TM 9-2540-205-24&P
IGNITION SYSTEM
Hupp MF510B, MF510C, MF60A-24V, MF60B-24V
IGNITOR RELAY (MF510B)-Monitors ignitor voltage, and adds a dropping resistor to the circuit if voltage ex-
ceeds 25 volts. It is an electromechanical device that extends igniter life.
POWER CONTROL (MF510C, MF60A-24V, MF60B-24V)-Atransistorized device that clamps the ignitor volt-
age to a safe level.
IGNITOR-Provides heat for lighting fuel/air mixture by glowing red-hot when energized.
PREHEATER-Warns the burner plate until it reaches the proper temperature for ignition to occur.
BURNER THERMOSTAT-Signals the valve relay to turn on the fuel regulator valve. Starts fuel flow as soon
as burner has reached proper temperature.
FLAME DETECTOR SWITCH-Turns off ignitor system once heater has started. It also connects the blower
motor directly to the 24-volt supply so it runs at full speed. It consists of a transfer-type microswitch operated
by a ceramic rod in a closed metal tube. Heat expands the tube, moving the rod away from the switch. When
the rod moves far enough, the switch operates.
A properly adjusted flame detector switch can prolong igniter life.
Misadjustment can cause a burned-out igniter or a heater that will not
start. Information on required adjustments is contained in the individ-
ual heater component paragraphs, referenced on page 2-39 (section
VI. Organizational Maintenance Procedures).
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CAUTION
