Panasonic U-8ME1E8E Service Manual page 48

13. Other Functions
13-3-3. Outdoor unit PCB LED indications in judgment mode
Judgment item
Judgment mode
Normal
Insuffi cient gas
Overcharge
Judgment not possible
When judgment mode is not engaged, the LED indicates the normal display (OFF), or else indicates alarms or
other information.
If the insufficient gas or overcharge judgment is not stable, then recover refrigerant a little at a time when the
overcharge display appears. End refrigerant adjustment when the normal or insufficient gas display appears.
13-3-4. Canceling judgment mode
When judgment mode is cancelled, the LED returns to the standard status display (OFF unless an alarm or other
event has occurred).
[1] Automatic cancel
Judgment mode is canceled automatically when 4 hours have passed after it was started.
[2] Forced cancel
Short-circuit the CHK pin while the judgment mode display is active in order to cancel judgment mode
<Reference>General Guidelines for Insufficient Gas and Overcharge
Judgment in automatic judgment mode can be problematic in some cases. Therefore, the following guidelines are
provided for general judgment of the refrigerant amount.
• Symptoms of insufficient gas
Cooling There is an indoor unit where the position of the electronic control valve is much higher (open
by 300 pulses or more) than it was at start, and the difference [E3 – E1] at that indoor unit is
operation
large (15 ℃ or more).
Heating There is an outdoor unit where the position of the electronic control valve is much higher (open
operation by 300 pulses or more) than it was at start, and the difference [Liquid temp. – Gas temp.] at
that outdoor unit is large (15 ℃ or more).
• Symptoms of overcharge
The high-pressure sensor temperature is 57 ℃ or higher, and the difference [Pressuresensor
Cooling
operation
temp. – Liquid temp.] at that outdoor unit is large (15 ℃ or more).
Heating There is an indoor unit where the position of the electronic control valve is much higher (open
operation by 300 pulses or more) than it was at start, and the difference [Pressuresensortemp. – E3] at
that indoor unit is large (25 ℃ or more).
These are only guidelines, therefore the judgment may vary depending on the installation conditions, load
characteristics, and other elements.
LED1 LED2
Blinking Blinking
ON ON
Blinking OFF
OFF Blinking
Blinking alternately
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Control Functions-Outdoor Unit
Recommended response
-
-
Charge with refrigerant a little at a time.
Recover refrigerant a little at a time.
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2WAY SYSTEM
1