M9200 Series Electric Spring Return Actuator Product/Technical Bulletin 9
Potentiometer Settings
IMPORTANT: Both zero and span potentiometers
must be adjusted to ensure full
actuator travel and complete
calibration.
The HGA and HGC models have two potentiometers,
zero and span. These potentiometers do not require
adjustment when Jumper W3 is in the fixed position
(factory set). When Jumper W3 is in the adjustable
(ADJ) position, proceed as follows:
Use either Terminals 3 and 5 or Terminals 3 and 4,
a control signal, and a voltmeter. The zero and span
potentiometers can be adjusted as follows without
waiting for the actuator to drive to the final position.
Adjusting the Zero and Span
1. Verify that Jumper W2 is in the 0 to 10 VDC
position, and place Jumper W3 in the adjustable
(ADJ) position. (See Figure 13.)
2. Provide 24 VAC or 24 VDC power to Terminal 1
(Common) and Terminal 2.
3. Connect the Common from the controller to
Terminal 1, and either a voltage signal to
Terminal 5 or a current signal to Terminal 4.
4. Connect Terminals 1 and 3 to a voltmeter to
monitor the calibration output.
5. Use a 1/8 in. (3 mm) flat-blade screwdriver to turn
the zero potentiometer fully CW and the span
potentiometer fully CCW.
6. Apply the minimum (zero point) control signal
required for positioning the actuator at the
minimum position.
7. Monitor DC calibration output. To adjust the zero
potentiometer, turn it CCW until the voltmeter
displays 0 volts or slightly less (-0.1 volt).
8. Adjust the control signal to the maximum voltage
desired to cause full rotation. (Signals greater than
10 volts have no further effect.)
9. Monitor calibration output at Terminals 1 and 3.
Adjust the span potentiometer CW to increase the
calibration output to 10 volts.
10. Verify that the actuator is properly calibrated by
adjusting the control signal to the minimum and
maximum levels.
Example for a zero of 3 VDC and a span of 5 VDC:
a.
Apply a 3-volt control signal to the actuator,
and turn the zero potentiometer CCW until the
calibration output at Terminal 3 is 0 volts.
b.
Apply maximum voltage. (In this case, it is
8 VDC, which results in a span of 5 volts.)
c.
Monitor calibration output at Terminal 3, and
adjust the span potentiometer CW until
10 volts is reached.
Note:
Mechanical movement is not immediate due to
a delay in the actuator’s response to the
control signal.
