111
RTAA-IOM-3
Table 18
Diagnostics and Troubleshooting Chart (Continued)
DIAG. ACTIVE
CODE DIAGNOSTIC DESCRIPTION TYPE MODES CAUSE
NONE Outdoor Air Temperature None All Open or Short
Sensor (Both Outdoor Air a. Display dashes e.g. 14 - - - - -”,
Reset or Low Ambient Lockout
Not Selected)
Ab Evap. Leaving Water Temp. Sensor MMR All Open or Short
bA Overload Trip - Compressor A CMR Compressor Energized Compressor current exceeded overload
time vs. trip characteristic.
bb Overload Trip - Compressor B CMR Compressor Energized Compressor current exceeded overload
time vs. trip characteristic.
bC Overload Trip - Compressor C CMR Compressor Energized Compressor current exceeded overload
time vs. trip characteristic.
bd Overload Trip - Compressor D CMR Compressor Energized Compressor current exceeded overload
time vs. trip characteristic.
bE High Pressure Cutout - Compressor C CMR All a. A high pressure cutout was detected on
Compressor C; trip at 405 + or - 7 PSIG.
BF High Pressure Cutout - Compressor D CMR All a. A high pressure cutout was detected on
Compressor D; trip at 405 + or - 7 PSIG.
NONE CWS/Leaving Water Temp. None All No diagnostic, display to flash and
Cutout Setpoint Overlap limit value to last legal value.
NOTE: The above is not a diagnostic because you don’t want the display vectoring you to a different display state when you
are trying to set either the chilled water setpoint or the leaving water temp. cutout setpoint as it will in the case of a diagnostic.
C5 Low Chilled Water Temperature IFW No Circuits Energized a. The chilled water temp. fell below
(Unit Off) the cutout setpoint while the
compressors were not running.
C6 Low Chilled Water Temperature MAR Any Circuit Energized a. The chilled water temp. fell below
(Unit On) the cutout setpoint while the
compressors were running for 30 F - sec.
CA Contactor - Compressor A MMR Compressor a. Welded compressor contactor.
Not Energized b. Detected a welded compressor contactor
off but the current does not go to zero.
Detection time shall be 5 second
minimum and 10 seconds maximum.
On detection, generate the diagnostic,
energize the appropriate alarm relay,
continue to command the affected
compressor off, energize the affected
compressors oil line solenoid, stop all
other compressors, unload the running
compressor with the welded contactor,
open the EXV to it’s maximum open
position, and continue to do fan control.
Do not exit this condition until the
controller is manually reset.
Cb Contactor - Compressor B MMR Same as CA Same as diagnostic CA
CC Contactor - Compressor C MMR Same as CA Same as diagnostic CA
Cd Contactor - Compressor D MMR Same as CA Same as diagnostic CA
d7 Over Voltage MAR Pre-start and a. Line voltage above +10% of nominal.
Any Circuit(s) (Must hold = +10% of nominal.
Energized Must trip = +15% of nominal.)
To Next Page
Loading...
Need help?
General
