Carrier EverFRESH Operation, Service And Parts Manual page 29

AL980 Fresh Air Valve (EA) Fault
Cause: When the system energizes the EverFRESH Air Valve (EA) solenoid and membrane pressure does
not drop 40 psi, the alarm is triggered. The alarm triggers OFF when membrane pressure transducer
(MPT) pressure drop is more than 40 psi when EA is opened.
Component EverFRESH Air Valve (EA) Solenoid
Troubleshooting Run a P20 test to verify mechanical and electrical performance of the
Component ML5 Controller
Troubleshooting Access function code Cd74 to perform an ML5 self-diagnostic test.
AL981 Water Drain Valve (WDV) Fault
Cause: When the system energizes the Water Drain Valve (WDV) and membrane pressure does not drop 40
psi, the alarm is triggered. The alarm triggers OFF when membrane pressure transducer (MPT)
pressure drop is more than 40 psi when the EverFRESH Air Valve (EA) is opened.
Component Water Drain Valve (WDV)
Troubleshooting Inspect WDV bowl and outlet piping for obstructions, clean components.
Component ML5 Controller
Troubleshooting Access function code Cd74 to perform an ML5 self-diagnostic test.
AL982 CO2 Injection Fault
Cause: If unit is configured with the CO2 injection option, this alarm is triggered when Cd76 is set to "On" to
enable CO2 injection and CO2 is less than the CO2 setpoint by 0.5% and IPT < 20 PSIG.
Component CO2 Supply
Troubleshooting Verify CO2 supply is available and supplied at the recommended pressure.
Component CO2 Injection Port Schrader Valve
Troubleshooting If proper pressure is available at the CO2 injection supply port, verify that the
Component CO2 Injection Solenoid
Troubleshooting Run a P20 test to evaluate the solenoid and replace if test fails.
AL983 CO2 Injection Pressure Transducer Fault
Cause: If unit is equipped with the CO2 injection option, this alarm is triggered when Cd76 is set to "On" to
enable CO2 injection and volts are not in the range of 0.5 to 4.95 VDC.
Component CO2 Injection Pressure Transducer (IPT)
Troubleshooting From function code Cd74, run a controller self-diagnostic test. Evaluate
Table 4–1 Alarm Indications and Descriptions
solenoid.
If the electrical test fails, replace the valve.
If the mechanical test fails, check for obstructions blocking system flow.
Remove obstructions. If it still fails, replace the valve.
Run P20 test to verify mechanical and electrical performance of solenoid.
If the electrical test fails, replace the valve.
If the mechanical test fails, check for obstructions blocking system flow.
Remove obstructions. If it still fails, replace the valve.
Schrader valve is being depressed by the supply hose properly to allow flow.
results to see if there is a controller or transducer issue. If there is a sensor
issue, or if the test passes, change the transducer.
4–5 T-374