Diagnostics
RTHD-SVX01K-EN 79
High Motor
Winding Temp
Chiller Immediate Latch All
Any of the compressor’s motor winding temperature
sensors is seen to be beyond the windings rated
temperature of 260°F (126.7°C)
Local
High Pressure
Cutout
Chiller Immediate Latch All
A high pressure cutout was detected; C.O. on rise @ 180
psig, reset @ 135 psig (+/-5 psi on switching tolerance)
Note: Pressure relief valve is 200 Psig +- 2% trip at 315
± 5 psi. Note: Other diagnostics that may occur as an
expected consequence of the HPC trip will be suppressed
from annunciation. These include Phase Loss, Power Loss,
and Transition Complete Input Open.
Local
High Refrigerant
Pressure Ratio
Chiller Immediate Latch
Service Pumpdown
Only
The system pressure ratio exceeded 5.61 for 1 contiguous
minute. This pressure ratio is a fundamental limitation of
the compressor. The pressure ratio is defined as Pcond
(abs)/Pevap(abs).
Remote
Loss of Oil at
Compressor
(Running)
Chiller Immediate Latch
Starter Contactor
Energized
In running modes, Oil Loss Level Sensor detects lack of oil
in the oil tank feeding the compressor (distinguishing a
liquid flow from a vapor flow)
Local
Loss of Oil at
Compressor
(Stopped)
Chiller
Immediate
and Special
Action
Latch
Compressor Pre-
start [all other
modes]
Oil Loss Level Sensor detects a lack of oil in the oil tank
feeding the compressor for 90 seconds after EXV
preposition is completed. Note: Compressor start is
delayed while waiting for oil to be detected.
Local
Low Differential
Refrigerant
Pressure
Chiller Immediate Latch Chiller Energized
The system differential pressure was either below 15 Psid
for more than 164 Psid-sec, or below 23.0 Psid for 3000
Psid-sec. The latter integral’s value is not cleared for any
reason including diagnostic trip, manual reset, or power up
reset (ie. Integral is saved non-volatile on power down).
The integral will decay while circuit is running at a max rate
of –10 PSID, and while stopped at a rate of –0.4 PSID. This
same integral is associated with the operating mode
“Compressor Cool Down”. Also see diagnostic below
Remote
Low Discharge
Superheat
Chiller Normal Latch Any Running Mode
While Running Normally, the Discharge Superheat was less
than 12 degrees F +- 1F for more than 6500 degree F
seconds.. At startup the UCM shall ignore the Discharge
Superheat for 5 minutes.
Remote
Low Evaporator
Liquid Level
Chiller Warning NonLatch
Starter Contactor
Energized [all Stop
modes]
The liquid level sensor is seen to be at or near its low end
of range for 80 contiguous minutes while the compressor
is running. Design: 20% or less of bit count corresponding
to –21.2 mm or less liquid level for 80 minutes)
Remote
Low Evaporator
Refrigerant
Pressure
Chiller Immediate Latch
Chiller Prestart and
Chiller Energized
The Evaporator Refrigerant Pressure dropped below 10
psia just prior to compressor start. The pressure fell below
10 psia while running but before the 3 minute ignore time
had expired or fell below 16 Psia after the 3 minute ignore
time had expired.
Local
Low Evaporator
Refrigerant
Temperature
Chiller Immediate Latch
All Ckt Running
Modes
b. During the timeout of the trip integral, the unload
s
olenoid(s) of the running compressors on the circuit, shall
be energized continuously and the load solenoid shall be
off. Normal load/unload operation will be resumed if the
trip integral is reset by return to temps above the cutout
setpoint."
Remote
Low Evaporator
Temp: Unit Off
Chiller
Warning
and Special
Action
NonLatch
Unit in Stop Mode,
or in Auto Mode and
No Ckt's Energizd
[Any Ckt Energizd]
The evap sat temp fell below the water temp cutout setting
while the respective evap liquid level was greater than –
21.2mm for 30 (or 150 beginning with rev 08) degree F
seconds while Chiller is in the Stop mode, or in Auto mode
with no compressors running. Energize Evap Water pump
Relay until diagnostic auto resets, then return to normal
evap pump control. Automatic reset occurs when either
the evap temp rises 2°F (1.1°C) above the cutout setting
or the liquid level falls below –21.2mm for 30 minutes
Remote
Low Evaporator
Water Flow
Chiller Warning NonLatching
Chiller Auto, manual
water pump and All
Running Modes
a. The evap. water flow measurement option was installed
and the flow dropped to or below the Evaporator Low Water
Flow Warning Setpoint in TV. This IFW shall be Auto Reset
and reset 0.1 gpm/ton above the adjustable trip point or
when the Evaporator water pump is turned off.
b. See Water Flow and Tons Sensing specification for
additional information.
Remote
Table 26. Main processor diagnostics (continued)
Diagnostic
Name and
Source
Affects
Target Severity Persistence
Active Modes
[Inactive
Modes] Criteria
Reset
Level
To Next Page
Loading...
