19 Series Carrier®
SmartVu
TM
–
Controls IOM
Check compressor discharge temperature
sensor wiring and accuracy to IOB
connector.
Check for excessive starts.
Check COMP DISCHARGE ALERT
setting.
ALM-233 Prestart
Failure - Low
Refrigerant Temp
Check Evaporator Pressure, Evap Sat
Rrefig Temp, and Evap Rrefig Liquid
Temp.
Check Evaporator Pressure transducer
and Evaporator Refrigerant Liquid
Temperature sensor wiring and accuracy.
Check for low chilled water supply
temperatures.
Check refrigerant charge.
Check REFRIG OVERRIDE DELTA T and
EVAP REFRIG TRIPPOINT in
configuration screen.
ALM-234 Prestart
Failure - Low Line
Voltage
Check ACTUAL LINE VOLTAGE.
Check UNDERVOLTAGE THRESHOLD in
ISM_CONF screen.
Check voltage supply. Check wiring to
ISM J3-L1, J3-L2, and J3-L3.
Check voltage transformers and switch
gear.
Consult power utility if voltage is low.
ALM-235 Prestart
Failure - High Line
Voltage
Check ACTUAL LINE VOLTAGE.
Check OVERVOLTAGE THRESHOLD in
ISM_CONF screen.
Check voltage supply.
Check voltage transformers and switch
gear.
Consult power utility if voltage is high.
ALM-236 Guide Vane 1
Calibration Not
Completed
Guide Vane 1 Calibration in Quick
Calibration screen.
Check guide vane actuator feedback
potentiometer and wiring to IOB connector.
ALM-234 Prestart
Failure – No Power
Supply
Check the Power Request Output and the
Power Feedback input status.
ALM-238 Guide Vane 2
Calibration Not
Completed
Guide Vane 2 Calibration in Quick
Calibration screen.
Check guide vane actuator feedback
potentiometer and wiring to IOB connector.
ALM-239 Envelope
Control Valve
Calibration Not
Completed
Envelope control valve Calibration in Quick
Calibration screen.
Check EC valve feedback potentiometer
and wiring to IOB connector.
Alm-240 Damper
Valve Calibration Not
Completed
Tested on control test mode or prestart
check, if Damper calibration is failed
ALM-250 Protective
Limit - Oil Pressure
Difference Failure
Check oil pump
Check oil filter
Check oil pump wiring
ALM-251 Protective
Limit - Low Chilled
Water Flow
Perform Chilled Water pump test in Quick
Test screen. Check Evap Refrig Liquid
Temp and Leaving CHILLED WATER
temperature sensor accuracy and wiring to
IOB.
Check chilled water valves, pumps, and
strainers. Check EVAP REFRIG
TRIPPOINT, EVAP APPROACH ALERT,