Panasonic S-36PU1E5A Technical Data & Service Manual page 488

6) Cooling Freeze Prevention Control
The following control is performed during cooling operations (including dry mode operation), in accordance
with whichever of the indoor heat exchanger temperatures (E1 or E2) is lower. (See the chart below.)
(1) If the temperature remains in the "J" zone (decreasing operation frequency and thermostat OFF zone) for
6 minutes, the operating frequency of the compressor is decreased.
The operation frequency is amended every 30 seconds as long as the temperature is in this zone.
(2) If the temperature is in the "K" zone (operating frequency increase prevention zone), the operating
frequency of the compressor is maintained.
(3) If the temperature is in the "H" zone (operating frequency restriction zone) and the ambient temperature
is less than 32°C, the maximum operating frequency of the compressor is limited in accordance with the
indoor unit fan speed.
(4) If the temperature is in the "I" zone (normal operation zone), normal operations are performed.
(5) If the temperature is continuously in the "J" zone with the compressor's operating frequency reaches "0",
then temperature A, which is temperature for changing from the "J" zone to the "H" zone, is raised from
5°C to 8°C, and operation continues with the thermostat off until the temperature enters the "H" zone.
min. (E1 , E2)
°C
22
4
17
5
2
7) Discharge Temperature Control
The following control is performed to prevent the discharge temperature from rising abnormally in order to protect
the inverter compressor.
In accordance with the temperature of the discharge sensor TD, such controls are performed as to limiting the
increase of inverter frequency, decreasing it or halting operation of the compressor.
TD (discharge)
°C
111
106
100
95
90
* If the discharge temperature exceeds 111°C, operations of the compressor are halted and restarted after 3
minutes.
If this start/stop activity is repeated 4 times, the alarm "P03" (abnormal discharge temperature) occurs.
I (normal operation zone)
H (operating frequency restriction zone)
A
K (operating frequency increase prevention zone)
J (decreasing operation frequency and thermostat OFF zone)
Outdoor unit operation halted
Frequency decreased
Frequency increases prevented
Frequency increased slower than normal
Normal (no control)
4-14