Cause 1: Coupling blades in the motor socket are incorrectly coupled.
- Adjust the position of the coupling plate.
Cause 2: The connection voltage is too low.
- Connect the motor to the correct voltage (see rating plate) or change to the motor with the correct voltage.
Cause 3: The weight of the load and lifting tool exceeds the arm’s maximum lifting capacity and the pressure limiting valve on the hydraulic unit does not open properly.
- Reduce the load and adjust the pressure relief valve according to the adjustment instructions.