Installation and Maintenance Manual

Diagnostics
RTAE-SVX001B-EN 79
High
Evaporator
Refrigerant
Pressure
Chiller Immediate NonLatch All
The evaporator refrigerant pressure of either circuit has risen
above 190 psig. The evaporator water pump relay will be de-
energized to stop the pump regardless of why the pump is
running. The diagnostic will auto reset and the pump will return
to normal control when all of the evaporator pressures fall
below 185 psig. The primary purpose is to stop the evaporator
water pump and its associated pump heat from causing
refrigerant side pressures, close to the evaporator relief valve
setting, when the chiller is not running, such as could occur with
Evap Water Flow Overdue or Evaporator Water Flow Loss
Diagnostics.
Remote
High
Evaporator
Water
Temperature
Chiller
Info and
Special
Action
NonLatch
Only effective if
either 1)Evap
Wtr Flow
Overdue, 2)Evap
Wtr Flow Loss, or
3)Low Evap Rfgt
Temp,-Unit Off,
diagnostic is
active.
Either the leaving or the entering water temperature exceeded
the high evap water temp limit (TV service menu settable –
default 105°F) for 15 continuous seconds. The evaporator
water pump relay will be de-energized to stop the pump but
only if it is running due one of the diagnostics listed on the left
. The diagnostic will auto reset and the pump will return to
normal control when both the entering and leaving
temperatures fall 5°F below the trip setting. The primary
purpose is to stop the evaporator water pump and its
associated pump heat from causing excessive waterside
temperatures and waterside pressures when the chiller is not
running but the evap pump is on due to either Evap Water Flow
Overdue, Evaporator Water Flow Loss, or Low Evap Temp – Unit
Off Diagnostics. This diagnostic will not auto clear solely due to
the clearing of the enabling diagnostic.
Remote
High Motor
Winding
Temperature -
Cprsr1A
Circuit Immediate Latch All
Any of the compressor’s motor winding temperature sensors is
seen to be beyond the windings rated temperature of 265°F
(129.4°C)
Local
High Motor
Winding
Temperature -
Cprsr2A
Circuit Immediate Latch All
Any of the respective compressor’s motor winding temperature
sensors is seen to be beyond the windings rated temperature
of 265°F (129.4°C)
Local
High Pressure
Cutout -
Cprsr1A
Circuit Immediate Latch All
A high pressure cutout was detected by AFD 1A Gate Kill Input
; trip at 315 ± 5 PSIG.
Local
High Pressure
Cutout -
Cprsr2A
Circuit Immediate Latch All
A high pressure cutout was detected by AFD 2A Gate Kill Input
; trip at 315 ± 5 PSIG.
Local
High
Refrigerant
Pressure Ratio
– Ckt1
Circuit Immediate Latch Cprsr Energized
The pressure ratio for the respective circuit exceeded 12.3 for
1 contiguous minute while running in any mode. The pressure
ratio is defined as Pcond (abs)/Pevap(abs).
Remote
High
Refrigerant
Pressure Ratio
– Ckt2
Circuit Immediate Latch Cprsr Energized
The pressure ratio for the respective circuit exceeded 12.3 for
1 contiguous minute while running in any mode. The pressure
ratio is defined as Pcond (abs)/Pevap(abs).
Remote
Interrupt
Failure – AFD1A
Circuit
Immediate
Shutdown
and Special
Action
Latch
AFD intended to
be OFF
Respective AFD is reporting that it is still running the
compressor when the MP has commanded the drive/
compressor to be Off. Detection time shall be 10 seconds
minimum and 15 seconds maximum. On detection and until the
controller is manually reset: this diagnostic shall be active and
the alarm relay shall be energized, the Evap Pump Output will
be energized, the effected compressor will be continually
commanded off, and be unloaded, while a normal stop shall be
commanded to all other compressors. For as long as
compressor operation continues, the MP shall continue liquid
level, oil return, and fan control on the circuit effected.
Local
Table 33. Main processor diagnostics (continued)
Diagnostic
Name
Affects
Target Severity Persistence
Active Modes
[Inactive
Modes] Criteria
Reset
Level