The "Over Temperature PM1" error on a KUKA robot typically indicates that the Power Module 1 (PM1) has exceeded its safe operating temperature. PM1 is usually associated with one of the axes of the robot, and overheating can be caused by various factors.

Causes of Over Temperature PM1:

1. Extended Operation at High Loads:

   • If the robot has been operating under heavy loads or at high speeds for an extended period, the power module may overheat due to the increased demand on the motors and drives.

2. Insufficient Cooling:

   • The cooling system (fans, ventilation, etc.) for the controller or the robot may not be functioning properly, leading to insufficient heat dissipation from the power module.

3. Blocked Airflow:

   • Dust, debris, or obstructions in the airflow path can cause inadequate cooling, leading to overheating of the power module.

4. Ambient Temperature:

   • If the robot is operating in an environment with a high ambient temperature, this can contribute to the power module overheating.

5. Faulty Temperature Sensor:

   • The temperature sensor in the power module may be faulty, giving a false over-temperature reading.

6. Aging or Faulty Components:

   • Over time, components such as capacitors, fans, or thermal paste in the power module may degrade, leading to overheating issues.

Steps to Troubleshoot and Resolve:

1. Allow the System to Cool:

   • Immediately stop the robot’s operation and allow the system to cool down. Power off the controller and wait for some time before restarting.

2. Check Cooling Fans and Ventilation:

   • Ensure that all cooling fans within the controller cabinet and on the robot are functioning correctly. Listen for unusual noises that might indicate a fan failure.
   • Inspect the ventilation openings and filters for dust or debris that might be obstructing airflow. Clean or replace filters if necessary.

3. Verify Ambient Conditions:

   • Check the ambient temperature of the operating environment. Ensure that it is within the recommended range specified by KUKA for the robot’s operation.
   • Improve ventilation or air conditioning in the area if the temperature is too high.

4. Inspect for Blockages:

   • Open the controller cabinet and check for any objects or dust buildup that might be blocking airflow to the power module. Clean the area thoroughly.

5. Monitor Operational Load:

   • Review the recent operational parameters of the robot. If it has been operating at high loads or speeds, consider reducing the workload or programming more frequent breaks to allow the system to cool down.

6. Check Temperature Sensor:

   • If you suspect the temperature reading might be incorrect, you may need to check the temperature sensor or have it tested by a technician. If faulty, the sensor should be replaced.