Trane RTHC - Page 102

Diagnostic Table
96 RTHC-SVD01B-EN
Loss of Oil at
Compressor
(Running)
MMR
immediate
Chiller
1U1
starter
contactor
energized
In Running modes , Oil sensor detects lack
of oil in line for 1600 bit count-seconds
seconds. (distinquishing a liquid flow from
a vapor flow)
Check Oil System
(Master Oil Line
Solenoid Valve & Oil
Return System & Oil
Detector sensor)
Loss of Oil at
Compressor
(Stopped)
MMR
n/a
Chiller
1U1
compressor
pre-start
Oil Sensor detects a lack of oil trapped in
line feeding compressor for 2 contiguous
minutes after the oil line solenoid is opened
for pre-start mode. Note: Compressor start
is delayed (up to an additional 90s) from
the normal 30 second s of pre-start, waiting
for oil to be detected
Check Oil System
(Master Oil Line
Solenoid Valve, Oil
Return System & Oil
Detector sensor
Low Chilled
Water Temp:
Unit Off (Unit in
Auto but not
Starting or
Running)
IFW
n/a
Chiller
1U1
Unit in Auto The chilled water temp. fell below the
cutout setpoint while the compressor was
not running for 30 degree F Seconds.
Automatic Reset of the IFW diag shall
occur 2 degrees F (1.1 C) above the cutout
setpoint.
Check flow, sensor, &
wiring.
Low Chilled
Water Temp:
Unit On (Unit
Starting or
Running)
MAR
friendly
Chiller
1U1
Unit starting
or running
The chilled water temp. fell below the
cutout setpoint while the compressor (or
Solution Pump) was running for 30 degree
F Seconds. Automatic Reset of the MAR
diag shall occur 2 degrees F (1.1 C) above
the cutout setpoint.
Check flow, sensor, &
wiring.
Low Diff Rfgt
Pressue
Switch
MAR
Chiller
1U1
Initiated at
Prestart active
in all modes
The Low Differential Rfgt Pressure Switch,
sensing system differential pressure, (See
diagnostic 297 above), has inhibited a start
and was seen to be still closed 2 minutes
after the intention to start.
Check Low Differential
Pressure Switch & its
valving, EXV
Low Diff Rfgt
Pressure,m
Cold Cond
Water
MMR
friendly
Stepper
1U3
Cprsr
Energized
Inferred system differential pressure is less
thatn 23.8 PSID for 3000PSID-sec.
Check cond water.
Table 14-2: Diagnostic Table
Diagnostic
Description
Type/
Shutdown
Action
Module
Calling
Out Diag.
Operating
Modes
Diagnostic is
Active
Cause Help Message