48
Table 36 — Alarm and Alert Codes (cont)
ALARM/ALERT
CODE
ALARM OR
ALERT
DESCRIPTION
WHY WAS THIS
ALARM GENERATED?
ACTION TAKEN
BY CONTROL
RESET METHOD
PROBABLE
CAUSE
31
Alert
Circuit B Economizer
Transducer Failure
Calibration offset more
than 6 PSIG (41 kPa) or
Voltage ratio (volts read/
ref. voltage) more than
99.9% or less than 0.5%
Circuit B shut down
Automatic
Transducer failure, power
supply failure, or wiring
damage/error.
32
Alarm
Transducer Supply Out-
side 4.5 to 5.5 Volts
Reference voltage mea-
sured at PSIO-1, J7-
34,35 less than 4.5 V or
greater than 5.5 V.
Chiller shut down
Automatic
Power supply failure or
wiring error. Low trans-
former voltage.
34
Alert
4-20 mA Reset Input Out
of Range
If configured and input
signal to PSIO-2,
J7-19,20(HX),
J7-22,23(GX) less than
2 mA or greater than
20mA
Reset function disabled.
Normal set point used
Automatic
Faulty signal generator,
wiring error, 500 ohm
resistor missing or not
properly installed.
35
Alert
4-20 mA Demand Limit
Input Out of Range
If configured and input
signal to PSIO-2,
J7-22,23(HX),
J7-13,14(GX) less than
2 mA or greater than
20mA
Demand limit ignored.
Runs under normal con-
trol based on 100%
demand limit.
Automatic
Faulty signal generator,
wiring error, 500 ohm
resistor missing or not
properly installed.
36
Alarm
Loss of Communication
with “Hardware Point”
PSIO-1 has lost commu-
nication with one of the
points in Table 37.
See Table 37.
Automatic
Failed module, wiring
error, failed transformer,
loose connection plug,
wrong address
37
Alert
Circuit A Low
Saturated Suction
Temperature
SST reads 6 F (3.3 C) or
more below the brine
freeze point for 3 min-
utes. For brines, SST
may also be 14 F (7.8 C)
or more below the lowest
cooling set point.
Circuit A shut down
Manual
Low refrigerant charge,
plugged strainer, faulty
expansion valve. Low
water flow.
38
Alert
Circuit B Low
Saturated Suction
Temperature
SST reads 6 F (3.3 C) or
more below the brine
freeze point for 3 min-
utes. For brines, SST
may also be 14 F (7.8 C)
or more below the lowest
cooling set point.
Circuit B shut down
Manual
Low refrigerant charge,
plugged strainer, faulty
expansion valve. Low
water flow.
40
Alert
Compressor A1 Low Oil
Pressure
See Note 1.
Comp A1 shut down
Manual
Low Water Temperature,
low refrigerant charge,
plugged oil filter, closed
oil valve, bad oil solenoid,
compressor oil check
valve stuck, oil line check
valve stuck, plugged oil
strainer
41
Alert
Compressor A2 Low Oil
Pressure
See Note 1.
Comp A2 shut down
Manual
Low Water Temperature,
low refrigerant charge,
plugged oil filter, closed
oil valve, bad oil solenoid,
compressor oil check
valve stuck, oil line check
valve stuck, plugged oil
strainer
42
Alert
Compressor B1 Low Oil
Pressure
See Note 1.
Comp B1 shut down
Manual
Low Water Temperature,
low refrigerant charge,
plugged oil filter, closed
oil valve, bad oil solenoid,
compressor oil check
valve stuck, oil line check
valve stuck, plugged oil
strainer
43
Alert
Compressor B2 Low Oil
Pressure
See Note 1.
Comp B2 shut down
Manual
Low Water Temperature,
low refrigerant charge,
plugged oil filter, closed oil
valve, bad oil solenoid,
compressor oil check
valve stuck, oil line check
valve stuck, plugged oil
strainer
44
Alarm
Circuit A Condenser
Freeze Protection (alarm
ignored for brine chillers)
For W/C chillers only, if
SCT < 34 F (1.1 C)
Chiller shut down. Turn
Cond. pump On if Chiller
is Off
Automatic
Failed/bad discharge
pressure transducer,
refrigerant leak,
configured for water-
cooled condenser
45
Alarm
Circuit B Condenser
Freeze Protection (alarm
ignored for brine chillers)
For W/C chillers only, if
SCT < 34 F (1.1 C)
Chiller shut down. Turn
Cond. pump On if Chiller
is Off
Automatic
Failed/bad discharge
pressure transducer,
refrigerant leak,
configured for water-
cooled condenser
46
Alarm
Cooler Freeze
Protection
Cooler EWT or LWT less
than freeze point. Freeze
point is 34 F (1.1 C) for
water, cooling set point
minus 8 F (4.4 C) for
brines.
Chiller shut down.
Leave Cooler pump on.
Turn Cooler pump On if
Chiller is Off.
Automatic**
Faulty thermistor, low
water flow
