Installation and Maintenance Manual

Diagnostics
RLC-SVX09H-EN 203
Low Differential
Refrigerant Pressure -
Circuit 2
Circuit Immediate Latch Cprsr Energized
The system differential pressure for the
respective circuit was below 25 Psid (240.5
kPa) while its compressor was unstepped or
pressure ratio was below 1.75 if stepped - for a
varying period of time – refer to specification
for trip time as a function of system DP below
the requirement
Remote
Low Discharge
Superheat – Circuit 1
Circuit 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 circuit
startup the Discharge Superheat will be ignored
for 5 minutes.
Remote
Low Discharge
Superheat – Circuit 2
Circuit 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 circuit
startup the Discharge Superheat will be ignored
for 5 minutes.
Remote
Low Evaporator
Refrigerant Pressure -
Circuit 1
Circuit Immediate Latch
Cprsr Prestart and
Cprsr Energized
a. The Evap Refrig Pressure dropped below 10
Psia just prior to compressor start (after EXV
preposition). b. For RTUD A (C during early
startup period: The Evap Refrig Pressure fell
below the Condenser Pressure ÷ 8, limited to
between 2 and 10 psia. c. For RTWD (or RTUD,
ACFC=none) during early startup period: The
Evap Refrig Pressure fell below 10 Psia. d. For
all chiller types, after early Startup Period
expires: The Evap Refrig Pressure fell below 16
Psia.
(Note: the Startup Period for RTWD is 3 min ;
for RTUD it is between 1 and 5 min for as an
inverse function of the Cond Temp measured at
time of circuit startup).
Local
Low Evaporator
Refrigerant Pressure -
Circuit 2
Circuit Immediate Latch
Cprsr Prestart and
Cprsr Energized
a. The Evap Refrig Pressure dropped below 10
Psia just prior to compressor start (after EXV
preposition). b. For RTUD A (C during early
startup period: The Evap Refrig Pressure fell
below the Condenser Pressure ÷ 8, limited to
between 2 and 10 psia. c. For RTWD (or RTUD,
ACFC=none) during early startup period: The
Evap Refrig Pressure fell below 10 Psia. d. For
all chiller types, after early Startup Period
expires: The Evap Refrig Pressure fell below 16
Psia.
(Note: the Startup Period for RTWD is 3 min; for
RTUD it is between 1 and 5 min for as an inverse
function of the Cond Temp measured at time of
circuit startup).
Local
Low Evaporator
Refrigerant
Temperature - Circuit 1
Circuit Immediate Latch
All Ckt Running
Modes
The inferred Saturated Evap Refrigerant
Temperature (calculated from suction pressure
transducer dropped below the Low Refrigerant
Temperature Cutout Setpoint for 1125?F-sec
(25?F-sec max rate) while the circuit was
running. The minimum LRTC setpoint is -5?F
(18.7 Psia) the point at which oil separates from
the refrigerant. During the time that the trip
integral is non zero, the unload solenoid(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 decays to zero by
temps above the cutout setpoint. The integral
is held nonvolatily though power down, is
continuously calculated, and can decay during
the circuit’s off cycle as conditions warrant.
Remote
Table 134. Main Processor Diagnostics (continued)
Diagnostic Name
Affects
Target Severity Persistence
Active Modes
[Inactive
Modes] Criteria
Reset
Level