Carrier AQUASNAP 30RAP010-150 Controls, Start-Up, Operation, Service, And Troubleshooting page 80

T074 (Space Temperature Thermistor Failure) — This alert
occurs when the space temperature sensor is outside the range
of –40 to 245 F (–40 to 118 C). Failure of this thermistor will
disable any elements of the control which requires its use. The
cause of the alert is usually a faulty thermistor in the T55, or
T58 device, a shorted or open thermistor caused by a wiring er-
ror, or a loose connection.
T077 (Circuit A Saturated Suction Temperature exceeds
Cooler Leaving Fluid Temperature)
T078 (Circuit B Saturated Suction Temperature exceeds
Cooler Leaving Fluid Temperature) — Alert codes T077 and
T078 occur when a compressor in a circuit has been running
and the saturated suction temperature is greater than the cooler
leaving water temperature for 5 minutes. The alert is generated
and the circuit is shut down. The alert automatically resets
when the saturated suction temperature is less than the leaving
water temperature minus 1° F (0.5° C).
T090 (Circuit A Discharge Pressure Transducer Failure)
T091 (Circuit B Discharge Pressure Transducer Failure) —
Alert codes T090 and T091 are for circuits A and B, respec-
tively. These alerts occur when the pressure is outside the range
of 0.0 to 667.0 psig. A circuit cannot run when this alert is ac-
tive. Use the scrolling marquee to reset the alert. The cause of
the alert is usually a faulty transducer, faulty 5-v power supply,
or a loose connection.
T092 (Circuit A Suction Pressure Transducer Failure)
T093 (Circuit B Suction Pressure Transducer Failure)
Alert codes T092 and T093 are for circuits A and B, respec-
tively. These alerts occur when the pressure is outside the range
of 0.0 to 420.0 psig. A circuit cannot run when this alert is ac-
tive. Use the scrolling marquee to reset the alert. The cause of
the alert is usually a faulty transducer, faulty 5-v power supply,
or a loose connection.
T094 (Discharge Gas Thermistor Failure) — This alert oc-
curs for units which have the digital compressor installed on
circuit A. If discharge gas temperature is open or shorted, the
circuit will be shutoff. The alert will reset itself when discharge
temperature is less than 250 F (121.1 C). The cause of the alert
is usually low refrigerant charge or a faulty thermistor.
T110 (Circuit A Loss of Charge)
T111 (Circuit B Loss of Charge) — Alert codes T110 and
T111 are for circuits A and B, respectively. These alerts occur
when the compressor is OFF and the discharge pressure is less
than 26 psig.
T112 (Circuit A High Saturated Suction Temperature)
T113 (Circuit B High Saturated Suction Temperature)
Alert codes T112 and T113 occur when compressors in a cir-
cuit have been running for at least 5 minutes and the circuit sat-
urated suction temperature is greater than 70 F (21.1 C). The
high saturated suction alert is generated and the circuit is shut
down.
T114 (Circuit A Low Suction Superheat)
T115 (Circuit B Low Suction Superheat) — Alert codes
T114 and T115 occur when the superheat of a circuit is less
than 5 F (2.8 C) for 5 continuous minutes. The low superheat
alert is generated and the circuit is shut down.
T116 (Circuit A Low Cooler Suction Temperature)
T117 (Circuit B Low Cooler Suction Temperature) — Alert
codes T116 and T117 are for circuits A and B, respectively.
These alerts are generated if the capacity stages are reduced
three times without a 30 minute interval between capacity re-
ductions due to operating mode 7 or mode 8.
T118 (High Discharge Gas Temperature Alert)
A118 (High Discharge Gas Temperature Alarm) — This
alert or alarm occurs for units which have the digital compres-
sor installed on circuit A. If discharge gas temperature is great-
er than 268 F (131.1 C), the circuit will be shut off. The alert
will reset itself when discharge temperature is less than 250 F
(121.1 C). If this alert occurs 3 times within a day, the A118
alarm will be generated and the alarm must be reset manually.
The cause of the alert is usually low refrigerant charge or a
faulty thermistor.
T126 (Circuit A High Head Pressure)
T127 (Circuit B High Head Pressure) — Alert codes T126
and T127 are for circuits A and B, respectively. These alerts
occur when the appropriate saturated condensing temperature
is greater than the operating envelope shown in Fig 20A or
20B. Prior to the alert, the control will shut down one compres-
sor on a circuit if that circuit's saturated condensing tempera-
ture is greater than the maximum SCT minus 5° F (2.7° C). If
SCT continues to rise to greater than the maximum SCT, the
alert will occur and the circuit's remaining compressor will shut
down. The cause of the alarm is usually an overcharged sys-
tem, high outdoor ambient temperature coupled with dirty out-
door coil, non-condensables, faulty condenser fan motor,
plugged filter drier, or a faulty high-pressure switch.
T133 (Circuit A Low Suction Pressure)
T134 (Circuit B Low Suction Pressure) — Alert codes T133
and T134 are for circuits A and B, respectively. These alerts are
generated if one of the two following conditions is satisfied: the
circuit suction pressure is below 34 psig (234.4 kPa) for
8 seconds, or the suction pressure is below 23 psig (158.6 kPa).
The cause of this alert may be low refrigerant charge, plugged
liquid line filter drier, or sticking EXV. Check head pressure
—
operation. If not equipped, consider adding low ambient tem-
perature head pressure control.
Add wind baffles if required.
A140 (Reverse Rotation Detected) — A test is made once,
when compressor is energized, for suction pressure change on
the first activated circuit. The unit control determines failure as
follows:
1. The suction pressure of both circuits is sampled 5 seconds
before the compressor is brought on, right when the com-
pressor is brought on and 5 seconds afterwards.
2. The rate of suction pressure change from 5 seconds be-
fore the compressor is brought on to when the compres-
sor is brought on is calculated.
3. The rate of suction pressure change from when the
compressor is brought on to 5 seconds afterwards is
calculated.
4. With the above information, the test for reverse rotation is
made. If the suction pressure change 5 seconds after com-
pression is greater than the suction pressure change 5 sec-
—
onds before compression – 1.25, then there is a reverse
rotation error.
This alarm will disable mechanical cooling and will require
manual reset.
A150 (Unit is in Emergency Stop) — If the CCN emergency
stop command is received, the alarm is generated and the unit
will be immediately stopped.
If the CCN point name "EMSTOP" in the system table is
set to emergency stop, the unit will shut down immediately and
broadcast an alarm back to the CCN, indicating that the unit is
down. This alarm will clear when the variable is set back to
"enable."
A151 (Illegal Configuration) — An A151 alarm indicates an
invalid configuration has been entered. The following are ille-
gal configurations.
• Invalid unit size has been entered.
• Fluid is water with ICE making configurated.
• Incorrect AUX board installed with Motormaster config-
ured (AUX 1 must be used).
• Incorrect AUX software version (must be 3.0 or higher).
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