1791

Common Causes

• Program issues M93/M92 without first unclamping (or clamping) the chuck as required
• Chuck failed to actually open or close (hydraulic pressure, chuck actuator)
• Faulty or misadjusted chuck open/close limit switches so the control reads the wrong chuck state
• Door close limit switch OFF or bar feeder ready signal OFF when M93 was issued

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code 1 = Bar feeder advance (M93) commanded while the chuck was not unclamped; code 2 = Bar feeder retract (M92) commanded while the chuck was not unclamped; code 3 = Bar feeder retract (M92) commanded while the chuck was not clamped; code 4 = Bar feeder advance (M93) commanded with the door close limit switch OFF; code 5 = Bar feeder advance (M93) commanded with the bar feeder ready signal OFF
2. 2Read the code: 1=M93 with chuck not unclamped, 2=M92 with chuck not unclamped, 3=M92 with chuck not clamped, 4=M93 with door close limit switch OFF, 5=M93 with bar feeder ready signal OFF.
3. 3For codes 1-3, check the program sequence: confirm the chuck open/close M command is executed and completed before the M92/M93 bar feeder command, and add a dwell or confirmation if needed.
4. 4Operate the chuck manually and watch the chuck clamp/unclamp status on the control: if the chuck physically moves but the status does not change, inspect the chuck open and close limit switches for adjustment, contamination, or failure.
5. 5For code 4, close the guard door fully and verify the door close limit switch changes state; adjust or replace the switch if the door is closed but the signal stays OFF.
6. 6For code 5, check the bar feeder side: confirm the bar feeder is powered, in ready state, and that the ready signal cable/connection between bar feeder and NC is intact.