Automatic Mode Causing Erratic Wrench Behaviour

Occasionally erratic wrench behaviour can occur if certain system conditions exist and the system can stop the wrench before the tightening has completed.

If erratic wrench behaviour is experienced carry out the checks below:

  1. Oil temperature is too low : To overcome this issue remove the wrench from the bolt being tightened and place on the floor so it is free running. Switch the pump to manual mode, set the pressure to maximum (10000psi/690 Bar), then cycle the wrench back and forth allowing the pressure to build to maximum each time. Note: 10-15minutes of manual cycling may be necessary depending on environmental conditions. After the oil temperature has increased switch into Automatic mode, set working pressure, carry out learning cycle and attempt to tighten using automatic mode.

    10-15minutes of manual cycling may be necessary depending on environmental conditions. After the oil temperature has increased switch into Automatic mode, set working pressure, carry out learning cycle and attempt to tighten using automatic mode.

    If the erratic behaviour still exists it is possible that the oil grade is incorrect for the conditions. Try changing the oil to a more suitable grade for the working conditions.

  2. Mixture of Coupling Brands : Although many screw-to-connect couplings claim to be interchangeable there are small internal differences that can cause unstable flow characteristics. This can cause the wrench operation to appear slow and cause the automatic mode to malfunction. To prevent these issues it is recommended that the couplings on the wrench, pump and hoses are all the same model and make.

  3. Old Firmware Installed : Check Firmware number and contact Atlas Copco. If the problem persists fine tuning can be performed to suit specific system conditions, contact Atlas Copco for further advice.