Common Diagnostic Issues
Listed below are common issues that may occur while operating your Mathews Company grain dryer along with suggestions on what to do.
Dryer will not reach operating temperature, or it reaches it slowly.
Low gas pressure. Increases gas pressure on the main gas regulatory.
Check for water in the gas train by opening the drain valve.
Make sure the dryer is completely full of grain by entering the heat plenum chamber and looking for daylight in one of the grain columns.
Make sure that the gas butterfly valve is being driven wide open by the modutrol motor. If not, check the motor or motor linkage. Also check to make sure that there is not a block within the gas piping. There should be 10 pounds on the primary regulator and 1 to 2 pounds on the secondary.
Ensure the max % valve opening on the Pinnacle 20|20 Control is not set too low.
Blower motor(s) will not start.
Check that the fan circuit breaker has not tripped and that the fan button is pressed on the HMI.
Verify closing of the fan motor contactor. Check voltage on the load side of the contactor.
Inspect the contactor for defective contact or a burned out coil.
Inspect connections, and check voltage applied to the motor leads to determine if the motor is defective. If the motor starts slowly, check for low voltage during starting due to excessive voltage drop in power supply wiring.
If the motor starts slowly, check for low voltage during starting due to excessive voltage drop in power supply wiring.
Burner will not fire.
Check gas supply for possible obstruction or closed valves. Refill tank; replace or repair parts as required.
Inspect gas solenoid valves for defective coils or improper wiring. Replace the valve or coil if the valve will not open with proper voltage applied (115 volts).
Ensure initial % valve opening is properly set.
Burner will not fire, but gauge shows gas pressure.
Check that the igniter is properly gapped and has a strong spark.
Inspect the porcelain and electrodes for damage or cracking. Clean or replace if necessary.
Machine does not have chassis ground.
Check solenoids for proper operation.
Ensure initial % valve opening is properly set.
Uneven drying, some kernels appear brown while others are under dried. Uneven heat exiting from dryer columns.
Check plenum temperature setting. Some varieties of grain are more sensitive to higher operating temperatures. It may be necessary to lower the plenum operating temperature to accommodate this.
Grain is not moving through columns.
Check the dryer for fine material buildup inside the columns.
Avoid leaving the dryer columns full for long periods at a time (2-3 days) while not operating the dryer, or during rainy weather.
Empty the dryer and clean regularly. Do not allow fine material to gather in the plenum chamber.
Difficult lighting the burner
Fan must be ON to achieve air pressure light.
Ignition button is pressed on HMI. This applies 24 VAC at L1 (0 volts at L2 Neutral) of the ignition board.
After pre-purge time, the ignition board should power out 24 VAC at V1 (V2 neutral) for a trial ignition period to eliminates the gas valve light and gas valve light. The ignition trial time is 7 seconds. If the trial is not successful, voltage outputs stops.
Check the gas solenoid operation by listening for a click/snap or feeling the vibration as they open. If the solenoid doesn’t open, check the wiring and coil for damage, bad connections, etc.
Check the spark plug (igniter) for spark. Check the high voltage wire for damage, good connections.
Replace the ignition board.
Ensure initial % valve opening is properly set.
The burner lights but does not stay on.
(NOTE: This is most likely due to the flame sensing)
Ensure flame sense probe is located in the flame.
Inspect the sense wire for damage and for loose or wet connections.
Check that sense wire is routed separately from the high voltage ignition wire.
Check the ignition board (B.GND) is grounded separately from all other connections. Sharing a ground connection can cause problems.
Clean sense probe with fine steel wool. Burner may have to be grounded at the burner body directly to the burner housing
Burner may have to be grounded at the burner body directly to the burner housing
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