AMOT 10GEF, Operation And Maintenance Manual, Page: 47 / 80

47
Electric Actuator
OMMG00012 Rev 12 – NOV 2019
Fig 15 Potentiometer Adjustment
1 Loosen the grubscrew (8) of the large spur gear (7) and slide the gear
down the shaft (17) to disengage from the small spur gear (6).
2 Manually wind the actuator to mid position determined by counting the
turns between the mechanical end stops and then winding the total
number of turns divided by 2.
3 Connect an ohmmeter to terminals 20 and 22 on the terminal strip (whole
track of potentiometer).
4 Determine the centre value of the potentiometer track by dividing the
reading on the ohmmeter by two.
5 Connect the ohmmeter to terminals 21 and 22 on the terminal strip (pot
wiper to end of track).
6 Rotate the potentiometer shaft until the ohmmeter indicates the centre
value determined at step 4.
7 Rotate the large spur gear (7) on the shaft until the grubscrew (8) is in
an accessible position for tightening.
8 Slide the gear up the shaft until it engages with the small spur gear (6).
9 Ensure the ohmmeter still indicates the centre value. Adjust by rotating
the large spur gear on the shaft as necessary.
10 Tighten the grubscrew (8).
11 Manually wind the actuator to each end stop and record the ohmmeter
indication.
12 Ensure that the centre section of the potentiometer track is being used by
checking the ohmmeter readings at each end of travel eg. 40 Ω and
960
Ω
readings indicate an even distribution on a 1 k
Ω
track.
13 Remove the ohmmeter connections.
14 Ensure that the actuator cover O ring is correctly fitted and undamaged.
15 Refit the actuator cover and secure with the socket head cap screws.