Heat Mode; Call To Terminate Cooling; Cold Air Proof Operation; Freeze Protection - GE ASYW09CRAWA Service Manual

Temperature Sensors
Four temperature sensors provide temperature information
to the PCB for control of the system.
The ambient sensor provides the temperature of the air
drawn into the condenser coil of the outdoor unit.
The defrost sensor provides the temperature sensed at the
output of the condenser coil.
The suction line sensor provides the temperature sensed at
the incoming suction line pipe.
The compressor discharge sensor provides the temperature
sensed at the discharge pipe of the compressor.

Call to Terminate Cooling

The system will terminate cooling when the room
temperature is not more than two degrees below the set
temperature. The compressor stops, while the outdoor
fan continues running for another 60 seconds.
The indoor fan motor and louver will continue operating after
cooling has been terminated.
To stop cool mode, press the power button to turn the system
off, or change to another mode.

Freeze Protection

To prevent the indoor coil from becoming too cold during
low load or high humidity days, and when the compressor
has been running for 10 seconds with the coil temperature
at or below 32 degrees, the compressor will stop
automatically. The indoor fan will continue to run, using
room air to warm the coil. When the coil temperature
has reached 45 degrees for 3 minutes or more, the
compressor will start to resume the cooling operation.
The temperature control range in heating mode is 60°F - 86°F.

Heat Mode

Overview
The temperature set at the remote control and the room
ambient temperature sensor will determine if a call for
heat is needed. If justified, a temperature compensation
adjustment is automatically added to the
operating parameter and the call is communicated from the
indoor unit to the outdoor unit.
The louver will open using a stepper motor. The indoor
fan will not operate until the coil warms sufficiently
to keep cold air from circulating in the room.
The outdoor unit will shift the 4-way valve to the heating
and determine the position of the EEV and speed
(frequency) of the compressor. There can be adelay of up to
3 minutes before the outdoor fan and compressor start.
(Tr = room temperature Ts = set temperature)
operates in cold air proof operation
If Tr > Ts+, the outdoor unit turns off and the indoor fan
will circulate any residual heat remaining in the coil.
If Tr < Ts+, the outdoor unit will restart and the indoor fan
operates in cold air proof operation.
The speed of the indoor fan can be controlled manually by
the user or automatically by the system. The speed can be
changed between HIGH, MEDIUM, and LOW. The
predetermined conditions for automatic control are as
follows:
High Speed: Tr < Ts
Low Speed: Tr > Ts + 4°F

Cold Air Proof Operation

At initial start of heat mode, indoor blower will not be turned
on until the coil has reached a minimum temperature. This
delay period can be up to 3 minutes, depending on the
difference between the room and the set temperature.
This period usually takes 30 seconds to 3
minutes depending on the outdoor ambient temperature.
Heat start temp 1
Heat start temp
Heat start temp
Heat start temp
The outdoor unit sensors; ambient,defrost, suction line, and
compressor discharge, used in conjunction with the indoor
sensors,
ambient and coil, provide information to the outdoor control
board to monitor the coil and regulate the frequency of
the compressor, EEV positioning, and outdoor fan speed to
achieve the desired room temperature.
When heating has been satisfied, the outdoor unit compressor
will turn off first and followed by the outdoor fan. The
4-way valve will de-energize 2 minutes after the compressor
stops.
The indoor unit fan will continue to run at a very low speed
until any heat remaining in the coil is circulated into the room.
If the system detects a malfunction, it may shut down or
show an error code on the indoor unit display board and/or
outdoor unit main board LED.
SEQUENCE of OPERATION
Set speed
Low speed
2
Light speed
3
Fan/off
4
Fan/off
K eep the high
speed. The fan
doesn' t stop
PAGE 21