1. Specifications
1
2
3
4
Section
– 31 –
SM830076
2. Processes and functions
2-5
Freeze Prevention (Cooling)
Freeze Prevention keeps the indoor heat exchange coil from freezing. Freezing reduces the
efficiency of the unit, and frost buildup on the coil blocks cool air circulation from the indoor
unit's fan.
Fig. 8
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 refrigerant control 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 30°F for 2 minutes continuously, the control circuit stops the compressor. The
compressor does not start again until the temperature rises above 34°F.
The compressor stops for 3 minutes minimum.
(
°
F)
INDOOR UNIT
TEMP.
ELECTRONIC REF.
CONTROL
VALVE SIGNAL
MIN. VALUE OF
EITHER E1 OR E2
34
32
31
30
COMPRESSOR
CONTINUOUS
DETECTION
FOR 2 MINUTES
MINIMUM 3
MINUTES
OPEN
ON
ON
1138_THS_I
OPEN
