AC-SVX002C-EN
75
Table 31.
Main process diagnostics (continued)
Diagnostic
Name
Affects
Target
Severity
Persistence
Active
Modes
[Inactive
Modes]
Criteria
Reset
Level
Inverted Water
Temp
(Heating)
Chiller
Warning/
Normal
NonLatch/
Latch
Unit energized
and all ckts’
reversing
valves in
heating
direction [Unit
de-energized
or any ckt’s
reversing valve
in cooling
direction]
Not Enabled (Default): diagnostic is Non-Latching
and Warning. Enabled: diagnostic is Latching and
Normal Shutdown. The leaving evaporator water
temp fell below the entering evaporator water
temperature by more than 3°F for 100°F-sec. There
is a 60 second ignore time after the condition to
enable the diagnostic is met. During the ignore time,
the temperature error is not integrated. Diagnostic
will auto clear if the entering water temp – leaving
water temp < 3F. It can warn of improper flow
direction through the evaporator, misbound water
temperature sensors, improper sensor installation,
partially failed sensors, or other system problems.
Note that either entering or leaving water temp
sensor or the water system could be at fault.
Remote
Low
Evaporator
Water Temp:
Unit On
Chiller
Immediate
Shutdown and
Special Action
NonLatch
Any Ckt[s]
Energzd [No
Ckt(s)
Energzd]
The evaporator entering or leaving water temp fell
below the cutout setpoint for 30° F-seconds while the
compressor was running. Automatic reset occurs
when both of the temperature rises 2 °F (1.1°C)
above the cutout setting for 2 minutes. This
diagnostic shall not de-energize the Evaporator
Water Pump Output
Remote
Low
Evaporator
Water Temp
(Unit Off)
Evap Pump and
Freeze
Avoidance
Request Relay
Info and
Special Action
NonLatch
Unit in Stop
Mode, or in
Auto Mode and
No Ckt(s)
Energzd [Any
Ckt Energzd]
Either the entering or leaving evaporator water temp
fell below the evaporator water temp cutout setting
for 30 °F-seconds while the Chiller is in the Stop
mode, or in Auto mode with no compressors running.
Energize Freeze Avoidance Request Relay and Evap
Water Pump Relay until diagnostic auto resets, then
de-energize the Freeze Avoidance Request Relay and
return to normal evap pump control. Automatic reset
occurs when both temps rise 2°F (1.1°C) above the
cutout setting for 30 minutes, or either circuit starts.
This diagnostic even while active, does not prevent
operation of either circuit
Remote
Low
Refrigerant
Temperature
Circuit
Immediate
Latch
Circuit
Energized
[Service
Pumpdown,
Operational
Pumpdown]
The suction saturated refrigerant temperature
dropped below the Low Refrigerant Temperature
Cutout Setpoint for 16.67°C-seconds (30°F-
seconds). See Low Refrigerant Temperature
Protection spec for more details.
Local