Trane RTHC Installation Operation & Maintenance page 140

Diagnostic Diagnostic
Description Type
External Current IFW-AR
Limit Setpoint
EXV Electrical MMR
Drive Circuit
High Cprsr MMR
Discharge Temp.
High Diff. Rfgt MMR
Pressure
High Evaporator MMR
Liquid Level
High Pressure MMR
Cutout Tripped
High Restart IFW
Inhibit Timer
Warning
Incorrect Chiller MMR
Software Installed
Incorrect Stepper MMR
Software Installed
Loss of Oil at MMR
Compressor
(Running)
Loss of Oil at MMR
Compressor
(Stopped)
Low Chilled IFW-AR
Water Temp: Unit
Off
Low Chilled MAR
Water Temp: Unit
On
10 - 6
Shutdown
Action
N/A a. Not "Enabled": no diagnostics.
b. "Enabled ": Out-Of-Range Low or Hi, set diagnostic, default CLS
to next level of priority (e.g. Front Panel SetPoint. This IFW
diagnostic will automatically reset if the input returns to the normal
range.
N/A The Stepper module has detected a wiring or motor fault on the EXV
output circuit just prior to EXV pre-position. The EXV motor is not
driven if a problem is detected. Miswires or faults that occur in the off
cycle can be detected and damage to module prevented at start-up.
Immediate a. The discharge temp. exceeded 190
b. Time to trip from trip value exceeded shall be 0.5 to 2.0 seconds.
(Note: The trip may be an "instantaneous trip" but consistent with the
analog input filtering function.)
c. Immediate shutdown is preferred over friendly because unloading
the compressor will generally increase the discharge temperature.
Friendly a. The difference between the Condenser pressure and the
evaporator pressure exceeded 160 PSID for 0.8-5.0 seconds. 152
PSID must hold, 152+ to trip in one hour.
Friendly The liquid level sensor is seen to be at or near its high end of range
for 80 continuous minutes while the compressor is running
Immediate A high pressure cutout was detected. C.O. on rise @ 180 psig, reset
at 135 psig (+/-5 psid on switching tolerance) Note: Pressure relief
valve is 200 Psi +/- 2%,
N/A The restart inhibit timer has reached a maximum threshold of 15
minutes. This indicates excessive chiller cycling, steps should be
taken to correct this.
N/A The incorrect EPROM was loaded into this module. This diagnostic
is detected when a factory test computer sets the unit type to
something other than what the EPROM software was intended.
N/A The incorrect EPROM was loaded into this module. This diagnostic
is detected when a factory test computer sets the unit type to
something other than what the EPROM software was intended.
Immediate In Running modes, Oil sensor detects lack of oil in line i.e. sensor
terminal voltage above 11.5 volts (clamped at 14.0 volts) for 23 volt-
seconds (778 bit for 1600 bit count-seconds). Upon transition from
wet to totally dry, a trip will occur in 15 seconds nominally
(distinguishing a liquid flow from a vapor flow).
Oil Sensor detects a lack of oil trapped in line feeding compressor
for 2 continuous minutes after the oil line solenoid is opened for pre-
start mode. Note: Compressor start is delayed (up to an additional
90 sec) from the normal 30 sec of pre-start, waiting for oil to be
detected
N/A a. The chilled water temp. fell below the cutout setpoint while the
compressor was not running for 30
the IFW diag shall occur 2
Friendly a. The chilled water temp. fell below the cutout setpoint while the
compressor was running for 30
MAR diag shall occur 2
Cause
° °
F + or - 5 F.
°
F Seconds. Automatic Reset of
° °
F (1.1 C) above the cutout setpoint.
°
F Seconds. Automatic Reset of the
° °
F (1.1 C) above the cutout setpoint.
Help Message
Check Signal At
Input
Check Stepper
Module, Wiring, &
Motor.
See
Troubleshooting
Service Bulletin
See
Troubleshooting
Service Bulletin
Check EXV,
Sensor, Stpr
Module & Rfgt
Charge
Check Condenser
Water Temp.
Check for
Excessive Chiller
Cycling
No Message
Required
No Message
Required
Check Oil System
(Master Oil Line
Solenoid Valve &
Oil Return System
& Oil Detector
Sensor)
Check Oil System
(Master Oil Line
Solenoid Valve &
Oil Return System
& Oil Detector
Sensor)
Check Flow,
Sensor, Wiring and
Rapid Load Loss
Check Flow,
Sensor, Wiring and
Rapid Load Loss
RTHC-IOM-1C