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23 ALARM — Excessive Speed Deflection 1

MitsubishiMDS-C Series (Drive)·7-step diagnostic tree·8 languages

Interactive troubleshooter

Step 1 of 7

Check the U, V, and W phase wiring between the spindle drive unit and the spindle motor. If the wires are not connected correctly, reconnect them properly.

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All diagnostic steps

STEP 1

Check the U, V, and W phase wiring between the spindle drive unit and the spindle motor. If the wires are not connected correctly, reconnect them properly.

STEP 2

Inspect the speed detector connectors on both the drive unit side and the detector side. Disconnect and securely reconnect them by hand to ensure they are not loose. Turn the power OFF and check the detector cable with a multimeter. Replace the cable if a fault is found.

STEP 3

Check the spindle parameter settings for SP034, SP040, SP055, and SP257 to SP384. If the values are incorrect, set them to the correct standard values for the motor.

STEP 4

Measure the acceleration/deceleration time constants, specifically the time required to reach the reverse run maximum speed from the forward run maximum speed. If it takes 12 seconds or more, increase the setting value of parameter SP055 (excessive speed deviation timer).

STEP 5

If the alarm occurs during cutting operations, check the load value using the spindle monitor. If the cutting load is 120% or higher, reduce the cutting load by altering machining conditions.

STEP 6

Check the PLG (speed detector) output waveform using an oscilloscope. If the waveform is abnormal, adjust the PLG output waveform. If it cannot be adjusted, replace the speed detector.

STEP 7

If the alarm persists after checking wiring, parameters, acceleration time, and the detector waveform, replace the faulty MDS-C drive unit and contact authorized Mitsubishi service.