Installation and Maintenance Manual

Diagnostics
RTAE-SVX001B-EN 77
Drive Cooling
Supply Temp
Sensor – Ckt2
Circuit Normal Latch All Bad Sensor or LLID. Remote
Emergency
Stop
Chiller Immediate Latch All
EMERGENCY STOP input is open. An external interlock has
tripped. Time to trip from input opening to unit stop shall be 0.1
to 1.0 seconds.
Local
Evap Rfgt Pool
Temp Sensor –
Ckt1
Circuit and
Chiller
Special
Action and
Info
NonLatch All
Bad Sensor or LLID. Note: The Evap Pool Temp Sensors are
used for evaporator freeze protection (running and non-
running).
Remote
Evap Rfgt Pool
Temp Sensor –
Ckt2
Circuit and
Chiller
Special
Action and
Info
NonLatch All
Bad Sensor or LLID. Note: The Evap Pool Temp Sensors are
used for evaporator freeze protection (running and non-
running).
Remote
Evap Rfgt Pool
Temp Sensor
Error – Ckt1
Circuit
Info and
Special
Action
Latch
Ckt Energized
[Ckt Not
Energized
The evaporator refrigerant pool temperature sensor is
indicating a temperature significantly warmer than the
evaporator entering water temperature (by more than 7.2°F
for 5 continuous min excluding ckt nonoperation and a 2 min
ignore time relative to ckt startup). While this diagnostic is
active, it will invalidate the evaporator pool temperature
sensor. Freeze protection functions (i.e. freeze diagnostics and
Evap Pump Override) will default to the respective evaporator
pressure transducer and its calculated saturation temperature.
Local
Evap Rfgt Pool
Temp Sensor
Error – Ckt2
Circuit
Info and
Special
Action
Latch
Ckt Energized
[Ckt Not
Energized
The evaporator refrigerant pool temperature sensor is
indicating a temperature significantly warmer than the
evaporator entering water temperature (by more than 7.2°F
for 5 continuous min excluding ckt nonoperation and a 2 min
ignore time relative to ckt startup). While this diagnostic is
active, it will invalidate the evaporator pool temperature
sensor. Freeze protection functions (i.e. freeze diagnostics and
Evap Pump Override) will default to the respective evaporator
pressure transducer and its calculated saturation temperature.
Local
Evap Spillover
Liquid Level
Sensor – Ckt1
Circuit Normal Latch All Bad Sensor or LLID Remote
Evap Spillover
Liquid Level
Sensor – Ckt2
Circuit Normal Latch All Bad Sensor or LLID Remote
Evap Water
Flow (Entering
Water Temp)
None Info NonLatch
Any Ckt
Energized [No
Ckts Energized]
The entering evaporator water temp fell below the leaving
evaporator water temp by more than 2°F for 180°F-sec,
minimum trip time 30 seconds. 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
Evaporator
Approach Error
– Ckt1
Circuit Immediate Latch
Respective
circuit running
The Evaporator approach temperature for the respective circuit
(ELWT – Evap Sat Temp Ckt 1) is negative by more than 10°F
for 1 minute continuously while the circuit / compressor is
operating. Either the Evap Leaving Water Temp sensor, or Evap
Suction Rfgt Pressure Transducer Ckt 1 is in error.
Remote
Evaporator
Approach Error
– Ckt2
Circuit Immediate Latch
Respective
circuit running
The Evaporator approach temperature for the respective circuit
(ELWT – Evap Sat Temp Ckt 2) is negative by more than 10°F
for 1 minute continuously while the circuit / compressor is
operating. Either the Evap Leaving Water Temp sensor, or Evap
Suction Rfgt Pressure Transducer Ckt 2 is in error.
Remote
Evaporator
Entering Water
Temp Sensor
Chiller Normal Latch All
Bad Sensor or LLID. Note: Entering Water Temp Sensor is used
in EXV pressure control as well as ice making so it must cause
a unit shutdown even if ice or CHW reset is not installed.
Remote
Evaporator
Leaving Water
Temp Sensor
Chiller Normal Latch All Bad Sensor or LLID Remote
Evaporator
Water Flow Lost
Chiller Immediate NonLatch [All Stop modes]
a. The Evaporator water flow switch input was open for more
than 6 contiguous seconds (or 15 seconds for thermal
dispersion type flow switch). b. This diagnostic does not de-
energize the evap pump output. c. 6 seconds of contiguous flow
shall clear this diagnostic.
Remote
Table 33. Main processor diagnostics (continued)
Diagnostic
Name
Affects
Target Severity Persistence
Active Modes
[Inactive
Modes] Criteria
Reset
Level