Gree GMV6 DC Inverter VRF Units Service Manual
109
2.58 "E2" Protection in Case of Too Low Air Discharge Temperature
of Compressor
Fault display:
main board of outdoor unit, wired controller of indoor unit and receiver of indoor unit
display
Fault diagnosis:
When the difference between the air discharge temperature of compressor and the temperature at
the high pressure is below 10°C, the unit stops running to ensure safe operation.
Possible causes:
■ The compressor's temperature sensor for air discharge operates improperly;
■ The electronic expansio
n valve of indoor unit operates improperly in cooling mode;
■ The electronic expansion valve of outdoor unit operates improperly in heating mode;
■ Excessive refrigerant in the unit.
Troubleshooting:
Step 1:
Check whether the air discharge pipe and shell roof temperature sensor of each compressor
are installed firmly, and whether the protection sponge is fastened.
Then, check whether the resistance corresponding to each temperature is normal based on the
temperature - resistance table of temperature sensor. If not, replace the temperature sensor.
Step 2:
If the unit is in cooling mode:
First, inspect the indoor electronic expansion valve:
①
When the electronic expansion valve of the indoor unit is closed to 0PLS, if the temperature
difference between the inlet and outlet pipes of the indoor unit coil and the temperature at the
low pressure is less than 10°C, it indicates that the unit operates improperly.
Solution:
First, make sure that the EXV coil is connected properly, and then power off the unit. Power
on to reset the unit and check the resetting action. If unable to reset the unit, replace the coil or the main
board. If able to reset the unit normally despite the problem, replace the electronic expansion valve.
②
Check whether the electronic expansion valve of the indoor unit operates properly: If the
electronic expansion valve is open to 200PLS, the temperature of the outlet pipe of indoor unit
coil is smaller than that of the inlet pipe by over 1°C, and the difference between the discharge
temperature of the compressor or the shell roof temperature of the compressor and the high
pressure temperature is less than 10°C.
Solution:
First, make sure that the EXV coil is connected properly, and then power off the unit. Power
on to reset the unit and check the resetting action. If unable to reset the unit, replace the coil or the main
board. If able to reset the unit normally despite the problem, replace the electronic expansion valve.
Next, inspect the outdoor subcooler electronic expansion valve:
After confirming that the EXV coil is connected properly, power off the unit. Then power on to reset
the unit and check the resetting action.
Step 3:
If the unit is in heating mode, check the electronic expansion valve of the outdoor unit first.
After confirming that the EXV coil is connected properly, power off the unit. Then power on to reset
the unit and check the resetting action. If unable to reset the unit, replace the coil or the main board. If
Summary of Contents for GMV6 Series
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