Maintenance; Motor And Gears; Adjusting The Brake; Replacing The Position Sensor - ABB PME120-AI Instructions Manual

11. Maintenance

Contrac actuators have a robust construction. As a result, they are highly reliable and require only little
maintenance. The maintenance intervals depend upon the effective load and are therefore not specified
here.
The built-in microprocessor evaluates the actual load factors (e.g. torques, temperatures, etc.) and
derives the remaining operating time until the next routine maintenance is required. Use the configura-
tion program for viewing this information.

11.1 Motor and gears

All maintenance work must be carried out by qualified specialists who have been trained for this task.
As a rule, perform the following routine maintenance works:
- Check the shafts and gears.
- Check the motor pinion gear and the respective mating gear.
- Replace the motor's rotary shaft seal and ball bearings.
- Check the position sensor.
- Change the oil; then make a visual check and check for proper operation.

11.2 Adjusting the brake

The actuator setting may be changed accidentally by the repelling power of the valve when the brake is
released!
In automatic mode the brake is permanently released. Therefore, it is not exposed to wear and does
not require any re-adjustment.

11.3 Replacing the position sensor

11.3.1 Dismounting
- drive actuator into 50% position
- delete the current position setting by pressing the drive buttons on the LCP for at least 5 sec.
- switch-off the voltage supply
- disconnect the connector plug from pcb
- undo the two fastening screws (1) of the position sensor and pull the sensor out of the gears.
11.3.2 Mounting
The toothed gear pair of the position sensor is held in place by a tension spring (3), to ensure sufficient
free motion when the direction of rotation is reversed
- set the stop pin to the center position, as seen in Figure 12
- connect the plug (5) to the PCB
- align the sensor and its gears with the actuator; set the first toothed gear in 11:00 o'clock position
(see Figure 13) onto the drive shaft gear (4)
- slightly move the sensor back and forth to pre-tension the toothed gears with the difference "z" until
the second toothed gear snaps in
- fasten the screws (1) tightly.
1
Figure 12: Position sensor
14
Z
2
1
3
(r00329x1)
1
4
(r00335x1)
Figure 13: Mounting position
1