Protection Functions; Overheating Protection For Indoor Unit - GE ASYW09CRAWA Service Manual

Indoor Unit
The PCB will signal the louver stepper motor to open the to
either a stationary position or one of several oscillating
modes.
As the louver opens, the PCB will power up the fan motor,
The PCB controls the fan speed if set to the Auto position,
or signals the motor to operate at a fixed speed previously
set.the speed of the fan motor.
Temperature Sensors
Use same language here as used in the heating section,
inserting dry mode in place of heat or heating.
Communication
The indoor and outdoor unit units communicate via the wire
connected to terminal 3 of each unit.A splice or break in this
wire will cause a communication error.
Outdoor Unit
Upon a request for dry mode, the PCB applies power to the
fan motor outdoor and compressor.Depending on system
cycling, there may be up to a 3 minute wait period before the
compressor and outdoor fan start.
WARNING: Do not measure compressor voltages as damage
to the meter may result.
The PCB also controls the position of the
Temperature Sensors
Four sensors provide temperature information to the PCB for
control of the system during dry mode.
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 discharge sensor provides the temperature sensed at the
discharge pipe of the compressor.
To stop dry mode, press the power button to turn the system
Defrost
The PCB monitors the temperature difference between the
ambient and defrost sensors as the coil becomes colder.
A defrost cycle will initiate when this difference grows beyond
an acceptable level. To enter a defrost cycle, the compressor
must have accumulated 10 minutes of run time and 45 minutes
of run time since the last defrost.
refrigerant to the evaporator coil.
SEQUENCE of OPERATION
When a call for defrost initiates, the compressor slowly ramps
down, then runs for 30 seconds at a very low speed.
1 minute from the call for defrost, the 4WV switches to cooling,
all fans stop, and the EEV changes to a mid-range. Once these
functions are completed, the compressor ramps up to a high
speed.
When the outdoor coil reaches more than 45 degrees for 60
seconds, or more than 54 degrees for 30 seconds, the defrost
cycle will terminate. The compressor then returns to a very
low speed for 1 minute while all components return to the
heating mode.
The defrost cycle is terminated automatically after 10 minutes
if the coil does not reach the specified temperatures.

Protection Functions

1. High Temperature
The discharge (exhaust) sensor monitors the temperature
of the refrigerant leaving the compressor. Compressor
speed will either increase, decrease, or the compressor may
stop in response to temperatures reported by the discharge
sensor. Refer to the table below.
Abnormal stop
230
°F
Decreasing the frequency rapidly (1HZ/1second)
212
°F
Decreasing the frequency slowly (1HZ/10 seconds)
209
°F
The frequency doesn't change
199
°F
Increasing the frequency (1HZ/10 seconds)
194
°F
Increasing the frequency (1HZ/1second)

2. Overheating protection for indoor unit

coil sensor monitors temperature at the coil surface
according to the table below.
Overheating protection for indoor unit
Increasing slowly Prohibiting increasing
09K
48℃/118℉ 51℃/124℉
12K
48℃/118℉ 51℃/124℉
18K 48℃/118℉ 53℃/127℉
24K
48℃/118℉ 53℃/127℉
Decreasing slowly Decreasing rapidly Compressor stop
56℃/133℉ 59℃/138℉ 63℃/145℉
56℃/133℉ 59℃/138℉ 63℃/145℉
56℃/133℉ 60℃/140℉ 63℃/145℉
56℃/133℉ 60℃/140℉ 63℃/145℉
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