4-6 Discharge Temperature Control (Cooling and Heating)
This function prevents the compressor motor from burn out by overheating.
Discharge temperature is sensed by TH8 (discharge gas sensor).
When the temperature rises above 95°C the electronic refrigerant control valve opens at 50 steps/30
seconds until the temperature falls below 93°C.
During HEATING operation, when the temperature rises above 105°C, the control circuit stops the outdoor
fan motor until the temperature falls below 90°C. Please note that this control does not function during
COOLING operation.
For both COOLING and HEATING modes, if the temperature reaches 115°C (135°C for 48 type) the
operation shuts down and alarm P3 appears on the remote controller.
The outdoor fan speed is controlled on discharge temp. at heating mode.
4-7 Auto. Mode for Automatic Heating/Cooling Switching
When the AUTO mode is selected, the microprocessor calculates the difference between the set
temperature and the room temperature, and automatically switches to the COOLING or HEATING mode to
maintain the desired temperature.
Room temp.
>
Set temp.
COOLING
=
Room temp.
<
Set temp.
HEATING
This means that if the room temperature is higher or equal to the set temperature, COOLING operation
starts. If the room temperature is lower than the set temperature, HEATING operation starts.
Chart Summary and Explanations
Fig. 11
OUTDOOR
FAN SPEED
DISCHARGE GAS
TEMP. ( °
115
105
95
93
90
85
COMPRESSOR
ELECTRONIC
EXPANSION VALVE
(DISCHARGE TEMP.)
TRIP IS OPERATED.
H or M
L
1566_M_S
OPEN
OPEN
H or M
ON
20
