Carrier 30XA080-500 Controls, Start-Up, Operation, Service And Troubleshooting Instructions page 79

Repeated High Discharge Gas Overrides
Aimin 90 -- Circuit A (R37)
Almm 91 -- Circuit B (R38)
Akum 92 -- Circuit C (R39)
Cdwriafor Trip -- The criterion is tested when file circuit is
ON. This _flarm will be tripped if the circuit capacity is reduced
more than 8 times in 30 minutes due to high discharge gas tem-
peratures. If no override occurs in a 30-minute period, the
counter is reset.
A_Tion to be Taken -- The affected circuit will be shut down.
Reset Method -- Automatic, after 30 minutes. If file alann is
cleared via the Manual method, the counter will be reset to
zero.
Possible Causes -- If this condition is encountered, check the
following items:
• Maximum Condensing Temperature (MCT) for the
proper setting
• noncondensables in the refrigerant circuit
• condenser air re-circulation
• proper refrigerant charge (overcharged)
• operation beyond the limit of the machine
• condenser coils for debris or restriction
• condenser fans and motors for proper rotation and
operation
• discharge service valve to be sure that it is open. Check
the discharge pressure transducer for accuracy
• confirm unit configuration
Repeated Low Suction Temperature Protection
Aimin 93 -- Circuit A (R40)
Almm 94 -- Circuit B (R41)
Akum 95 -- Circuit C (R42)
CriWriafbr Trip -- The criterion is tested when file circuit is
ON. If the circuit operates and if more than 8 successive circuit
capacity decreases (stop the compressor) have occurred
because of low suction temperature protection ovemdes, the
circuit almm will be tripped. If no override has occurred for
more fllan 30 minutes, the override counter will be reset to zero
(LOSP).
Action to be Taken -- ALARM_LED will be set to blinking.
Alert rekiy will be energized.
Reset Method -- Automatic, when the override counter returns
to zero. If the almm is clemed via file Manual method, the
counter will be forced to zero.
Possible Causes -- If this condition is encountered, check the
following items:
• suction transducer for accuracy
• suction transducer wiring
• EXV operation
• proper refrigerant charge (undercharged)
• evaporator loop for low water flow
• evaporator leaving water temperature
• suction service valve to be sure it is open. Discharge
pressure transducer for accuracy
• confirm unit configuration
Alarm 96 -- Low Entering Water Temperature in Heating
NOTE: Alarm 96 is not used or supported. If this condition is
encountered, confirm machine configuration.
Condenser Default
Alm'm 97 -- Pump 1 (R73)
Aku'm 98 -- Pump 2 (R74)
NOTE: Alarms 97 and 98 are not used or supported. If this
condition is encountered, confirm machine configuration.
High Discharge Temperature
Alarm 99 -- Circuit A (R78)
Alarm 100 -- Circuit B (R79)
Alarm 101 -- Circuit C (R80)
Criteria for Trip -- Tile criterion is tested when file compressor
is operating. This almm will be tripped if the dischmge gas tem-
perature is higher than 212 F (100 C) for more than 90 seconds.
Action to be Taken -- The affected compressor will be
stopped.
Reset Method-- Manual.
Possible Causes -- If tiffs condition is encountered, check the
following items:
• Maximum Condensing Temperature (MCT) for the
proper setting
• noncondensables in the refrigerant circuit
• condenser air re-circulation
• proper refrigerant charge (overcharged)
• operation beyond the limit of the machine
• condenser coils for debris or restriction
• condenser fans and motors for proper rotation and operation
• the discharge service valve to be sure that it is open,
check the discharge pressure transducer for accuracy
• confirm unit configuration
Low Economizer Pressure
Alarm 102 -- Circuit A (R81 )
Alarm 103 -- Circuit B (E82)
Alarm 104 -- Circuit C (R83)
Criwria.for Tril) -- The criterion is tested when the compres-
sor is operating to prevent pumpdown conditions when the
suction service valve is closed. This alarm will be tripped if the
economizer pressure is below the suction pressure more than
1 bar (14.5 psi) for more than 10 seconds.
Action to be Taken -- The affected compressor will be
stopped.
Reset Method-- Manual.
Possible Causes -- If fills condition is encountered, check the
following items:
• suction service valve is closed
• sensor wiring to the EXV boards
• boards for faulty channels
• faulty transducer
• economizer EXV operation
Slide Valve Control Unverifiable
Alarm 105 -- Circuit A (R87)
Alarm 106 -- Circuit B (E88)
Alarm 107 -- Circuit C (R89)
Criwria.for TriF -- The criteria are tested when the compres-
sor is operating. This alarm will be tripped if:
• The circuit is operating at 100% of capacity and the mea-
sured current is less than 1.15 times the current at fully
unloaded 30% for more than one minute.
• The circuit is operating and is at a minimum load (30%
of capacity) and the measured current is greater than 0.78
expected current at 100% of capacity.
Action to be Taken -- The affected compressor will continue to
lain.
Reset Method-- Manual.
Possible Causes -- If tiffs condition is encountered, check the
following items:
• faulty unloader solenoid valves
• faulty unloader solenoid coils
• wiring of the unloader solenoid valves
• CPM board for faulty channels
• current transformer reading for accuracy
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