Carrier T-326 User Manual

Page 12

T--326

There will be some applications where the switch mounting plate,

thermostat and fan speed switch are mounted in the drivers area

without the control panel housing.
On other applications the vehicle manufacturer (OEM) will supply

different type controls for the air conditioning system. Refer to OEM

technical manual for operating instructions.
2.2.1 Fan Speed Switch (three speed or variable)
Turning this switch clockwise will energize the evaporator and

condenser fan motors. The compressor clutch will also be

energized if the thermostat calls for cooling (see thermostat control

operation).
Three Speed -- The standard fan speed switch has four settings,

Off (0), Low (1), Medium (2), and High (3) speed operation. This

switch controls the operation of the system and the evaporator

blower(s) by energizing the appropriate circuits and relays located

on the electrical control panel.
Variable Speed -- Certain applications may be fitted with a variable

speed control switch instead of the standard three speed switch.

This switch controls the speed of the evaporator motors by varying

the supply voltage.
2.2.2 Thermostat Control
The thermostat controls the temperature within the passenger

compartment by switching system components on and off.
Rotate the potentiometer switch knob to the right (clockwise) for

maximum cooling. Rotate the potentiometer switch knob to the left

(counterclockwise) for less cooling.
2.3 DRIVER’S CONTROL PANEL -- FLORIDA (TEMPCON)
This control panel (See Figure 2-2) is normally used in school

buses located within the state of Florida, but not limited to that area.

This controller is wired to an electrical control board.
The controller consists of:
a. ON/OFF Switch
b. Fan Speed Switch
c. Potentiometer
d. In--Line Fuse (Behind Controller)

2.3.1 ON/OFF Switch
Power is supplied to the controller, through an in--line fuse (see

Figure 2-3) from a 12 VDC ignition source originating from the

vehicle. The controller will not operate until the ignition switch is

activated.