TM 9-6115-729-24
0003
WINTERIZATION KIT (FIGURE FO-1, SHEET 6)
There are two components of the winterization kit (Figure 14). One is the LCD display heaters and the other is
the fuel-fired coolant water heater and pump. The LCD display heater consists of HTR1 and HTR2. These
heaters receive power from one of two directions. There is a thermostatic switch (TS) in the control panel that
closes when the temperature falls below -20F 10F (-28.9C 5.6C). This switch applies +24 Vdc power to
HTR1 and HTR2 in order to keep the liquid crystal displays (LCD) in the GSC and DVR from freezing. Note that
this power is only available when the ECS is NOT in OFF. There is also a connection to the winterization control
box that will apply power to these resistors any time the winterization system is turned on at the control panel.
The second component of the winterization kit is a fuel-fired coolant water heater and pump. The heater burns
fuel from the main fuel tank in order to heat the coolant. The coolant is circulated through the engine in order to
prevent it from freezing. When the fuel-fired heater is turned on, an internal combustion blower starts, the water
pump begins circulating coolant, and the preheating phase of the glow plug is started. After approximately 60
seconds, the heater fuel pump starts to add fuel to the combustion chamber. The fuel/air mixture ignites. The
speed of the air fan increases as well as the fuel pump speed through four stages. Low, Med, High, and Power in
order to bring the combustion chamber up to operating temperature.
The glow plug protection circuit has a flame detector, which will restart the heater if no flame is detected. If no
flame is detected twice, the heater is shut down and power must be cycled OFF and back ON to restart. The
heater continues to operate in the Power mode until either the temperature exceeds 162F (72C) or 2 hours has
elapsed (maximum time allowed in Power mode). The heater then switches between the four modes, as required
based on temperature of the coolant (which relates to heat necessary to raise the temperature of the coolant).
