Do not just look at the flashing code on the main screen. Navigate to the or Diagnosis screen on your control. Look up the specific diagnostic bit associated with the alarm text. This tells you exactly which physical switch or relay the PLC thinks is currently open or closed. Step 2: Inspect Physical Fluid Levels and Pressures
The "EX" in EX alarms stands for . These alarms indicate that a condition outside the main CNC control core has been triggered.
Alarm: 5005 / PLC COMMUNICATION ERROR
Excessive heat in the electrical cabinet; check filters/fans. LUBE PRESSURE Oil-air lubricant pressure is too low. Z-AXIS OVERLOAD Z-axis is overloaded during operation. BATTERY LOW Change the battery for memory backup. Execute safety validation test before starting operation. Mori Seiki Alarm Codes Overview | PDF - Scribd
When a proximity switch, pressure sensor, limit switch, or safety door module sends an unexpected signal to the PLC, the machine halts operation and displays an EX code on the screen. Because these are written by the machine tool builder (Mori Seiki) rather than the control manufacturer (Fanuc or Mitsubishi), they relate directly to the physical setup and auxiliary functions of the machine. Key Characteristics of EX Alarms: mori seiki ex alarm list
Many EX errors are caused by tripped thermal overloads or circuit breakers inside the main electrical cabinet. Open the cabinet doors safely and inspect the breaker switches. Look for tripped yellow or red indicators on the motor starters for the coolant pumps, hydraulic pumps, and chip conveyors. 4. Clear the Alarm
The automatic way lubrication system lacks pressure, or the reservoir is empty.
This guide is designed to help operators and maintenance technicians understand the alarm structure, common codes, and troubleshooting steps for Mori Seiki EX lathes (typically running on Mori Seiki MS/MSC or Fanuc-based controls).
This is the strongest point of the Mori Seiki documentation compared to some competitors. Do not just look at the flashing code on the main screen
After registering your machine serial number, download:
The tool turret failed to physically unclamp or index within the allotted time window.
An external E-stop button has been pressed. This could be on the main panel, a chip conveyor, or an integrated bar feeder.
Spindle orientation or indexing failed to complete in the allowed time . Troubleshooting Steps This tells you exactly which physical switch or
The automatic tool changer arm on a machining centre is out of its home position or failed to complete a swap.
The spindle cannot start because the hydraulic or pneumatic chuck is in the open position, or the chuck proximity sensors are misaligned.
The Mori Seiki EX alarm list is not a nuisance—it is a . Each EX code points directly to a sensor, a logic condition, or an operator action that needs attention. By understanding the most common codes (EX1001 to EX1052) and how to systematically troubleshoot them, you can reduce average repair time from hours to minutes.
The turret took too long to unlock, rotate, or lock back into position.
The thermal relay for the coolant pump has tripped. This happens if the pump impeller is jammed with chips or if the motor winding is failing. 2. Door Interlock and Safety Alarms
Hydraulic pressure gauges (typically should read between 3.5 to 4.5 MPa, depending on the machine manual).