“E3” System Low Pressure Protection - Gree UML600H/A-MP Service Manual

GREE
Troubleshooting：
pressure connecting to the
the cut-off valve of ODU is
ODU/IDU short circuit or are
Check if the swing board
of IDU opened completely?
Is the electronic expansion valve
of ODU/IDU operating normally?
Is system pipeline blocked?
(27) "E3" system low pressure protection
Error display: ODU mainboard, IDU displays
Applicable model: all models.
Error judgment condition and method：Detect the suction pressure of compressor through
pressure sensor of low pressur, when the pressure value is below -41°C, the system will stop operation.
E1 system high pressure
protection
Is the system high
No
pressure gage over
4.2MPa?
Yes
Check if
No
completely opened?
Yes
No
Is the panel of ODU
covered completely?
Yes
Is the air inlet of
No
there any barriers?
Yes
No
Check the fan operation
of ODU/IDU is normal?
Yes
No
Yes
No
Yes
Yes
Check is the fin
of ODU/IDU dirty and
blocked?
No
Yes
Is ambient outdoor
temperature over 52℃?
No
Yes
No
Every time after releasing 1kg of refrigerant
Refrigerant and operating for 1.5h consecutively, observe
charging quantity
is too much
Duct type Ducted Type Split Air-Conditioner Units
Yes
Test if the high pressure
switch is normal
No
Open the cut-off valve of ODU completely
Reinstall the panel of ODU
Clear the barriers and avoid the short circuit in air inlet
No
Check if the input
Replace the main board
signals of fan normal?
Yes
Check the swing motor and input signals
Check the electronic expansion valve and main board
Clean the fin
Protect normally, no treatment
Re-weld the pipeline
the system to see if there's protection.
Repeat the operation as above until no
protection occurs any more.
.
95
Replace the main board of
ODU
Replace the high pressure
switch
Replace the motor