Position Feedback Potentiometer (Option) - Bernard SD Serie Instructions De Mise En Service

6. SETTING OF TORQUE LIMIT SWITCHES
IMPORTANT : the torque limit switch design of BERNARD actuators gives a
short duration contact only. On request, relays holding this contact
maintained can be fitted into the actuator.
Actuators are set and tested in accordance with the torque stated on orders.
If no torque is specified, the actuator is supplied with torque springs set to the
maximum output (refer to our catalogue technical datasheets).
If necessary, this torque setting can be readjusted by rotating the nuts which
compress the torque springs. So the torque can be increased or decreased
by tightening or loosening the nuts. Please consult us.

7. POSITION FEEDBACK POTENTIOMETER (OPTION)

The potentiometer used for actuator signal feedback is driven by the travel
cam block system.
The potentiometer has no mechanical stop and has a non-resistive area
(dead zone) at both the beginning and end of track.
0% position corresponds to a closed valve. 100% to an open valve.
Circuit board mounted version
To mount the potentiometer device on the switch plate, clip it without the
position indicator on the camblock and screw it on the support column. Screw
the position indicator back.
Setting of potentiometer zero is achieved thanks to the "0% postion" screw.
Drive the actuator to the closed position.
Resistance value is measured between terminals 16 and 17.
Hold the pinion located just under the plate with the "0% position" marking
while driving the potentiometer screw. Adjust the potentiometer so that the
resistance value exceeds 0 Ohm and regularly increases then turn
backwards to reach a value as close to 0 Ohm as possible.
Drive the actuator to the open position and write down the resistance value
corresponding to the 100% position.
Come back to the closed position and check that, for the 0% position, the
resistance shows a close to zero repeatable value.
On support column mounted version (OA type of actuactors)
To mount the potentiometer device, screw the support column on the
mounting plate and engage the driving pinion into the camblock wheel.
To adjust the potentiometer resistance value, loosen the nut with the wrench
and rotate potentiometer until the signal requested is archieved.
To set the 0%, drive the actuator to the closed position.
Resistance value is measured between terminals 16 and 17.
Rotate the potentiometer so that the resistance value exceeds 0 Ohm and
regularly increases then turn backwards to reach a value as close to 0 Ohm
as possible.
Retighten nut after setting.
Drive the actuator to the open position and write down the resistance value
corresponding to the 100% position.
Come back to the closed position and check that, for the 0% position, the
resistance shows a close to zero repeatable value.
Note : If actuator is equipped with 2 potentiometers, each potentiometer is set
independently of the other.
Signal inversion :
To inverse the signal variation direction, invert potentiometer wires on the
actuator terminal board (e.g. for a connection on 16/17/18, invert 16 and 18).
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