TROUBLESHOOTING
ON-LINE FAILURE
6 - 6
I-E96-315B
®
No servo drive from
the servo amplifiers
(continued)
Bad connection
to the servo
valve, defective
servo valve
3. Verify that there is a servo drive and return signal for each servo
output.
4. If there is no servo valve drive signal, check the continuity of the
connecting cables.
5. If the connecting cables are open or show an unusually high
impedance, replace the cables.
6. If the cable continuity is good and there is no servo drive output,
check the servo valve and replace it if defective.
No LVDT primary
excitation voltage
Bad LVDT, bad
cable
Check the LVDT primary.
1. Connect an oscilloscope to TB1 terminal 1 (terminal 17 on the
TM). Ground the oscilloscope on the system common.
2. Verify that there is an excitation voltage on the primary side of
the LVDT at the selected frequency.
3. Connect the oscilloscope to TB1 terminal 2 (terminal 16 on the
TM) Ground the oscilloscope on the system common.
4. Verify that there is a return signal on the primary side of the
LVDT at the selected frequency.
5. If there is no LVDT excitation signal, check the continuity of the
connecting cable.
6. If the connecting cables are open or show an unusually high
impedance, replace the cables.
7. If the cable continuity is good and there is no LVDT excitation,
check the LVDT and replace if defective.
No LVDT secondary
response
Bad connection
to the LVDT,
bad transformer
Check the LVDT secondary.
1. Connect an oscilloscope differentially across TB1 terminals 3
and 4 and do steps 2 through 5. Then connect the oscilloscope dif-
ferentially across TB1 terminals 5 and 6 and repeat steps 2
through 5.
2. Enter a position demand to change the actuator position.
3. Verify that there is a differential voltage on each LVDT second-
ary at the selected frequency. The differential voltage will change
during a position demand.
4. If there is no differential voltage on the LVDT secondaries,
check the continuity of the connecting cables.
5. If the cable continuity is good and there is no differential voltage
on the LVDT secondaries, check the LVDT and replace if
defective.
HSS fails to cali-
brate, all process
hardware checks
good, there are no
configuration errors
HSS failure
Replace the HSS module.
Replacing the HSS
fails to correct the
calibration failure
Contact Bailey Controls for assistance.
Table 6-1. Troubleshooting On-Line Failures
(continued)
Problem
Cause
Action
