6.4 Fault Detection 126 SIEP C710606 33A OYMC AC Drive – J1000 User Manual Motor overheated by overexcitation operation. • Overexcitation increases the motor losses and thereby the motor temperature. If applied too long, motor damage can occur. Prevent excessive overexcitation operation or apply proper cooling to the motor. • Reduce the excitation deceleration gain (n3-13). • Set L3-04 (Stall Prevention during Deceleration) to a value other than 4. Output current fluctuation due to input phase loss Check the power supply for phase loss. LED Operator Display Fault Name oL2 Drive Overload The thermal sensor of the drive triggered overload protection. Cause Possible Solution Load is too heavy.
Reduce the load. Cycle times are too short during acceleration and deceleration. Increase the settings for the acceleration and deceleration times (C1-01 through C1-04). Voltage is too high for the V/f characteristics. • Adjust the preset V/f pattern (E1-04 through E1-10). This will mainly involve reducing E1-08 and E1-10. • Be careful not to lower E1-08 and E1-10 excessively because this reduces load tolerance at low speeds. Drive capacity is too small. Replace the drive with a larger model. Overload occurred when operating at low speeds. • Reduce the load when operating at low speeds. • Replace the drive with a model that is one frame size larger. • Lower the carrier frequency (C6-02).
Excessive torque compensation. Reduce the torque compensation gain (C4-01) until there is no speed loss but less current. Output current fluctuation due to input phase loss Check the power supply for phase loss. LED Operator Display Fault Name oL3 Overtorque Detection 1 The current has exceeded the value set for torque detection (L6-02) for longer than the allowable time (L6-03). Cause Possible Solution Parameter settings are not appropriate for the type of load. Check the settings of parameters L6-02 and L6-03. There is a fault on the machine side (e.g., the machine is locked up). Check the status of the load. Remove the cause of the fault.
LED Operator Display Fault Name oPr External Digital Operator Connection Fault The external operator has been disconnected from the drive. Note: An oPr fault will occur when both of the following conditions are true: • Output is interrupted when the operator is disconnected (o2-06 = 1) • The run command is assigned to the operator (b1-02 = 0 and LOCAL has been selected) Cause Possible Solution External operator is not properly connected to the drive. • Check the connection between the operator and the drive • Replace the cable if damaged • Turn off the drive input power and disconnect the operator. Next reconnect the operator and turn the drive input power back on.
LED Operator Display Fault Name ov Overvoltage Voltage in the DC bus has exceeded the overvoltage detection level. • For 200 V class: approximately 410 V • For 400 V class: approximately 820 V (740 V when E1-01 is less than 400) Cause Possible Solution Deceleration time is too short and regenerative energy flows from the motor into the drive. • Increase the deceleration time (C1-02, -04). • Install a braking resistor or a dynamic braking resistor unit. • Enable stall prevention during deceleration (L3-04 = “1”). Stall prevention is enabled as the default setting. Excessive braking load. The braking torque was too high, causing regenerative energy to charge the DC bus.
Reduce the braking torque, use a braking option, or lengthen decel time. Surge voltage entering from the drive input power. Install a DC reactor. Note: Voltage surge can result from thyristor convertor and phase advancing capacitor using same drive main input power supply. Ground fault in the output circuit causing the DC bus capacitor to overcharge. • Check the motor wiring for ground faults. • Correct grounding shorts and turn the power back on. Excessive regeneration when overshoot occurs after acceleration. • Lengthen the S-curve at acceleration end. Drive input power voltage is too high. • Check the voltage.
• Lower drive input power voltage within the limits listed in the specifications. The dynamic braking transistor is damaged. Replace the drive. The braking transistor is wired incorrectly. • Check braking transistor wiring for errors. • Properly rewire the braking resistor device. Drive fails to operate properly due to noise interference. • Review the list of possible solutions provided for controlling noise. • Review the section on handling noise interference and check the control circuit lines, main circuit lines and ground wiring.