Carrier AquaEdge 19DV Controls Operation And Troubleshooting page 34

DESCRIPTION
ALARM CODE
OF ALARM TEXT
Protective Limit -
ALM-254 Low Evap
Refrigerant Temp
Protective Limit -
ALM-255 High Motor
Temperature
Protective Limit -
ALM-256 High Bearing
Temperature
Protective Limit -
ALM-257 High Condenser
Pressure
Protective Limit -
ALM-258 Spare Safety
Device
Protective Limit -
Excessive
ALM-259
Compressor
Surge
Protective Limit -
Compressor Start
ALM-260
Relay Start
failure
Protective Limit -
ALM-261 Evaporator
Frozen
Protective Limit -
ALM-262 Condenser
Frozen
Protective Limit -
ALM-263 Invalid Diffuser
Config
Table 16 — PIC6 Alarm Codes* (cont)
ACTION TAKEN BY
RESET TYPE
THE CONTROL
Unit shuts down.
Manual
Alarm relay turns on.
Unit shuts down.
Manual
Alarm relay turns on.
Unit shuts down.
Manual
Alarm relay turns on.
Unit shuts down.
Manual
Alarm relay turns on.
Unit shuts down.
Manual
Alarm relay turns on.
Unit shuts down.
Manual
Alarm relay turns on.
Unit shuts down.
Manual
Alarm relay turns on.
Unit shuts down.
Manual
Alarm relay turns on.
Unit shuts down.
Manual
Alarm relay turns on.
Unit shuts down.
Manual Alarm relay turns on. Check SRD configurations
POSSIBLE CAUSE
Check for proper refrigerant charge.
Check float valve operation. Check for closed condenser liquid line
isolation valve. If problem occurs at high load, check for low condenser
pressure which causes inadequate refrigerant flow through condenser
flasc orifices. 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 and LEAVING CHILLED WATER
sensors. Check for division plate gasket bypass. Check for fouled tubes.
Check pressure transducer and temperature sensor wiring to the IOB.
Check COMP MOTOR WINDING TEMP accuracy and wiring to IOB.
Check oil heater for proper operation, confirm that oil heater is de-
energized when compressor is running. Check for low oil level, partially
closed oil line isolation valves, or clogged oil filter. Check oil cooler
refrigerant thermal expansion valves, confirm that expansion valve
bulbs are secured to the oil lines and insulated. 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. Very high discharge and volute temperatures may increase
the oil sump temperature. Elevated sump temperature may result from
an excessively high oil level reaching the bottom of the bull gear causing
it to churn the oil.
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.
The Cond Sat refrig Temp is less than the Condenser Freeze Point.
Check Condenser Freeze Point in configuration. Condenser water too
cold or chiller shut down with brine below 32 deg F in cooler so
equalization temperature in chiller approached 32 deg F. Check
CONDENSER PRESSURE transducer and wiring to IOB. Check
Condenser Water Temperature sensors and wiring to IOB. Check
refrigerant charge.
34