2. Processes and functions
1
2
3
4
5
II - 7
SM830080
2-5
Freeze Prevention (Cooling)
Freeze Prevention keeps the indoor heat exchange coil from freezing. Freezing reduces
the efficiency of the unit, and frost build up on the coil blocks cool air circulation from the
indoor unit's fan.
Note: Freeze prevention is controlled by the temperature at the indoor heat
exchanger coil as sensed by either sensor E1 (located at the entrance
of the coil) or sensor E2 (located on the middle of the coil). Freeze
prevention cycle is controlled by the lower temperature sensed at either
of the two sensors.
Chart Explanations and notes
❑
This chart shows when the electronic expansion valve opens to regulate the temperature
of the indoor unit coil to prevent freezing.
❑
If the refrigerant control is not effective and the temperature continues to drop and stays
below 0°C for 2 minutes continuously, the control circuit stops the compressor. The
compressor does not start again until the temperature rises above 1°C.
The compressor stops for 3 minutes minimum.
Note: • When low fan speed is selected and the air conditioner is in cooling
operation at a low outdoor temperature of less than 10°C, the air
conditioner may automatically switch to medium fan speed.
• Cut the jumper wire (JP11) on the outdoor P.C.B. when the above
FMI control (L
➞
M) is not needed.
Fig. 8
(
°
C)
INDOOR UNIT
COIL TEMP.
ELECTRONIC
EXPANSION
VALVE SIGNAL
MIN. VALUE OF
EITHER E1 OR E2
1
3
–0.5
0
–0.5
COMPRESSOR
CONTINUOUS
DETECTION
FOR 2 MINUTES
MINIMUM 3
MINUTES
ON
ON
1563_M_S
OPEN (+60 step/30 sec)
OPEN (+60 step/30 sec)
FMI CONTROL
L
M
L
M
