Flowserve DFP17 - Manual (Page 28)

28 DataFlo Digital Electronic Positioner DFP17 Installation, Operation and Maintenance Instructions WCAIM2037
7.0 TROUBLESHOOTING
7.1 General
The following sections and charts are a troubleshooting guide for
servicing the Positioner, should a malfunction occur. If the
problem cannot be solved, the unit should be returned to the
factory for service.
The first thing to be checked, before proceeding to the
troubleshooting guide, is to determine if the malfunction is in the
Positioner, or in the actuator. To do this for AC boards, remove
the red and black Positioner leads from terminals 3 and 4 of the
actuator, and the AC line connections from terminals 1 and 2.
Tape these leads. Using a test cable, apply power to actuator
terminals 1 and 3. The actuator should rotate CCW until stopped
by the CCW limit switch. Then apply power to terminals 1 and 4
to check CW actuation and the CW limit switch.
For Digital Positioner-240 VAC Positioner only, switches do not
directly limit travel. Exercise caution not to override limit
switches. Operate the unit to its limits in each direction, to
assure that the basic actuator is functional.
If the AC actuator does not operate, check wiring from the
terminal strip, through the limit switches to the motor and
capacitor. For 240 VAC actuator with Digital Positioner, check
wiring from the terminal strip to the capacitor and to the motor.
Check switch continuity. Check for an open motor winding, and
check for a shorted capacitor. If the problem in the actuator still
cannot be determined, return the unit for service. If the actuator
functions properly, then proceed to the troubleshooting guide.
For DC boards, remove red and black leads coming from
motor(s) at terminals 3 and 4. Connect these leads to power
supply to check motor(s) operation. If motor(s) run properly,
then proceed to the troubleshooting guide or return unit
for service.
To facilitate troubleshooting a Positioner, it would be
advantageous on resistive input units to connect a potentiometer
directly to the signal input terminals in place of the standard
process input. Use a 150 ohm or 1000 ohm potentiometer
depending on which model is used. Figure 11 shows a schematic
of a simple test unit that can be connected to the input terminals
to stimulate the process signal for a milliamp rating.
7.1.1 Cam Adjustment
The actuator cams should actuate the limit switches 1° to
3° after the actuator stops at either the fully open or fully
closed position.
If the actuator is closed at 0 degrees, the limit switch
must actuate by the time the actuator is at the minus 1 to
3 degree position. Similarly, at the open or 90 degree
position, the limit switch must actuate by the time the
actuator is at the 91 to 93 degree position.
NOTE: See CAUTION in section 4.1.3.
7.1.2 Check Fuse F1
Check fuse F1 to see if it is blown. If it is, replace it with
Littlefuse PICO II very fast acting fuse rated at 62 mA.
(Newark part number 94F2146).
For DC boards, also check fuse F2 to see if it is blown. If
it is, replace it with a 1
1 / 4 ", 250 volt, 3 amp fuse,
available through any electrical supplier.
IMPORTANT: To check fuse F1, remove it from circuit and
test with ohmmeter. Resistance should be about 6 ohms.
NOTE: If fuse F1 is blown, excessive voltage (possibly
120 VAC) was applied to the signal input circuit. If so,
correct this condition before changing fuse. See section
A of part 1.1.
7.1.3 Check Basic Actuator for Proper Operation
For AC boards, check basic actuator for proper operation
using the correct AC Voltage.
A. Remove red and black leads coming from AC circuit
board at terminals 3 and 4 (if already installed). Tape
stripped ends of these wires.
B. For AC boards, alternately energize, with the
appropriate AC voltage, terminals 1 and 3 and 1 and
4. The actuator should move clockwise when
energizing terminals 1 and 4, stopping only at the
clockwise limit switch. The actuator should move
counter-clockwise when energizing terminals 1 and 3,
stopping only at the counter-clockwise limit switch.
NOTE: For 240 VAC Digital Positioner only, limit
switches do not directly control motor. Therefore, the
actuator will not stop when the limit switches trip. Use
care not to drive the actuator past its normal limits.
Run the actuator to its limits in each direction, to
assure proper operation of the actuator.
7.1.4 Check for Noise Problems
If the circuit board’s light emitting diodes (LEDs) blink or
seem to continuously glow, electrical noise is interfering
with the Positioner’s input process signal. (Always use
shielded cable for the process signal coming to the
Digital Positioner board. Ground the shield at only one
end.) Adjust Digital Positioner as necessary. See Section
4.0.
7.1.5 Replace Circuit Board
The following information is provided if it becomes
necessary to replace the circuit board.
A. Turn off the power supply and disconnect the circuit
board wires from the terminal strip and limit switches.
Disconnect the pot wires at TB1, and also any wires at
TB2. Disconnect 4-20 mA output wires from
connector P1 on circuit board, if used.
B. Remove circuit board mounting screws, nylon
washers, circuit board and insulator board with rubber
grommets from the brackets.
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Worcester Actuation Systems