T-318
3
−
12
3.4.5 Arctic Mode
With arctic mode enabled (configuration variable CnF29
set to “In”), there will be a 30-minute time delay at
startup if the ambient is colder than -10.0
C (14
F).
When the START/STOP switch is placed in the “I” (ON)
position, the controller will energize the compressor
crankcase heater. Operation of the heater will warm the
oil and boil off any liquid refrigerant that may be present
in the crankcase.
If Pre-Trip is initiated during the 30 minute time period,
Pre-Trip will be allowed to run normally. Once Pre-Trip is
over, the controller will revert to its normal control mode
logic (refer to Table 3-4).
3.5 QUEST
−
CCPC
Compressor
−
Cycle Perishable Cooling (CCPC) is a
method of temperature control during steady
−
state
perishable cooling that cycles the compressor on and off
according to return air temperature.
To be eligible for steady
−
state control the unit must first
complete a “setpoint pulldown” phase and a “CCPC
pulldown” phase:
During setpoint pulldown supply air temperature is
controlled according to the unit’s nominal supply air
setpoint.
During CCPC pulldown the supply air temperature is
lowered somewhat relative to the nominal setpoint.
Evaporator fans are forced to operate at high speed.
Steady
−
state CCPC control maintains the same
lowered supply air temperature as was used during
CCPC pulldown. The compressor cycles on and off
according to return air high and low limits. Depending on
the fan mode of operation selected, the evaporator fans
may be programmed to run at low speed some or all of
the time according to the control logic.
3.6 CONTROLLER ALARMS
Alarm display is an independent controller software
function. If an operating parameter is outside of
expected range or a component does not return the
correct signals back to the controller, an alarm is
generated. A listing of the alarms is provided in
The alarm philosophy balances the protection of the
refrigeration unit and that of the refrigerated cargo. The
action taken when an error is detected always considers
the survival of the cargo. Rechecks are made to confirm
that an error actually exists.
Some alarms requiring compressor shutdown have
time delays before and after to try to keep the
compressor on line. An example is alarm code “LO,”
(low main voltage), when a voltage drop of over 25%
occurs, an indication is given on the display, but the unit
will continue to run.
An alarm is indicated by flashing an alarm code on the
display panel, and for some alarms, by the alarm light
illuminating.
When an Alarm Occurs:
a. The red alarm light will illuminate for “20 series”
alarms.
b. If a detectable problem is found to exist, its alarm
code will be alternately displayed with the set point on
the left display.
c. The user should scroll through the alarm list to deter-
mine what alarms exist or have existed. Alarms must
be diagnosed and corrected before the Alarm List can
be cleared.
To Display Alarm Codes:
a. While in the Default Display mode, press the ALARM
LIST key. This accesses the Alarm List Display Mode,
which displays any alarms archived in the Alarm
Queue.
b. The alarm queue stores up to 16 alarms in the se-
quence in which they occurred. The user may scroll
through the list by depressing an ARROW key.
c. The left display will show “AL##,” where ## is the
alarm number sequentially in the queue.
d. The right display will show the actual alarm code.
“AA##” will display for an active alarm, where “##” is
the alarm code. Or “IA##” will display for an inactive
alarm.
e. “END” is displayed to indicate the end of the alarm list
if any alarms are active.
f. “CLEAr” is displayed if all alarms are inactive. The
alarm queue may than be cleared by pressing the EN-
TER key. The alarm list will clear and “
-----
” will
be displayed.
NOTE
AL26 is active when all of the sensors are not re-
sponding. Check the connector at the back of the
controller, if it is loose or unplugged, reconnect it.
Then run a pretrip test (P5) to clear AL26.
3.7 PRE
−
TRIP DIAGNOSTICS
Pre-trip diagnostics is an independent controller
function that will suspend normal refrigeration controller
activities and provide preprogrammed test routines.
The test routines include Auto Mode testing, which
automatically performs a pre
−
programmed sequence of
tests or Manual Mode testing, which allows the operator
to select and run any of the individual tests.
CAUTION
Pre-trip inspection should not be per-
formed with critical temperature cargoes in
the container.
CAUTION
When Pre-Trip key is pressed, dehumidific-
ation and bulb mode will be deactivated. At
the completion of Pre-Trip activity, dehu-
midification and bulb mode must be
reactivated.
