Nexen SC100 964420 - Manual (Page 14)

FORM NO. L-21163-C-0808 14
TROUBLESHOOTING
WEB GUIDE SENSORS
Z
ERO
A
DJUSTMENT
1. Apply Power to the SC100.
2. Cover the sensor window completely with an
opaque material (See Figure 20).
3. Connect a voltmeter to terminals 5 (+) and 6 (-).
4. Adjust Z1 until the voltmeter reads 0.025 VDC.
5. Connect a voltmeter to terminals 7 (+) and 8 (-).
6. Adjust Z2 until the voltmeter reads 0.025 VDC.
S
PAN
A
DJUSTMENT
1. Uncover the sensor window.
2. Connect a voltmeter to terminals 5 (+) and 6 (-).
3. Adjust S1 until the voltmeter displays 10.0 VDC.
NOTE: If using one sensor, skip steps 4 through 6.
4. Connect a voltmeter to terminals 7 (+) and 8 (-).
5. Adjust R4 until the voltmeter displays 10.0 VDC.
Figure 20
GENERIC SENSORS
Z
ERO
A
DJUSTMENT
1. Apply Power to the SC100.
2. Unload the sensor or sensors making sure their
outputs represent the minimum value or at rest
condition.
3. Connect a voltmeter to terminals 5 (+) and 6 (-).
4. Rotate Z1 until the voltmeter reads 0.025 VDC.
5. Connect a voltmeter to terminals 7 (+) and 8 (-).
6. Rotate Z2 until the voltmeter reads 0.025 VDC.
S
PAN
A
DJUSTMENT
1. Apply a known load to the sensor 1.
2. Connect a voltmeter to terminals 5 (+) and 6 (-).
3. Rotate S1 clockwise to increase the reading to the
desired voltage level for the load applied.
NOTE: If using one sensor, skip steps 4 through 6.
4. Connect a voltmeter to terminals 7 (+) and 8 (-).
5. Rotate S2 clockwise to increase the reading to the
desired voltage level for the load applied.
6. Repeat the Zero Adjustment and Span Adjustment
procedures detailed above.
NOTE: Span Adjustments procedures may offset the
Zero Adjustment settings. Repeating both procedures
will ensure that settings are accurate.
7. Set the Output Mode switch to the desired setting,
either Individual or Summed (See Switch Settings in
SETUP section).
6. Repeat the Zero Adjustment and Span Adjustment
procedures detailed above.
NOTE: Span Adjustments procedures may offset the
Zero Adjustment settings. Repeating both procedures
will ensure that settings are accurate.
7. Set the Output Mode switch to the desired setting,
either Individual or Summed (See Switch Settings in
SETUP section).
Problem Possible Cause Quick Test Corrective Action
Power LED is not lit.
No power or incorrect
power to SC100 Test terminal 1 (+) and terminal 2 (-)
with a voltmeter. Check wire connections and/or
replace power supply.
SC100 Output does
not change with load.
Incorrect power
supply connections
Test terminals 1 (+) and 2 (-) and
terminals 3 (+) and 4 (-) with a
voltmeter.
Check wire connections and/or
replace power supply.
Sensor inputs wired
backwards
Test terminals 9 (+) and 10 (-) and
terminals 15 (+) and 16 (-) with a
voltmeter.
If test shows a negative voltage,
swap sensor leads.
Incorrect excitation
voltage
Compare adjustable excitation
voltage with sensor specifications.
Adjust excitation voltage
potentiometer for correct voltage.
Incorrect polarity on
SW sensors.
Refer to Sensor Connections
Diagrams.
Check wire connections; make
sure red and black wires are
swapped on the No. 2 sensor.
Span does not reach
required voltage level.
Wrong GAIN setting Refer to Switch Settings.
Switch the input GAIN switch
and adjust span potentiometer.