Panasonic U-8ME1E81 Service Manual page 43

11. Alarm Information
11. Alarm Information
11-3. Pressure Sensor Failure
This system contains 2 types of pressure sensors: a high-pressure sensor and a low-pressure sensor.
11-3-1. High-Pressure Sensor Failure
When the high-pressure sensor becomes an electrical open-circuit or a short-circuit conditions, and a broken
wiring, short-circuit or poor connection to the PCB in the high-pressure sensor circuit for 30 seconds or leaves the
valve close.
When the high-pressure sensor detected over 3.6MPa continuously for 30 minutes while outdoor units stopped.
When the high-pressure sensor detected over 3.6MPa while outdoor units were operating.
Alarm display
11-3-2. Low-Pressure Sensor Failure
When the low-pressure sensor becomes an electrical open-circuit or a short-circuit conditions, and a broken wiring,
short-circuit or poor connection to the PCB in the low-pressure sensor circuit for 30 seconds.
Alarm display
11-4. High Pressure Protection and Low Pressure Protection
11-4-1. Abnormal High Pressure
The high-pressure switch works when it detects 3.65MPa or more.
If one of the high-pressure switches works, whole outdoor units stop and then restart.
If the high-pressure switch works after the system starts for 4 times, an alarm occurs.
Alarm display
11-4-2. Abnormal Low-Pressure
In the following conditions, an alarm occurs.
When all outdoor units stop in cooling mode and low-pressure sensor detects 0.16MPa or lower, and this condition
continues for 60 minutes, alarm occurs.
When an outdoor unit stops in heating mode regardless of system operation and low-pressure sensor detects
0.16MPa or lower, and this condition continues for 60 minutes, an alarm occurs.
If the following condition occurs after the system starts for 5 times, alarm occurs.
The low-pressure sensor detects 0.06MPa or lower, and this condition continues for 2 minutes.
When the compressor 1 accumulated operation time is within 10 hours, the low-pressure sensor detects 0.05MPa
or lower, and this condition continues for 10 seconds.
The low-pressure sensor detects 0.02MPa or lower.
Alarm display
The compressor doesn't start when low-pressure detects 0.16MPa or less.
High-pressure sensor failure
F16
Low-pressure sensor failure
F17
High-pressure cut-off
P04
Low-pressure cut-off
H06
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2WAY SYSTEM
2WAY SYSTEM
Control Functions-Outdoor Unit
Control Functions-Outdoor Unit
1