Carrier AquaEdge 19DV Operation And Troubleshooting page 36

ALARM DESCRIPTION OF
CODE ALARM TEXT
Alm-253 Protective Limit - High
Discharge Temp
Protective Limit - High
Alm-255
Motor Temperature
Protective Limit - High
Alm-256
Bearing Temperature
Alm-257 Protective Limit - High
Condenser Pressure
Protective Limit - Spare
Alm-258
Safety Device
Protective Limit -
Alm-259 Excessive Compressor
Surge
Protective Limit -
Alm-260 Compressor Start Relay
Start failure
Alm-261 Protective Limit -
Evaporator Frozen
Alm-263 Protective Limit - Invalid
Diffuser Config
Table 17 — PIC6 Alarm Codes* (cont)
CRITERION FOR TRIP
If compressor discharge temperature
sensor is in the range
AND
Compressor discharge temp > 167F (For
legacy chiller, this value is 220F)
If motor temperature sensor is in the
range
AND
If any of the Compressor motor winding
temp >220F
For 19DV chiller, if all of the bearing
temperature sensors are in the range
AND
{
If any of the other Compressor bearing
temp > tb_trip3
}
If condenser pressure sensor is in the
range
AND
{
COND_P > COND Pressure Cutout (it is
Cond Press Cutout Low Press for low
pressure condenser configuration and
Cond Press Cutout High Press for high
pressrue condenser configuration)
}
If the spare safety input in IOB3 goes to
CLOSED
If SURGE COUNTS exceed 4 within a
SURGE TIME PERIOD on the condition
that guide vane and VFD and HGBP
cannot be acted for surge protection
OR
If SURGE PROTECTION COUNTS
exceed 20 within a SURGE TIME
PERIOD.If vfd_opt is enabled, then VFD
speed should be maximum (cannot
moveable) before trip this alarm.
if START_OK is still not TRUE after 2
minute compressor start relay energized Manual
If evaporator refrigerant temperature and
evaporator pressure sensor is in the
range
AND
{If the less of evaporator refrigerant
temperature and the saturated
temperature is less than evaporator
refrigerant trip point plus 1 degree F}
This alarm is also effective on
pumpdown/lockout"
Diffuser configuration is invalid
ALARM RESET ACTION TAKEN BY THE
METHOD CONTROL
Unit shuts down. Alarm
Manual
relay turns on.
Unit shuts down. Alarm
Manual
relay turns on.
Unit shuts down. Alarm
Manual
relay turns on.
Unit shuts down. Alarm
Manual
relay turns on.
Unit shuts down. Alarm
Manual
relay turns on.
Unit shuts down. Alarm
Manual
relay turns on.
Unit shuts down. Alarm
relay turns on.
Unit shuts down. Alarm
Manual
relay turns on.
Unit shuts down. Alarm
Automatic
relay turns on.
36
POSSIBLE CAUSE
Check for closed compressor
discharge isolation valve. Check if
chiller was operating in surge
conditions. Check COMP
DISCHARGE TEMP sensor resistance
or voltage drop. Check for proper wiring
to IOB connectors. Check for proper
condenser flow and temperature.
Check for fouled tubes, plugged water
strainers, or non-condensable in the
condenser. Check for COMP
DISCHARGE TEMP > 220 deg F.
Check for proper inlet guide vane and
optional diffuser actuator operation.
Check COMP MOTOR WINDING
TEMP accuracy and wiring to IOB.
Check COMP BEARING TEMP
sensors accuracy and wiring to IOB. .
This fault can result from excessive
operation at low load with low water
flow to the evaporator or condenser.
Check CONDENSER PRESSURE.
Check for high Condenser Water
temperatures, low water flow, fouled
tubes. Check for division plate/gasket
bypass or plugged condenser water
strainers. Check for noncondensables
in condenser. Check CONDENSER
PRESSURE transducer wiring and
accuracy to IOB . Configure COND
PRESS OVERRIDE in configuration
screen. This Alarm is not caused by the
High Condenser Pressure Switch.
Spare safety input has been closed
Five SURGE PROTECTION COUNTS
occurred within SURGE TIME
PERIOD. VFD Only: Surge prevention
alarm declared when ACTUAL VFD
SPEED is at least 90%. Check for high
condenser water temperatures, low
water flow, fouled tubes. Check
CONDENSER APPROACH. Check
condenser water strainers. Check for
division plate/gasket bypass. Check for
noncondensables in condenser. Check
surge prevention parameters in
OPTIONS screen. Compare cooling
tower control settings and performance
against design/selection temperatures
across the entire operating range of the
chiller. Check EVAPORATOR
APPROACH and chilled water flow.
Check motor starter 1M contactor
wiring Check ISM current sensors
Check CALC EVAP SAT TEMP, EVAP
REFRIG LIQUID TEMP, and EVAP
REFRIG TRIPPOINT. Check for proper
refrigerant charge. Check float valve
operation. Confirm that optional
refrigerant liquid line isolation valve is
open. Check for proper Chilled Water
flow and temperature. Confirm that
condenser water enters bottom row of
condenser tubes first, reversed
condenser water flow may cause
refrigerant to stack in the condenser.
Check EVAPORATOR PRESSURE
transducer and EVAP REFRIG LIQUID
TEMP sensor. Check for evaporator
water box division plate gasket bypass.
Check for fouled tubes.
Check SRD configurations