Challenger Terra Gator 3244 Chassis. Manual - part 108

HVAC

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Fresh Air

FIG. 17: Fresh air flow

The fresh air flow comes from the blower which is

located underneath the seat. The air flow goes

underneath the cab floor mat to the dashboard console.

Inside the dashboard goes the air flow through the air

gates into the cab.

The arrows in the figure shows the air flow.

Fresh Air Filter

FIG. 18: Fresh Air Filter

Fresh air is drawn through cab filter (1) located above

windshield. Filter collects dust particles from air, then

travels down rear cab supports to HVAC unit.

Maintenance for Air Filter (Cab)

Maintenance for Cab Air Filter

If necessary, filter should be cleaned or replaced.

Ensure tight seal on filter so dust is not drawn into

system.

Refer to Operation and Maintenance Manual, Air Filter

(Cab) - Clean/Replace for additional information about

inspecting and cleaning filter.

Recirculation

Recirculated Air Filter

FIG. 19: Recirculated Air Filter

Recirculated air is drawn through recirculation cab filter

(1) located behind operator seat. Filter collects dust

particles from air. HVAC unit is directly behind filter.

If necessary, filter should be cleaned, inspected or

replaced.

Refer to the Operation and Maintenance Manual, Air

Filter (Cab Recirculation) - Clean/Replace for additional

information about inspecting and cleaning filter.

FIG. 17

q000262s

FIG. 18

M121103001

1

FIG. 19

M12110315

1

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HVAC

Charcoal Air Filter

FIG. 20: Charcoal Air Filter

IMPORTANT: To maintain proper cab pressurization,

baffle must be in the fully raised position when

used with charcoal filter. When used with a

standard cab filter, baffle must be in fully

lowered.

Charcoal filter (1) is used in conjunction with a baffle on

cab air filter cover.

Life of filter is affected by environmental conditions and

should be replaced when odor, taste or other

symptoms of contamination are detected. Replace the

filter at least every 1000 hours / annully

Head, Foot and Defrost

FIG. 21: Airflow to Vents

Vents on front console direct cab airflow toward

operator's top, sides and feet.

Rear posts for ROPS are incorporated with air ducting.

Operator has control of all vents, however, a motorized

damper controls airflow for front console. Damper is

automatically controlled by control module.

MOTOR (AIR CONDITIONING BLOWER)

FIG. 22: Blower Components

Fan (1) is used to circulate air for HVAC system and is

located in HVAC unit (3). Motor (2) drives fan.

Rotation of motor is clockwise.

Overpressure blower

Inside the cab of Terra Gator is always a overpressure

to keep the air inside the cab clean. The blower which

prevent the overpressure is located underneath the

operator’s seat.

FIG. 20

q000299s

1

FIG. 21

q000262s

FIG. 22

1

2

3

1

M12110315

2

HVAC

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627333-A  

Automatic Temperature Control (Fan)

Auto Mode

Fan speed is system determined based on difference

between setpoint and actual cab temperature. A large

difference in temperature results with faster fan speed.

Heating or cooling occurs if cab is too hot or cold. Fan

speed is held at a minimum when cab is heating or

cooling quickly and overshoots setpoint temperature.

In automatic mode, fan speed is limited by temperature

of outlet duct. If temperature of duct is less than 22

degrees C (72 degrees F), fan speed is limited to low

speed. Fan speed gradually increases as temperature

of duct increases. This continues until temperature of

duct reaches 35 degrees C (95 degrees F). This limit is

disabled if a duct temperature sensor error occurs. In

automatic mode, all changes in fan speed are gradual.

Manual Mode

Fan speed directly corresponds to fan speed control.

Control is a potentiometer allowing infinite adjustment.

Initial fan speed on start-up gradually increases to

desired fan speed.

Manual Fan Control

Manual fan speed switch provides operator with five

speed selections, including off. Fan speed is

independent.

SPEED CONTROL

Automatic Fan Speed Control

Speed controller consists of control panel and main

control module. Fan speed rotary control must be in

auto to allow automatic control of fan.

Speed controller for fan regulates amount of voltage

supplied to blower motor and operates in a linear mode

on ground side of blower motor. 

Speed controller for fan also provides thermal

protection if there is a short circuit. This protection is

also provided for a stalled motor or any other condition

causing excessive temperature in heat sink. Limit of

output current is proportional to sensed output voltage

causing current to feedback if there is a stalled motor or

a short circuit to Vbatt. Output faults cause temperature

in heat sink to rise. Insufficient airflow also causes

temperature in heat sink to rise. Thermal protection is a

two-stage process. When temperature in heat sink is

greater than approximately 70 degrees C (158 degrees

F), thermal protection causes output to attempt

maximum output voltage. If temperature in heat sink

continues to rise above approximately 105 degrees C

(221 degrees F), output turns off. Output turns on when

temperature in heat sink lowers to approximately 70

degrees C (158 degrees F).

Manual Mode Fan Speed Control

Fan speed directly corresponds to fan speed control. In

automatic or manual mode, initial fan speed on start-up

gradually increases to desired speed.

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HVAC

ACTUATOR MOTOR (DAMPER)

FIG. 23: Actuator Motor Schematic

Actuator Motor (1)

Inside Actuator (2)

2-Pin Connector (3)

Actuator motor is used in one position on HVAC system

to control a damper for airflow of defrost for front

window. 

NOTE: Refer to table in Systems Operation, Control

Module for details on operation of actuators.

FIG. 23

N011803012

1

3

2