Carrier SUPRA 850Mt Operation And Service Manual page 29

Manual defrost key
The MANUAL DEFROST key places the
unit in a defrost cycle. Under most
conditions it is not necessary to defrost
the unit manually as this is done
automatically with the air switch or the
defrost timer. Manual defrost may
become
accumulated on the evaporator coil
during frequent door openings in humid
environments.
Buzzer Off key
The BUZZER OFF key temporarily turns
off the FAULT ALARM buzzer. The red
light "Fault alarm" remains illuminated on
the command cab.
Standby key
The STANDBY key places the unit in
Standby (or electric) mode when the
previous mode of operation has been
Road.
Pretrip Check key
Not used.
Auto Start/Stop Continuous key
The AUTO- -START/STOP key toggles
the unit operating mode between
Auto--Start/Stop and continuous run.
When the unit is set for Auto--Start/Stop
operation, the unit will run until the box
temperature reaches set- - point and then
cycle off (after theminimum run time has
been met) until further cooling or heating
is necessary. When in the continuous
mode, the unit will cycle between heat
and cool as required to maintain the set
temperature in the body. If the setpoint is
below -12
_
it will run continuously in low speed cool.
Unit Data key
This key scrolls the display through the
i
various operating condition displays,
engine temperature or battery voltage, for
example. A more complete description of
the function is found later in this chapter.
Compartment 1 ON/OFF switch
necessary due to
C(10 F) the unit will not heat,
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Compartment 2 ON/OFF switch
ice
Compartment 3 ON/OFF switch
16. Fault Alarm led : illuminates when an alarm is
detected.
2.8.3 Switches and controls
Components required for monitoring and controlling
the diesel engine--refrigeration system are located in the
electrical box.
Run/Stop switch
RUN
STOP
2.8.4 Setpoint
Setpoints of --30
be entered via keypad. The controller always retains the
last entered setpoint in memory. If no setpoint is in
memory (i.e., on initial startup), the controller shall lock out
the run relay and flash "SP" on the left hand display until
a valid setpoint is entered.
The setpoint may be changed up or down in whole
numbers until the desired setpoint is displayed. The dis-
play will flash to indicate that the setpoint reading being
displayed is a non-entered value. Each time the up/down
arrow key is pressed, the 5 second display timer will bere-
set.
Depressing the enter key will cause the new dis-
played setpoint value to become active. If the display is
flashing and the new value is not entered, after 5 se-
conds of no keypad activity, the display will revert back
to the active setpoint.
2-17
when switched to (I) the unit and
compartment 1 will start in the
operating mode last entered (cooling
or heating).
when switched to (I) the unit and
compartment 2 will start in the
operating mode last entered (cooling
or heating).
when switched to (I) the unit and
compartment 3 will start in the
operating mode last entered (cooling
or heating).
When placed in RUN position, this
switch provides power
microprocessor.
To stop the unit or remove power from
the microprocessor, move the Run/Stop
switch to STOP.
C to +30 C (--22
_ _ _
to the
F to +86 F) may
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