Service Manual
45
Installation and Maintenance
2. High pressure protection (E1)
Start
Are the display board and mainboard
connected tightly?
Are the OVC terminal on the mainboard
connected well with the high pressure switch
on the complete unit ?
Is the wiring of high pressure switch loosened? Is the high
pressure switch broken or poorly contacted?
Connect the display board with the mainboard well
Is the refrigerant superabundant?
Is there poor heat exchange? (Including filth
blockage of heat exchanger and bad radiating
environment )
Is the supply voltage normal? (If it is a 3-phase unit, high
pressure protection may be caused by overcurrent
protection due to this)
Are the air
intake and air discharge at indoor / outdoor heat
exchanger smooth?
Is there filth blockage on the filter or on the
heat exchanger fins of indoor / outdoor unit?
Are the gas valve and liquid valve for
outdoor unit opened completely?
yes
yes
no
no
no
no
yes
yes
no
Replace the mainboard
yes
End
no
Malfunction is eliminated.
no
Connect the OVC terminal on the main board with the high
pressure switch on the complete unit well
no
Malfunction is eliminated.
no
If the wire of high pressure switch is loosened, please
connect the wires according to the circuit diagram.
If the high pressure switch is broken or poorly contacted,
please replace it.
yes
Malfunction is eliminated.
no
Adjust the volume of refrigerant according to the
requirement of the system
yes
Malfunction is eliminated.
no
Adjust the unit to improve the heat exchange of unit
yes
Malfunction is eliminated.
no
The ambient temperature exceeds normal operation range;
high pressure protection will occur once turning on the unit,
which is a normal phenomenon
yes
Malfunction is eliminated.
no
The normal fluctuation is within 10% of the rated voltage on
the nameplate
no
Malfunction is eliminated.
Adjust the system to make the air intake and air discharge of
indoor and outdoor heat exchangers smooth
no
Malfunction is eliminated.
no
Remove the blockage.
yes
Malfunction is eliminated.
Open the outdoor gas valve and liquid valve completely
no
Malfunction is eliminated.
no
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
no
no
Is the ambient temperature too high?
(If it is a 3-phase unit, high pressure protection may be caused
by overcurrent protection due to this)
