Flowserve Modutronic 20 II Modulating Position Controlle - Manual (Page 24)

Limitorque Actuation Systems Modutronic 20 II FCD LMENIM4002-00 – 08/06
24
Symptom Possible Cause Corrective Action
Units run in one
direction only
1. Shorted output 1a. Verify proper MANUAL direction operation.
Using ammeter, verify proper command signal,
verify all calibrations have been completed
properly. If you still have difficulty calibrating
the Mod 20 II after verifying the above settings,
replace the Mod 20 II.
No LOCK-IN-LAST
POSITION
1. Missing JP1 Jumper 1a. Locate JP1 Jumper on the Mod 20 II board
and verify connections.
Unit will not follow
signal
1. Bad Potentiometer or
Potentiometer is not centered
1a. Check Pot as discussed in item #7. If Pot
is OK, place the actuator at 50% and check the
resistance between terminals 7-1 and 7-2 or 7-2
and 7-3 with an ohmmeter. See “Adjusting the
Actuator Feedback Potentiometer” (Section 4.3).
Input signal does
not result in full
travel of the valve
1. Mod 20 II not calibrated
correctly
1a. See Section 6 to review the calibration
procedure for the Mod 20 II.
2. ZERO and SPAN adjustments
incorrect
2a. Recalibrate according to procedure in Section
6.
Large input signal
variations result in
little or no actuator
movement
1. Improper analog Input Signal
value
1a. Check for proper Input Signal value.
2. Limit Switch 2a. Check for proper setting. (See appropriate
actuator manual for setting the Limit Switches.)
3. DEADBAND adjustment 3a. Check the DIP Switch accuracy adjustments
shown in Table 6.1.
4. ZERO and SPAN adjustments 4a. Recalibrate according to procedure in Section
6.