78
AC-SVX002C-EN
Table 31.
Main process diagnostics (continued)
Diagnostic
Name
Affects
Target
Severity
Persistence
Active
Modes
[Inactive
Modes]
Criteria
Reset
Level
Evaporator
Pump 2 Fault
Chiller
Immediate or
Warning and
Special Action
NonLatch
All
For systems with no evaporator pump, a single
evaporator pump, or a single inverter driving dual
evaporator pumps, an immediate shutdown shall be
performed. For multiple pump systems, detection of
a pump fault will generally cause pump control to
switch to the redundant pump. For single inverter,
dual pump configuration, switching to the redundant
pump can only happen after the fault is cleared.
Specific details of special action are described in
Evaporator_Water_Pump_Control.
Remote
Low Suction
Superheat
Circuit
Immediate
Latch
Ckt Energized
[Ckt Not
Energized]
Measured suction superheat stays below 2.22 °C for
one continuous minute in cooling mode or 3 minutes
in heating mode, with a 1 minute ignore time from
the start of the circuit.
Suction Superheat = suction temp – sat. suction
temp.
Local
High
Compressor
Pressure
Differential
Circuit
Immediate
Latch
Ckt Energized
[Ckt Not
Energized or
Operational
Pumpdown]
Compressor involute pressure differential exceeded
allowable limits. See Compressor Involute Pressure
Differential Protection spec for details.
Local
Low
Refrigerant
Pressure Ratio
Circuit
Normal
Latch
Ckt Energized
[Ckt Not
Energized]
The refrigerant pressure ratio between compressors
outlet and inlet of a given circuit exceeded allowable
limits. See Low Refrigerant Pressure Ratio Protection
spec for details
Local
Low Discharge
Saturated
Temperature
Circuit
Normal
Latch
Ckt Energized
[Ckt Not
Energized]
The discharge saturated temperature for the
respective circuit was below 10 °C for more than
2250 °C-sec, with a 10 minutes ignore time from the
start of the circuit. Integration starts after the ignore
time is completed.
Local
Loss of Charge
Circuit
Immediate
Latch
Ckt Energized
[Ckt Not
Energized]
For Release 1.0, this feature is factory enabled for
glycol applications only. The diagnostic occurs if the
EXV (normal cooling mode only) is consistently and
significantly more open than internal models predict
for the conditions. This would occur with lack of
subcooling from the condenser, a condition that
generally suggests undercharging or charge loss.
Pressure sensor errors or excessive compressor
capacity over the commanded capacity could also
cause this diagnostic. (Adjustment is available to
mitigate nuisance tripping)
Local
Chiller Service
Recommended
Chiller
Warning
Latch
Service
Messages
Enabled
Chiller service interval time has elapsed. Chiller
service is recommended.
Remote
Evap Water
Pump 1 Svc
Recommended
Chiller
Warning
Latch
Service
Messages
Pump service recommended as service interval hours
have elapsed.
Remote
Evap Water
Pump 2 Svc
Recommended
Chiller
Warning
Latch
Service
Messages
Enabled
Pump service recommended as service interval hours
have elapsed.
Remote
Mfr
Maintenance
Recommended
- xy
Cprsr
Warning
Latch
Service
Messages
Enabled
Compressor service recommended as service
interval hours have elapsed.
Remote
Restart Inhibit
Invoked - xy
Cprsr
Warning
NonLatch
All
When restart inhibit warning is enabled, the warning
exists when unit has been inhibited from starting and
is cleared when a start of a compressor is possible
(Start-to-Start Timer expires)
Remote