TM 5-2420-230-10
a. A/C Controls Introduction.
The temperature in the IHMEE cab is fully controlled by
a compact, ceiling-mounted unit, which provides 8 hp
(6 kW) of cooling and 5 hp (4 kW) of heating. The unit
also provides prefiltered make-up air to the cab.
To prevent the possibility of damaging the
air-conditioning unit is switched OFF prior to
starting the engine. Failure to comply may result in
damage to equipment.
The controls of the air-conditioning unit are shown in the
enlarged view of the control panel:
PULL FOR HEAT control
A/C fan speed switch (only operative when A/C
or FANS are selected)
A/C selector switch
b. Cab Cooling.
Cooling the cab is achieved by selecting A/C on the selector switch and pushing in on the PULL FOR HEAT control.
This sets the temperature control to the coldest setting, and sets the fan speed to H (High). Once the desired comfort
level is reached, fan speed can be reduced to M (Medium) or L (Low) to maintain a comfortable temperature in the cab.
NOTE
The cab heater utilizes engine coolant as a heat source. Therefore, the heater reaches maximum
efficiency only when the engine has reached normal operating temperature.
To heat the cab, pull the PULL FOR HEAT control out, select either A/C or FANS, and turn fan speed to H (High). As
soon as the cab has reached the desired temperature, the temperature and the fan speed controls can be progressively
reduced to maintain a comfortable temperature in the cab.
d. Cab Defrosting.
To defrost the cab, pull the PULL FOR HEAT control partially out, select A/C, and set fan speed to H (High). The
dehumidifier in the air-conditioner unit removes excess moisture from the cab. When the windows have been defrosted,
the fan speed can be reduced to M (Medium) or L (Low) to maintain clear vision through the cab glass.
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