FCI FLT93B, Installation, Operation & Maintenance Manual

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TROUBLESHOOTING FLT
®
Series FlexSwitch
TM
42 Fluid Components International LLC
Troubleshooting the Control Circuit
1 Is the Yellow Power indicator LED:
Dim,
Off or
Blinking
Yellow LED dim or off
With the power applied, measure the 9-volt reference voltage at P1, pins 2 (blue) to
4 (black). See Figure 3-2 for the location of P1. Verify a voltage of 9 volts DC ±2%
(8.82-9.18 V).
Not OK: Low Reading: A low reading may indicate incorrect power is being
applied. Turn off the power and remove the control circuit. Caution: While the power
is on, use extreme care when measuring the input voltage. Check the input power
wiring on the terminal board and make corrections if necessary. Before reinstalling
the control circuit, apply the input voltage to verify or correct. Check disconnects.
Turn off the power and reinstall the control circuit. Apply power and re-check the
9-volt reference.
Not OK: No Reading: Go to step 2 and check the fuses.
OK: If the 9-volt reference measures correctly and the yellow LED is off, refer to
the Troubleshooting the Flow Element discussion in this section. On remote installa-
tions, the interconnect cable may be miswired or a wire may be disconnected. If the
flow element resistances are not correct contact the factory. If the sensor is OK then
proceed to step 4.
Yellow LED Blinking: For Liquid Flow Applications: Line is Dry. Make sure that the
line is packed. For Gas Flow Applications: Heater power set too high. Set to a lower
value. For Liquid Level Applications: Heater power set too high. Set to lower value.
For Liquid Interface Application: In some cases it is necessary to set the heater
power to the maximum value to achieve the maximum signal difference between the
two liquids. Blinking is okay.
2 Fuse Check Turn off the power and remove the control circuit. For installations using 120/230
VAC, remove F1 and F2. With an ohmmeter, measure the continuity of the fuses. If
one or both of the fuses are open, replace and recheck if the control circuit func-
tions properly. If the one or both fuses open again, contact the factory. If the fuses
are OK but the control circuit does not power up contact the factory.
For installations using 24 VAC/VDC, remove the bottom insulator and locate F3.
With an ohmmeter, measure the continuity across the fuses. If the fuse is open,
replace and recheck if the control circuit functions properly. If fuse opens again,
contact the factory. If the fuse is OK but the control circuit does not power up
contact the factory.
3 Flow switch not responding Is the Mode switch in the “RUN” position?
Is the signal voltage reacting to flow or liquid level movement and is the signal
within the usable range of 0-7.0 volts at P1 pin 1 (red) and 2 (blue)?
Not OK : Go to step 4.