Flowserve Modutronic 20 II Modulating Position Controlle - Manual (Page 23)

2
Limitorque Actuation Systems Modutronic 20 II FCD LMENIM4002-00 – 08/06
flowserve.com
7
Troubleshooting
Symptom Possible Cause Corrective Action
Unit will not operate
electrically in AUTO
or MANUAL
1. No power to unit 1a. Verify Power Supply is electrically correct and
present at actuator.
1b. Verify Power Leads are connected in accor-
dance with the applicable wiring diagram.
1c. Inspect for Blown Fuse, tripped Circuit Breaker,
or OPEN Disconnect Switch.
2. Wiring problems 2a. (LYs with internal Mod 20 II board) Check
push-on terminal between the Integral PC Board
and the Micro Switches. Check for bad Micro
Switches on SW Station.
3. Starter wires loose 3a. Check all the connections on the Reversing
Starter.
4. Thermal overloads have tripped 4a. Measure continuity in the circuit. If you have
an open circuit, wait for the motor to cool, then try
to operate actuator. You may need to reduce the
number of starts per hour.
Unit will not operate
electrically in AUTO
1. No power to Mod 20 II 1a. Verify incoming 18 VAC between terminals
P1-1 and P1-2 on Mod 20 II board.
2. Bad Mod 20 II board 2a. Check board for burnt or broken components.
Bypass Mod 20 II board using Pushbuttons to
verify proper operation. See your specific wiring
diagram for bypassing Mod 20 II board.
3. Command Signal Leads
reversed
3a. (L120 Interconnect PC Board) Check that the
Command Signal Leads are wired to terminal
TB16(+) and TB17(-).
4. Bad Potentiometer 4a. Check the Potentiometer with an ohmmeter
electrically in AUTO. Unplug the Pot from the
Integral PC Board and take a meter reading
between pins 7-1 and 7-2 or 7-2 and 7-3. The
meter should have a steady reading. If the meter
reading goes to zero or jumps around, verify that
the Pot is centered. Replace the Pot if needed.
Check for Cables that may have been pinched
between the Housing Cover or Integral Assembly.
5. All DIP switches turned Off 5a. Check DIP switches. Refer to Calibration
Procedure (Section 6), Step 15a.
Continued on page 24