OUT-87
DUAL, TRIPLE, POKER DC Inverter : 3. Outdoor Unitis & Troubleshooting
Multi Liberty
DC Inverter
The display shows
“
P2”.
Intervention of Low Pressure protection.
Hypothesis 2:
Malfunction of Low Pressure Sensor.
Hypothesis 4:
Refrigerant leak on refrigerant circuit.
Hypothesis 3:
Is outdoor temperature too low?
Hypothesis 1:
Check wirings and the right connection of
Low Pressure Sensor (L_PRO) to Control PCB. Are they
OK?
Disconnect the Sensor’s connector, then check if normal
operation of system is restored.
YES
YES
YES
YES
NO
NO
NO
Check if there are refrigerant leaks on system,
by high pressure nitrogen gas. If leak is
remarkable, a hissing sound near the leak
point will be heard. In case of a small leak,
please use an electronic gas leak detector -
specifically designed for R410A - to find it.
Connect the pressure gauge to a check joint of Outdoor
Unit, and verify if pressure gauge shows a pressure value
lower than 0.15MPa.
Measure low pressure value on the circuit: is it OK?
YES
NO
NO
• Check if refrigerant circuit is obstructed.
• Does 4-way valve operate properly?
• Do expansion valves (EXV) operate properly?
Intervention of low pressure protection
(*)
[Models HCKU 816 X4, HCKU 1066 X4 only]
P 2
• Empty the refrigerant (by recovering it).
Eliminate the obstruction along the circuit,
carry out the vacuum procedure and the
weighed out recharge of R410A.
• Replace 4-way valve or EXV valve which
present eventual eventual operation anomalies.
Restore.
Replace L_PRO Sensor.
System stop.
Replace Outdoor Unit’s main PCB.
Outline of protection function
• Troubleshooting flowcharts, referred to Protection Codes displayed on Outdoor Unit:
Protection Code on Outdoor Unit
(*)
Intervention value of L_PRO: 0.03Mpa
Reactivation value of L_PRO: 0.10MPa.