70
Table 49 — Alarm Codes (cont)
LEGEND
PREFIX
CODE
SUFFIX
CODE
ALARM
NUMBER
ALARM DESCRIPTION
REASON FOR ALARM
ACTION TAKEN
BY CONTROL
RESET
TYPE
PROBABLE CAUSE
Co
A1
53
Loss of communication with
Compressor Board A
No communication
with CPM board
Affected
compressor shut
down
Automatic
Wrong CPM address,
wrong unit configura-
tion, wiring error, power
loss, failed
CPM board
B1
54
Loss of communication with
Compressor Board B
E1
56
Loss of communication with
EXV Board 1
No communication with
EXV board
Affected
compressor
shut down
Automatic
Wrong EXV board
address, wrong unit
configuration, wiring
error, power loss,
failed EXV board
E2
57
Loss of communication with
EXV Board 2
03
64
Loss of communication with
Energy Management Board
No communication with
EMM board
Disable or not allow
EMM functions
3 step and 4-20 mA
and space tempera-
ture reset, occu-
pancy override and
ice build)
Automatic
Wrong board
address, wrong unit
configuration, wiring
error, power loss to
module, failed module
05
66
Loss of communication with
AUX Board 6
No communication
with MLV/COND Board
Unit shut down or
not allowed to start
Automatic
Wrong board
address, wrong unit
configuration, wiring
error, power loss to
module, failed module
P
01
67
Cooler Freeze Protection
Entering or leaving therm-
istor sensed a tempera-
ture at or below freeze
point
Unit shut down or
not allowed to start
Automatic, first
occurrence in
24 hours;
manual if
multiple alarms
within 24 hours
Faulty thermistor, faulty
wiring, low water flow,
low loop volume, fouled
cooler, or freeze
conditions
02
68
Condenser Freeze Protection
Circuit A
—
None
Automatic
Configuration error
03
69
Condenser Freeze Protection
Circuit B
05
71
Circuit A Low Suction
Temperature
Low saturated suction
temperatures detected for
a period of time
Circuit shut down
Automatic, first
occurrence in
24 hours;
manual if
multiple alarms
within 24 hours
Faulty thermistor, faulty
wiring, low water flow,
low loop volume, fouled
cooler, or freeze
conditions
06
72
Circuit B Low Suction
Temperature
08
74
Circuit A High Suction
Superheat
EXV>98%,
suction superheat > 30 F,
and SST<MOP for more
than 5 minutes
Circuit shut down
Manual
Faulty transducer,
faulty wiring, faulty
thermistor, faulty EXV,
low refrigerant charge,
plugged or restricted
liquid line
09
75
Circuit B High Suction
Superheat
CCN
—
Carrier Comfort Network
®
MLV
—
Minimum Load Valve
CPM
—
Compressor Protection Module
MOP —
Maximum Operating Pressure
EMM
—
Energy Management Module
MTA
—
Must Trip Amps
EWT
—
Entering Water Temperature
SST
—
Saturated Suction Temperature
EXV
—
Electronic Expansion Valve
UL
—
Underwriters Laboratories
HPS
—
High Pressure Switch