Appendix A - Homing Pumps - Graco PR70 Operation & Maintenance Manual

Appendix A - Homing Pumps

Appendix A - Homing Pumps
Setting Home:
The actuator has an absolute encoder that has a battery
backup to store the motor position when the power is
turned off. The home position is set at the factory and
would only need reset if the encoder cable between the
servo drive and servo motor is disconnected.
NOTE: If the electrical connections between the
encoder and drive need to be disconnected make sure
the actuator is in the home position before disconnect-
ing the cable. This ensures everything is in position
when the connector is reattached and the below steps
will not be necessary to perform.
1. Login as supervisor and go to the SETUP HOME
screen.
2. Remove the motor from the actuator.
3. Using a wood dowel rod (or equivalent); turn the
actuator lead screw manually to locate the home
position. CW retracts the pumps, CCW extends the
pumps.
4. With pistons installed, manually retract the actuator.
When the pistons are out of the pump tube there is
much less drag.
5. Manually extend the actuator until it becomes hard
to turn. This is the point where the pistons are enter-
ing the pump tube; the home position. Also note on
a variable ratio PR70 at this point the ratio mecha-
nism is parallel with the back of the frame.
6. Disable the drive. The motor will be able to be
turned manually.
7. Push the Set Home pushbutton.
8. Press the Enable Drive pushbutton.
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9. Reattach the motor to the actuator.
10. The Actual motor position will now read zero.
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