Carrier 68G5-105 Series - Page 32

3-4T -312
Table 3-3. Driver Display Panel Alarm Message Definition - Continued
ALARM
NO.
TITLE CAUSE REMEDY MICROPROCESSOR RESPONSE
A27 Low Pressure
Shutdown
Low suction pressure. Check cause of low
suction pressure. (Re-
fer to section 3.3.3.)
If alarm has been activated three
times in 30-minutes, the clutch will
be de-energized until the alarm is
de-activated.
If alarm has been activated three
times in 30-minutes, de-energizes
the rest of the system unless heat is
required. Runs the main evaporator
fan at low speed until alarm is reset.
A28 High Voltage Power 12 vdc source
voltage is greater than
17 vdc.
Check, repair or re-
place alternator.
All microprocessor outputs are de-
energized.
A29 Low Voltage Power 12 vdc source
voltage is less than 10
vdc.
Repair or replace
wiring or alternator.
All microprocessor outputs are de-
energized.
A31 EEPROM Memory failure. Replace main micro-
processor at next ser-
vice stop.
Modifies out of range values to their
default values.
Table 3-4. Parameter Codes
CODE CODE NAME DESCRIPTION
P5 Suction Pressure This value is the suction pressure measured by the suction pressure transduc-
er. If the sensor is shorted it will display CL If it is open circuited it will display
OP. NOTE: This value is not updated, it is the value at the time that the code
is accessed.
P6 Discharge Pressure This value is the discharge pressure measured by the discharge pressure
transducer. If the sensor is shorted it will display “CL” and if it is open circuited
it will display “OP”. NOTE: This value is not updated, it is the value at the time
that the code is accessed.
P20 Compressor Hours
High
This is the number of hours of operation that the compressor has run with the
clutch energized. The reading is in thousands.
P21 Compressor Hours
Low
This is the number of hours of operation that the compressor has run with the
clutch energized. The reading is in hundreds, tens and ones.
P22 Evaporator Hours
High
This is the number (in thousands) of hours of operation with the evaporator
fans energized.
P23 Evaporator Hours
Low
This is the number (in hundreds, tens and ones) of hours of operation with the
evaporator fans energized.
P30
Controller So
f
tware
This is the software version of the logic board. The first two digits of the soft-
ware revision are displayed. Ex. Revision XXYY XX is displayed after P30.
P31
C
o
n
t
r
o
l
l
e
r
S
o
f
t
w
a
r
e
Version
This is the software version of the logic board. The second two digits of the
software revision are displayed. Ex. Revision XXYY YY is displayed after P31.