Farm Fans C-2120A Operator's Manual page 62

TROUBLE
Control circuit ener-
gized - No ASC panel
shutdown light ON.
Top auger will not
start
CHECKOUT PROCEDURE & INFORMATION
- inlet air blocked
- fan motor failed
b. Backdraft currents during shutdown period.
NOTE: In the event the dryer shuts down, the backdraft currents of hot air passing through the
housing may cause the burner hi-limit to trip open.
• PLENUM HI-LIMIT LIGHTS (Upper & Lower)
Auto-resets after cooling. Indicates Plenum high limit switch has reached 300°F for the following
possible reasons:
a. Plenum temperature set too high, or blocked air flow within dryer perforations.
b. Minimum gas pressure setting is too high.
c. Plenum controller failed.
d. Plenum RTD sensor failed.
e. Plenum High Limit switch failed.
• BURNER LOCKOUT LIGHTS (Upper & Lower)
Auto-resets after cooling. Indicates flame was not sensed for 60 seconds for the following possible
reasons:
a. Burner failed to ignite:
- main shut-off valve was not opened
- minimum fire set too low
- hand valves closed
- insufficient fuel supply
- failed or fouled ignitor plug; also check for defective flame switch
- failed liquid LP solenoid valve
- vapor high limit sensor has reached 220°F and has closed the liquid solenoid
b. Burner flame has gone out:
- minimum fire set too low
- insufficient fuel supply
- defective or improperly located flame switch
- failed liquid LP solenoid valve
- vapor high limit sensor has reached 220°F and has closed the liquid solenoid
— UNMONITORED SHUTDOWN DEVICES (No ASC Panel Indicator Lights) —
• DISCHARGE SHUT-OFF SWITCH LIGHT - located on the grain discharge assembly.
May require cleaning of grain from under grain discharge door for switch to reset. Indicates that
unload auger discharge switch has opened for the following possible reasons:
a. Auxiliary unload equipment has failed or overloaded.
b. Discharge door is not seated properly.
c. Discharge proximity switch failed.
• Various circuit breakers (as shown in wiring schematics or Power Panel illustration)
• Overload relays (manual reset required):
- Auxiliary unload relay
- Unload auger overload relay
- Auxiliary load relay
- Load auger overload relay
- Fan overload relays
- SCR overload relay
a. amperage draw on motor is too high
- low voltage
- motor load too high
- failed motor
- shorted motor wires
b. overload heaters improperly sized
c. failed heater strip or relay
d. relay has not been manually reset
e. low voltage
1. Check that top auger circuit breaker is turned ON, also that control circuit is energized and LOAD
AUGER SWITCH is set to ON or AUTO position.
2. Check position of upper auger paddle & its switch box - paddle must be "down" with switch box hor-
izontal to start auger. Paddle should rotate freely without "sticking."
3. Inspect for secure mounting and wiring of mercury switches in terminal box on top auger paddle
switch shaft. Include check for defective mercury switch. When calling for grain, both mercury
switches should be closed and passing 120V to top auger contactor coil.
4. Verify closing of top auger contactor; check voltage on load side of contactor, power terminals 7, 8,
and 9 (3-phase). Inspect contactor for defective points or a burned out coil.
5. Inspect connections and check voltage applied to motor leads in motor junction box to determine if
motor is defective.
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