TM 10-4520-262-12&P 0003 00
Placing the ON/OFF switch of the in-tent controller in the ON position sends a signal to the power control
assembly (1) as well as to the heater control assembly (2) energizing the system. At this point the heater
on/on-hold advisory light (3) on the in-tent controller will illuminate, indicating the heater has begun
operation. After a wait of five seconds a visual audible function check of the in-tent controller is made.
The battery charging light, battery charged light and system fault light are illuminated with the audible
tone for approximately two seconds.
A battery pack (4) is used to supply power to the heater assembly (1) and facilitate burner ignition until
the thermoelectric generator (TEG) (5) begins generating power. The power drawn from the batteries is
replaced by the TEG while the heater delivers heat to the shelter.
Once power is applied to the system, the heater control assembly (2) sends a signal to the fuel solenoid
valve assembly (6), opening the valve and allowing fuel to flow through the sediment strainer (7) to the
float assembly (8). Power is supplied to preheat the glow plug (12). Fuel is then pumped in short pulsating
bursts by the fuel pump (9) to the burner head assembly (10), where it is vaporized from the heat of the
Air that is drawn through the combustion air inlet is mixed with the hot vaporized fuel providing oxygen for
flame ignition. Heat produced from this combustion is converted to electrical power by the thermoelectric
generator (TEG) (5). The TEG provides electricity which is used to recharge the batteries. When the
batteries are charging, the battery charging advisory light (14) on the in-tent controller assembly
illuminates. The heater continues to run as the batteries recharge.
When the batteries (4) are fully recharged, the battery charged advisory light (15) on the in-tent
controller assembly illuminates and the battery charging light (14) is extinguished. At a specified
temperature measured at the TEG, the heated air blower assembly (16) is engaged and cold air is drawn
from the shelter through the air supply duct (17) and forced through the heat exchanger (18) at the outlet
end of the heater. The shelter air is heated and forced out the air return duct (19) into the shelter as
As heated air is supplied to the shelter, the temperature inside the shelter rises. This temperature is
monitored by a sensor (20) on the in-tent controller assembly. When the shelter temperature reaches the
value set on the lower/higher control (21) on the in-tent controller assembly, a signal is sent to the
heater. The fuel pump and combustion air are slowed down reducing the heat supplied to the shelter. Air
continues to circulate through the shelter via the heated air blower assembly (16) and the At Setpoint
advisory light (22) illuminates.
If the shelter temperature exceeds approximately 90 degrees F, the in-tent controller will shut off the
heater. The heater on/ on hold light will remain on. When the shelter cools the heater will begin a normal
Heater operation is terminated by switching the ON/OFF switch (23) on the in-tent controller to the OFF
position. The fuel solenoid valve (6) is closed and all fuel flow to the burner assembly (10) ceases. When
all advisory lights are extinguished, the heater is shut down and can be moved or left in place for another