Carrier 50PG20-28 Controls, Start-Up, Operation, Service And Troubleshooting Instructions page 56

return a ir, o rstuck o pen e conomizer when t he ambient tempera-
ture islow.
Alert Code T140 (Loss of Charge) See Alert Tll0.
Alert Code T141 (Low Refrigerant Pressure) See Alert
T133.
Alert Code T142 (High Refrigerant Pressure) See Alert
T126.
Alert Codes T 143, T 144, T 145 (Failure to Pressurize)
Alert codes T143, T144, and T145 are for circuits A, B, and C,
respectively. These alerts occur when the compressor turns on
and the suction pressure does not drop 5 psig during the first
15 seconds and the condensing temperature does not rise 5 F
during the first minute. These alerts cause a strike for the
respective circuit. The alert resets automatically. The cause of
the alert is usually compressor wiring causing reverse rotation
or a faulty compressor.
Alert Code T153 (Real Time Clock Hardware Failure)
Time and date functions wilt not operate, such as local occu-
pancy schedules. The RTC clock chip on the MBB is not re-
sponding. Recovery is automatic but MBB board replacement
may be necessary. Cycling power to the control and reconfimar-
ing the time and date should be tried before board replacement.
Alarm Code A154 (Serial EEPROM Hardware Failure)
The unit will completely shut down. The serial EEPROM chip
on the MBB which stores the unit's conliguration is not
responding. Recovery is automatic but MBB board replace-
ment may be necessary. Cycling the power to the control
should be tried before board replacement.
Alert Code T 155 (Serial EEPROM Storage Failure Error)
Configuration data in the serial EEPROM chip can not be veri-
fied. Recovery is automatic but MBB board replacement may
be necessary. Cycling power to the control and reconfimaring
the control points should be tried before board replacement.
Alarm Code A156 (Critical Serial EEPROM Storage Fail
Error I The unit will completely shut do,a_. Critical conligu-
ration data in the serial EEPROM chip can not be verified.
Recovery is automatic but MBB board replacement may be
necessary. Cycling power to the control and reconfimlring the
critical control points should be tried before board replacement.
Check the conlimarations for the following critical points:
Cot_figuration _'OOL ---_?¢i (IR (Number of Circuits)
(bnfiguration _'OOL---_N.A (Compressors on Circuit A)
(bnfiguration_'OOL _OFC_OFC.3 (OFC.3 Enable,
CCH Disable)
(bnfiguration---_HMZR---_REHT (Humidimizer Equipped)
(bnfigumtion ---_HMZR---_RH.FN (Reheat Fan Control)
Alarm Code A157 (A/D Hardware Failure) The unit will
completely shut do,a_. The analog to diNtal conversion chip
on the MBB has thited. Recovery is automatic but MBB board
replacement may be necessary. Cycling power to the control
should be tried before board replacelnent.
Alarm Codes A163, A164, A165 (Circuit Failure) Alarm
codes A163, A164, and A165 are for circuits A, B, and C,
respectively. These alarms occur when a circuit has 3 strikes.
Use the Serolling Marquee display to reset the alarm. Investi-
gate the alarm that caused the strikes to occur.
Alert Code T179 (Com. Failure with ECB) This alert oc-
curs when the MBB cannot communicate with the ECB. This
is usually caused by a wiring problem. Investigate using the
Low Voltage Schematic.
Alert Code T180 (Com. Failure with Economizer Actuator)
This alert occurs when the MBB cannot communicate with the
Belimo Actuator. This is usually caused by a wiring problem.
Investigate using the Low Voltage Schematic.
Alarm Code A404 (Fire Shutdo,am) This alarm occurs
when the shutdown input is either open or closed depeMing
upon its conlimaration. This alarm is usually caused by an aux-
iliary device that is trying to shut down the unit, e.g., smoke de-
tector. The confimaration for this switch input can be tbund at
variable Configuration--_U?VlT--_FS.SVK Verify that the con-
figmration is set correct, verify the wiring and auxiliary device.
This alarm resets automatically.
Alert Code T408 (Dirty Air Filter) This alert occurs when
the Filter Status switch senses a plugged filter tbr 120 continuous
seconds after the indoor tim has been running tbr 10 seconds.
Because the Dirty Air Filter switch can be configured normally
opened or closed, the switch might be open or closed. The
conliguration for this switch input can be tbund at variable
Configurotion---_U?vlT---_FL.SV_
Verify that the configuration
is set correct, verify the wiring and tilter slams switch. The hose
should be connected to the low side of the switch. This alert re-
sets automatically.
Alert Code T409 (Fan Status Switch On, Fan Contactor
Of*) This alarm occurs when the tan status switch has
sensed that the indoor fan has been on for 10 seconds and the
indoor fan feedback has detennined that the indoor thn should
be oil" Because the Fan Stares switch can be conlimared
nonnalty opened or closed, the switch might be open or closed.
The configuration for this switch input can be found at
Configuration--_UNIT--_FN.SW. Verify that the configuration
is set correctly. Verify the wiring and tan stares switch. The
hose should be connected to the high side of the switch. If the
IDF is configured to shut down the unit when this alarm occurs
(Configuration---_U?vlT--->IDEF = YES), then this alarm can
only be reset manually and the unit is shut do,a_. If the IDF is
not configured to shut the unit down when this alarm occurs
(Configuration---_U?vlT---_IDEF = NO), then this alarm resets
automatically and no specific control action is taken.
Alert Code T409 (Fan Status Switch Off, Fan Contactor
On) This alert occurs when the thn status switch has sensed
that the indoor tan has been off for 10 seconds and the indoor
fan feedback has determined that the indoor fma should be on.
Because the Fan Status switch can be configured nonnalty
opened or closed, the switch might be open or closed. The
conli_ration for this switch input can be found at (bnfigura-
tion--_UNIT---_FN.SV_ Verify that the configuration is set
correctly. Verify the wiring mad tan status switch. The hose
should be connected to the high side of the switch. If the IDF is
conligured to shut down the unit down when this alert occurs
(Configuration---_U?vlT--->IDEF = YES), then this alarm can
only be reset manually and the unit is shut down. If the IDF is
not conlimared to shut the unit down when this alert occurs
(Configuration---_U?vlT--+IDEF = NO), then this alert resets
automatically and no specific control action is taken.
Alert Code T410 (R-W1 Jmnper Not Installed in Spare
Temp Mode) This alert occurs when the control mode is
Space Temperature mode via Auto Select or Space Temp
Select yet there is no power to W1. Verify that space tempera-
rare mode is the desired mode or add jumper bevween R mad
W1. This alert resets automatically.
Alert Code T410 (R-W1 Jmnper Must be Installed to Run
Heat in Selaqce Test) This alert occurs when a request for a
heat output has occurred yet the Wl input is not high. A jumper
must be installed bewveen R and W1 when trying to test heat in
Sel_qce Test. The alert will clear when Sel_qce Test is exited or
if another Sela_iceTest mode is selected. Remove jumper when
done using Service Test it"the unit is operating with a thermo-
stat. The jumper should only be left in place if the unit is oper-
ating with a space temperature probe.
Alert Code T411 (Y2 without Y1) This alert occurs in
Thermostat mode when Y2 is energized and Y1 is not. Verify
thermostat and thermostat wiring. When Y2 rams On, the soft-
ware will behave as if Y1 and Y2 are both On. When Y2 turns
Oil; the sot_vare will behave as if Y1 and Y2 are both Off'.
This alert resets automatically when Y1 is mined On.
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