is too short. 1. Lower voltage to the rated voltage. 2. Prolong the deceleration time. SOU