66
Table 26 — Alarm and Alert Codes (cont)
LEGEND
Table 27 — Example of Reading and Clearing Alarms
ALARM/
ALERT CODE
ALARM OR
ALERT DESCRIPTION WHY WAS THIS ALARM GENERATED? ACTION TAKEN
BY CONTROL
RESET
METHOD
T153 Alert Real Time Clock
Hardware Failure Internal clock on MBB fails
Occupancy schedule will not
be used. Unit defaults to
Local On mode.
Automatic when
correct clock
control restarts.
A154 Alarm Serial EEPROM
Hardware Failure Hardware failure with MBB Unit is unable to run. Manual
T155 Alert Serial EEPROM
Storage Failure Configuration/storage failure with MBB No action Manual
A156 Alarm Critical Serial EEPROM
Storage Failure Configuration/storage failure with MBB Unit is not allowed to run. Manual
A157 Alarm A/D Hardware Failure Hardware failure with peripheral device Unit is not allowed to run. Manual
A170 Alarm Loss of Communication
with CXB MBB loses communication with CXB CXB functions disabled Automatic
A173 Alarm Loss of Communication
with EMM MBB loses communication with EMM
4 to 20 mA temperature
reset disabled. Demand Limit
set to 100%. 4 to 20 mA
set point disabled.
Automatic
T174 Alert
4 to 20 mA Cooling Set
Point/Desired % Capacity
Input Failure
If configured with EMM and input less than
2 mA or greater than 22 mA
Set point function/%
capacity function disabled. Automatic
T176 Alert 4 to 20 mA Temperature
Reset Input Failure
If configured with EMM and input less than
2 mA or greater than 22 mA
Reset function disabled.
Unit returns to normal
set point control.
Automatic
T177 Alert 4 to 20 mA Demand Limit
Input Failure
If configured with EMM and input less than
2 mA or greater than 22 mA
Demand limit function
disabled. Unit returns to
100% demand limit control.
Automatic
A200 Alarm Fan Status
Switch 1 Open
Alarm is generated when fan status switch 1
is open when the unit is in an ON state Unit not allowed to start Automatic
T201 Alert
Fan Status Switch 1
is open with Dual TSTAT
configuration
Alert is generated when fan status switch 1
is open when Y1 or Y2 are closed Circuit A is not allowed to run Automatic
T202 Alert
Fan Status Switch 2
is open with Dual TSTAT
configuration
Alert is generated when fan status switch 1
is open when Y3 or Y4 are closed Circuit B is not allowed to run Automatic
T303 Alert Condenser Coil
Maintenance Due
Coil Service Countdown (C.L.DN) expired.
Complete condenser coil cleaning and enter ‘YES’
for Coil Maintenance Done (C.L.MN) item.
None Automatic
T500 Alert Current Sensor Board
A1 Failure
Alert occurs when CSB output
is a constant high value Compressor A1 shut down Automatic
T501 Alert Current Sensor Board
A2 Failure
Alert occurs when CSB output
is a constant high value Compressor A2 shut down Automatic
T502 Alert Current Sensor Board
A3 Failure
Alert occurs when CSB output
is a constant high value Compressor A3 shut down Automatic
T503 Alert Current Sensor Board
B1 Failure
Alert occurs when CSB output
is a constant high value Compressor B1 shut down Automatic
T504 Alert Current Sensor Board
B2 Failure
Alert occurs when CSB output
is a constant high value Compressor B2 shut down Automatic
T505 Alert Current Sensor Board
B3 Failure
Alert occurs when CSB output
is a constant high value Compressor B3 shut down Automatic
CCN — Carrier Comfort Network®LWT — Leaving Fluid Temperature
CSB — Current Sensor Board MBB — Main Base Board
CXB — Compressor Expansion Module SCT — Saturated Condensing Temperature
DTT — Discharge Temperature Thermistor SST — Saturated Suction Temperature
EEPROM — Electrically Erasable Programmable
Read-Only Memory
TSTAT — Thermostat
EMM — Energy Management Module
SUB-MODE KEYPAD
ENTRY ITEM ITEM EXPANSION COMMENT
CRNT AXXX or TXXX CURRENTLY ACTIVE ALARMS ACTIVE ALARMS (AXXX) OR
ALERTS (TXXX) DISPLAYED.
CRNT
RCRN
NO Use to clear active alarms/alerts
NO NO Flashes
YES Select YES
NO Alarms/alerts clear, YES changes to NO
ENTER
ESCAPE
ENTER
ENTER