52 ALARM — Excessive error 1

Check the excessive error detection width parameter SV023 (OD1) for servo, or SP102, SP154, SP155, SP177, SP193, SP218 for spindle modes. If the setting is too small compared to the standard value, increase the value appropriately.

Check the position detector polarity parameters: SV017/bit4 (Servo), SP097/bit5 (Orientation), SP129/bit5 (C-axis), SP177/bit5 (Spindle sync), or SP193/bit5 (Sync tap). If the polarity is reversed, correct the parameter setting.

Check if the power supply unit's CHARGE lamp is lit and measure the voltage at the PN terminals (L+, L-). If there is no voltage or the voltage is significantly low, repair the PN wiring between the units or replace the power supply unit.

Inspect the motor power lines (U, V, W). Ensure the phase order is correct and the cable is not mistakenly connected to the motor for another axis. If any connections are incorrect or loose, reconnect them to the correct terminals securely.

Observe the machine operation and current monitor. If the acceleration/deceleration time constant is too short or the speed loop gain (VGN1) is too low, the motor cannot track the command. Adjust the speed loop gain or increase the acceleration/deceleration time constant.

Verify that the motor brakes are releasing completely and inspect the machine system for mechanical binding, heavy friction, or bent ball screws. Repair the brake circuit or the mechanical system to ensure smooth movement.

Cross-connect the position detector with another known working axis drive unit. If the alarm moves to the other axis, the detector or its cable is faulty and must be replaced.

If the parameters, PN voltage, wiring, mechanics, and detectors are all normal, the fault lies within the drive unit or the motor. Replace the drive unit. If the alarm persists, replace the motor.