Maintenance; Motor And Gears; Adjusting The Brake; Replacing The Position Sensor - ABB Contrac LME620AI Instructions Manual

10.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 de-
rives the remaining operating time until the next routine maintenance is required. Use the configuration
program for viewing this information.

10.1Motor 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 thrus rod surface
- Check the motor pinion gear and the respective mating gear.
- Replace the motor's rotary shaft seal and ball bearings.
- Check the position sensor.
The actuator position may be changed accidentally by the repelling power of the valve when the brake
is released!

10.2Adjusting the Brake

In automatic mode the brake is permanently released. Therefore, it is not exposed to wear and does
not require any re-adjustment.

10.3Replacing the Position Sensor

10.3.1 Dismounting
- drive actuator into 50% position (referred to rated actuator stroke)
- delete the current position setting by pressing the drive buttons on the LCP for at least 5 sec.
- switch-off the voltage supply
- undo the two fastening screws (1) of the position sensor and pull the sensor out of the gears
- disconnect the ribbon cable plug from the PCB
10.3.2 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 11.
- align the sensor and its gears with the actuator; set the first toothed gear in 03.00 o'clock position
(see Figure 12) 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.
- connect the plug (5) of the ribbon cable to the PCB.
- fasten the screws (1) tightly.
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