The Burner Control Cabinet and associated sub-panel, shown below, house all of the components to safely operate the fan and burner which includes an air pressure switch, high limit switch, and an ignition board or Flame Controller, Amplifier, Ignition Transformer and Programmer Module if upgraded from an ignition board. The cabinet is mounted near the fan and burner for ease of access and/or troubleshooting purposes. There is one Burner Control Cabinet per burner and are different for each dryer series. As previously mentioned, all dryers come standard with the Fire Eye (Flame Controller, Amplifier, Ignition Transformer and Programmer Module) except for next generation Legacy dryers in which the Fireye is an option and the Fenwal Ignition board is standard. Shown below is the burner box housing the Fireye Ignition system.
The High Limit Switch utilizes a capillary bulb to sense an over-temperature condition in the plenum which will cause the dryer to shutdown. The high limit setpoint is adjustable on the switch and should be set approximately 40 deg F higher than the plenum temperature setpoint.
The purpose of the Air Pressure Switch is to prove airflow from the fan for safe operation of the burner. The air pressure switch is adjustable and should be set once the dryer is full of grain. Adjustment of the switch is done in the burner control cabinet and indication of reaching the air pressure switch's setpoint is indicated by the illumination of the green light on the outside of the burner control cabinet.
The Ignition Transformer supplies the high voltage to the spark plug to ignite the burner.
The Flame Controller is a compact, microprocessor base, modular burner management system designed to provide automatic ignition and continuous flame monitoring.
The amplifier module provides flame scanning capabilities using any of the Fireye standard scanners. Measuring of flame signal strength is available on this module. Insert DC voltmeter leads in the two test jacks labeled “ NORMAL DC TEST VOLTAGE 4.0 TO 5.5 VDC”. Red for positive (+) polarity and black for minus (-) polarity. A DC voltage reading of 4.0 to 10 volts for all amplifier types should be obtained when the control is detecting flame and 0 volts when no flame is present. Wildly fluctuating readings are an indication of an unstable flame or flame sensor requiring maintenance.
This module, when used with the Fireye Control, provide diagnostics through LED's and alpha-numeric display.
The Fenwal Ignition Board is a 120 Volt board and controls the overall operation of the burner by supplying high voltage from the coil to the spark plug to ignite the burner, sending signals to open/close the gas valves, and continuously monitoring the presence of a flame for safe and reliable operation
