2703

Common Causes

• Workpiece not seated or clamped correctly in the chuck
• Chucking air pressure switch not actuating (low air pressure or faulty switch)
• Pressure switch input stuck ON before the detection command
• Grip limit switch or grip confirmation unit malfunction

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code 1 = Air pressure switch failed to come ON after chucking error detection ON command M133.; code 2 = Pressure switch input was already ON when the detection ON command was given.; code 3 = Grip limit switch did not function when the grip confirmation unit advanced on M133.; code 4 = Air pressure switch failed to come ON after tailstock detection ON command M433.; code 5 = Air pressure switch failed to come ON after 2nd chucking detection ON command M633.; code 6 = Air pressure switch failed to come ON after tailstock tool detection ON command M1191.
2. 2Read the code: 1 means the air pressure switch did not come ON after M133; 2 means the pressure switch input was already ON when M133 was given; 3 means the grip limit switch failed during grip confirmation; 4, 5 and 6 are the same air-pressure failures for the tailstock (M433), 2nd chuck (M633) and tailstock tool (M1191) circuits.
3. 3For code 1, 4, 5 or 6, check the chucking air supply pressure and the air pressure switch itself; confirm the switch actuates when the chuck actually closes on a workpiece.
4. 4For code 2, find why the pressure switch input was already ON: a stuck switch, shorted wiring or air already trapped in the detection line.
5. 5For code 3, inspect the grip confirmation unit and grip limit switch for correct advance and switch actuation.
6. 6Open the chuck, re-seat the workpiece correctly as the manual directs, then re-run the chucking confirmation command and verify the pressure switch input toggles cleanly.