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return air, or stuck open economizer when the ambient tempera-
ture is low.
Alert Code T140 (Loss of Charge) — See Alert T110.
Alert Code T141 (Low Refrigerant Pressure) — See Alert
T133.
Alert Code T142 (High Refrigerant Pressure) — See Alert
T126.
Alert Codes T143, T144, T145 (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 will 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 reconfigur-
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 configuration 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 T155 (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 reconfiguring
the control points should be tried before board replacement.
Alarm Code A156 (Critical Serial EEPROM Storage Fail
Error) — The unit will completely shut down. Critical configu-
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 reconfiguring the
critical control points should be tried before board replacement.
Check the configurations for the following critical points:
Configuration
→
COOL
→
N.CIR
(Number of Circuits)
Configuration
→
COOL
→
N.A
(Compressors on Circuit A)
Configuration
→
COOL
→
OFC
→
OFC.3
(OFC.3 Enable,
CCH Disable)
Configuration
→
HMZR
→
REHT
(Humidimizer Equipped)
Configuration
→
HMZR
→
RH.FN
(Reheat Fan Control)
Alarm Code A157 (A/D Hardware Failure) — The unit will
completely shut down. The analog to digital conversion chip
on the MBB has failed. Recovery is automatic but MBB board
replacement may be necessary. Cycling power to the control
should be tried before board replacement.
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 Scrolling 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 Shutdown) — This alarm occurs
when the shutdown input is either open or closed depending
upon its configuration. This alarm is usually caused by an aux-
iliary device that is trying to shut down the unit, e.g., smoke de-
tector. The configuration for this switch input can be found at
variable
Configuration
→
UNIT
→
FS.SW
. Verify that the con-
figuration 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 for 120 continuous
seconds after the indoor fan has been running for 10 seconds.
Because the Dirty Air Filter switch can be configured normally
opened or closed, the switch might be open or closed. The
configuration for this switch input can be found at variable
Configuration
→
UNIT
→
FL.SW
. Verify that the configuration
is set correct, verify the wiring and filter status 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
Off) — This alarm occurs when the fan status switch has
sensed that the indoor fan has been on for 10 seconds and the
indoor fan feedback has determined that the indoor fan should
be off. Because the Fan Status switch can be configured
normally 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 fan status 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
→
UNIT
→
IDF.F
= YES
), then this alarm can
only be reset manually and the unit is shut down. If the IDF is
not configured to shut the unit down when this alarm occurs
(C
onfiguration
→
UNIT
→
IDF.F
= 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 fan status switch has sensed
that the indoor fan has been off for 10 seconds and the indoor
fan feedback has determined that the indoor fan should be on.
Because the Fan Status switch can be configured normally
opened or closed, the switch might be open or closed. The
configuration for this switch input can be found at
Configura-
tion
→
UNIT
→
FN.SW
. Verify that the configuration is set
correctly. Verify the wiring and fan status switch. The hose
should be connected to the high side of the switch. If the IDF is
configured to shut down the unit down when this alert occurs
(
Configuration
→
UNIT
→
IDF.F
= YES
), then this alarm can
only be reset manually and the unit is shut down. If the IDF is
not configured to shut the unit down when this alert occurs
(
Configuration
→
UNIT
→
IDF.F
= NO
), then this alert resets
automatically and no specific control action is taken.
Alert Code T410 (R-W1 Jumper 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-
ture mode is the desired mode or add jumper between R and
W1. This alert resets automatically.
Alert Code T410 (R-W1 Jumper Must be Installed to Run
Heat in Service Test) — This alert occurs when a request for a
heat output has occurred yet the W1 input is not high. A jumper
must be installed between R and W1 when trying to test heat in
Service Test. The alert will clear when Service Test is exited or
if another Service Test mode is selected. Remove jumper when
done using Service Test if 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 turns On, the soft-
ware will behave as if Y1 and Y2 are both On. When Y2 turns
Off, the software will behave as if Y1 and Y2 are both Off.
This alert resets automatically when Y1 is turned On.
Summary of Contents for 48PG24
Page 68: ...68 Fig 14 Low Voltage Control Schematic 48PG20 28 Units without Humidi MiZer System a48 7627...
Page 69: ...69 Fig 15 Low Voltage Control Schematic 48PG20 28 Units with Humidi MiZer System a48 8227...
Page 70: ...70 Fig 16 Low Voltage Control Schematic 50PG20 28 Units without Humidi MiZer System a48 7778...
Page 71: ...71 Fig 17 Low Voltage Control Schematic 50PG20 28 Units with Humidi MiZer System a50 8101...
Page 72: ...72 Fig 18 Power Schematic Units without Humidi MiZer System a48 7628...
Page 73: ...73 Fig 19 Power Schematic Units with Humidi MiZer System a48 8228...
Page 74: ...74 Fig 20 Component Arrangement Units without Humidi MiZer System a48 8229...
Page 75: ...75 Fig 21 Component Arrangement Units with Humidi MiZer System a48 8230...
Page 105: ......