Flowserve DFP17 - Manual (Page 30)

30 DataFlo Digital Electronic Positioner DFP17 Installation, Operation and Maintenance Instructions WCAIM2037
7.3 Troubleshooting Guidelines
Use the following troubleshooting guidelines to isolate
problems/bad components.
Prior to beginning any procedure, read all of Check, Action, and
Note and Caution sections.
Flow Control
Worcester Actuation Systems
CHECK ACTION NOTES AND CAUTIONS
7.3.1 Check for proper AC/DC power to Correct as necessary.
actuator and circuit board. See
Figures 4, 5, 6 or 7.
7.3.2 With power off, check for broken Repair broken wires and
wires and/or loose connections. tighten loose connections.
7.3.3 With power off, check to see if Remove F1 from socket pins Before restoring power, try to determine
fuse F1 is blown. (For DC boards, and check for continuity what caused F1 to blow and correct
see section 7.1.2 also.) through fuse with an problem. See Section 3.2 note and
ohmmeter. If F1 is bad, section A of Section 1.1,
replace it with a new fuse. and also section 7.1.2.
7.3.4 Check operation of basic actuator See Section 7.1. This check will isolate the problem to either
per Section 7.1. the actuator or the circuit board.
7.3.5 Check for proper range of input Use ammeter, voltmeter or See models listed at beginning of IOM for
signal. ohmmeter to verify input ranges. 4-20 mA is most common.
signal range.
7.3.6 With power off, check calibration A quick check to see if this is When trying to move the valve manually
of feedback potentiometer per the problem is to declutch the with the clutch disengaged, be certain that
section D of Section 1.1. actuator shaft and reposition the wrench fits properly on the flats of the
the shaft to about 45° (if actuator shaft. Improper fit can cause shaft
valve torque permits). If the damage with consequent damage to cover
actuator now runs normally bearing surface. Stay within the preset
in each direction (after clutch bearing surface. Stay within the preset
reengages), recalibrate the quadrant of operation. See section C of
feedback potentiometer. Section 1.1.
7.3.7 Check to see that varying input If LEDs do not turn on and The turning on and off of the LEDs is
signal from 4-20 mA causes the off, replace board. indicative that the input side of the circuit
light emitting diodes (LEDs) to board is OK.
turn on and off individually.
7.3.8 Check the operation of the If intermittent or jittery Increasing the deadband may help to
Positioner with a portable, operation stops, it is alleviate the problem.
battery operated signal source. indicative of a noisy online
signal input. To avoid
damaging the actuator, it is
necessary to “clean up” the
signal. Also, follow the
shielding guidelines of
sections 1.2 and 1.2.3.
7.3.9 Check the motor run capacitor for Replace as necessary. Disconnect all leads from capacitor
a short, excessively high leakage terminals (power off) prior to testing. Do
and low capacitance. Use a not exceed rated voltage of capacitor. Make
capacitance meter to check. certain that capacitor is discharged before
(AC boards only.) reconnecting.