Carrier X4 7300 Operation & Service Manual page 66

FUNCTION
TEMP CONTROL RETURN AIR
SUPPLY AIR
OUT OF RANGE Metric English
ALARM
OFF OFF
2°C
3°C
4°C
AUTOFRESH AIR CLOSED
OPEN
CFM CONTROL
AUTOFRESH AIR 5 To 50 CFM (in 5 CFM
CONTROL increments)
25 CFM
Time and Temperature values that control Start-Stop Operation are set in this section.
The system may be configured so that:
1. the same settings apply to any setpoint = "Together" or
2. the settings are different, depending on whether the setpoint is in the perishable range or in the frozen
range = "Separate".
• If "together" is configured, there will be six settings with only the sixth applicable to just frozen range.
• If "Separate" is configured there will be eleven settings five labeled perishable and six labeled frozen.
MINIMUM RUN 4MINS
TIME:
TO
60MINS (in 1 minute
increments)
MINIMUM OFF 10 to 90MINS (in 1
TIME: minute increments)
30 MINS
Table 3–2 Functional Parameters
PARAMETER
SELECTIONS
The evaporator has both a Return Air Sensor and a Supply Air
Sensor.
RETURN AIR = With this setting the unit will operate so that
the return air (air entering the evaporator) will be controlled to
setpoint. Return air temperature is generally considered to be
a good sampling of the actual product temperature.
SUPPLY AIR = The unit will operate so that the supply air (air
leaving the evaporator) will be controlled to setpoint whenev-
er the setpoint is in the perishable range (greater than 10.4°F
(-12°C). When the setpoint is in the frozen range the unit will
control the return air as described in the preceding Return Air
choice.
The value entered here is the number of degrees away from
setpoint the temperature may drift before it is considered
"Out-Of-Range" and the configured alarm or alarm and shut-
4°F
down action will be activated.
5°F
Refer to Alarm 00053 for more information.
7°F
Closed = AutoFresh Air Exchange assembly will be closed.
Open = Assembly will be open if the engine is running and the
setpoint is greater than 28.0°F (-2.22°C).
CFM Control = Assembly will be cycled open and closed over
a 20 minute time period. The length of time the assembly is
opened or closed is based on the Auto Fresh Air Control
Functional Parameter.
The CFM CONTROL will only be active if the engine is run-
ning and the setpoint is greater than 28.0°F (-2.22°C).
When CFM Control is selected, this setting is used to set the
amount of air to be exchanged during each 20 minute cycle.
START-STOP SETTINGS
This determines the minimum run time for perishable/frozen
setpoints in Start-Stop Operation.
This determines the minimum off time for perishable/frozen
setpoints in Start-Stop Operation.
3–21
DESCRIPTION
62-11637