33/61
ESI Outdoor Unit Installation Instruction
05.2018
Manufacturer reserves the right to change at any time for specifications or designs without notice and incurring obligations.
Display
Low pressure protection in cooling
mode
or
1.Error definition:
P2: The detected low pressure in cooling mode is less than 24.5psig.
E2: System locks up when P2 has occurred six times within 3 hours.
2.Possible causes:
Service valves are closed.
Dirty air filter or indoor heat exchanger
Outside temperature is lower than 23F (i.e. low ambient temperature cooling)
Too little refrigerant in the system.
Defective indoor R410A TXV.
G signal is lost resulting in indoor unit FAN=OFF.
Damaged low pressure sensor.
Damaged main control board.
Note
:
Connect a pressure gauge to gas stop valve, compare the difference between the gauged
pressure and the transduced one by low pressure sensor.
NO
YES
NO
Replace the low pressure
sensor
Can the pressure transduce measure properly according to
Low
Pressure Sensor Voltage Characteristics C*.
YES
Correct specific point
Check visible parts for the system
1) Closed service valve; 2) Clogged indoor heat exchanger; 3) Dirty air filter; 4) Fan is not operating
Satisfy any contents above.
NO
Replace the main control board
YES
Is the low pressure close to
24.5psig before protection?
YES
Check whether the TXV of indoor unit is dirty plugging.
Use AUTO charge mode to check whether there is too little refrigerant in the system.
Replace the main control board if the protection happens again with proper refrigerant amount.
Whether the low pressure has
been evacuated?
NO