Panasonic U-20ME1E81, Service Manual

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2WAY SYSTEM
Trouble Diagnosis
6
4. 2WAY Alarm Codes
3WAY SYSTEM
Trouble Diagnosis
4. 3WAY Alarm Codes
H06 Alarm
Alarm code H06
Alarm meaning Abnormal decrease of low-pressure
Alarm conditions
Probable cause (1) Low-pressure sensor failure
(1) Low-pressure sensor failure
(1) Replacement of low-pressure sensor
(2) Correct malfunction of refrigerant cycle.
(2) Failure to open the service valve of the outdoor unit
(4) Insufficiency of refrigerant gas
(5) Refrigerant is accumulated in a state of stop mode of the outdoor units.
(2) Failure to open the service valve of the outdoor unit
(3) Clogged refrigerant circuit
(4) Insufficiency of refrigerant gas amount
(5) Refrigerant is accumulated into the stopped outdoor units.
Check
•
Correction
When replacing a low-pressure sensor, carry out after refrigerant recovering of outdoor unit.
Example
Low-pressure sensor detects lower than 0.06MPa continuously for 2 minutes or lower than 0.02MPa
for just a moment.
•
The alarm had occurred because of refrigerant insufficiency due to gas leak. •
The alarm had occurred when the liquid, suction and discharge tubes were clogged together. •
Check the sensor resistance value.
(Use a tester and measure the resistance between sensor No. 1 and No. 3)
• Connect a gauge to the low-pressure outlet and check for changes in the value disp l ayed by the
monitoring software, and for large deviation of the gauge pressure.
Resistance of less than 95k
Check the open/closed status of the service valve.
(3) Check for clogging of the refrigerant circuit.
When clogging in the refrigerant circuit occurs, refrigerant does not return to the compressor.
As a result, low-pressure may occasionally decrease abnormally.
When insufficiency of refrigerant charge amount or of refrigerant amount in the system caused by
gas leakage occurs, low-pressure may occasionally decrease abnormally.
Leakage of expansion valve and solenoid valve in the outdoor unit in stop mode, etc.
Solenoid valve, expansion valve, fleezing caused by contaminated water inside the circuit, etc.
Then check the following points:
indicates a short circuit or other trouble.
Resistance of 95k (low-pressure sensor pin 1-3) - 105k is normal.
Resistance of more than 105k indicates an open circuit or other trouble.
Open valve of outdoor unit.
Correct clogging.
•
•
Dissolve insufficiency of refrigerant gas
(Correction of gas leakage area, additional refrigerant, etc.)
•
When charging additionally because of refrigerant insufficiency, add each 500g of refrigerant
little by little.
SM830228-00̲3WAY ECO-i SYSTEM.in18 18 2013/03/16 18:25:21
SM830204-05_2WAY SYS.indb 20 2015/01/20 17:45:20