Trane R Series Installation Operation & Maintenance page 149

Table 28 Diagnostic Codes
Diagnostic Description
Low Oil Flow - Cprsr A
Low Oil Flow - Cprsr B
Low Oil Flow - Cprsr C
Low Oil Flow - Cprsr D
Low Pressure Cutout - Ckt 1
Low Pressure Cutout - Ckt 2
Low Superheat - Ckt 1
Low Superheat - Ckt 2
Memory Error Type I
Memory Error Type II
Memory Error Type III
RLC-SVX07A-EN
Diagnostics
Type Cause
CMR The differential oil pressure switch remained opened for more
than 20 contiguous seconds on Cprsr A.
Note: Although GP cmprs do not have pressure switch or Oil
Line solenoid, this diagnostic is still active. The input must be
jumpered for normal operation on GP cmprs.
CMR Same as Diagnostic for Cprsr A, above, but Cprsr B.
CMR Same as Diagnostic for Cprsr A, above, but Cprsr C.
CMR Same as Diagnostic for Cprsr A, above, but Cprsr D.
CMR The low pressure switch opened or remained open past the
ignore time during compressor operation (after one retry) or
the low pressure switch was open prior to compressor start
with Sat Cond Temp above -18F .
CMR Same as Ckt 1.
CMR A low superheat condition existed for an extended period of
time. If a superheat less than or equal to 2 degrees F (1.11
degrees C) is detected for more than 2400 degree F seconds,
the circuit shall be shutdown. The integrated area (2400
Degree F seconds) shall be only below 2 degrees F superheat.
CMR Same as Diagnostic for Ckt 1, above.
IFW On UCM either power up or following a Type II Memory Error a
NOVRAM memory error was detected. The UCM is operating
on all Engineering ROM defaults for all setup parameters.
Check all setup parameters and continue to run chiller. Replace
the Chiller Module as soon as a replacement is available.
NOTE: It is expected that this diagnostic will be
detected on the very first power up of the Chiller
Module at the Manufacturer since the NOVRAM will
not contain valid data on first power up.
IFW A Shadow RAM memory error was detected. The UCM is
operating on all last valid values (pulled from NOVRAM) for all
setup parameters. No setup parameter changes were pending
to be loaded into NOVRAM, a complete recovery of all setup
parameters was made and there is no need to check unit setup
parameters. Compressor starts and hour were lost for not
more than the last 24 hours. This is expected to be an isolated
event and repair or replacement is not required. If this
diagnostic does occur repeatedly, then replace the Chiller
module.
IFW A Shadow RAM memory error was detected. The UCM is
operating on all last valid values (pulled from NOVRAM) for all
setup parameters. Setup parameter changes less than 24
hours old pending to be loaded into NOVRAM were lost. Check
all setup parameters made in the last 24 hours. Compressor
starts and hours were lost for not more than the last 24 hours.
This is expected to be an isolated event and repair or
replacement is not required. If this diagnostic does occur
repeatedly, then replace the Chiller module.
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