Airwell AWAU-YDV1010-H13, Service Manual

Page: 155 / 187

153
Failure code
Outdoor
digital
display tube:
75-0, 4
Indoor wired
controller:
4B
Indoor unit LED status
LED5 Failure description:
Pressure difference between high and low
pressure too low failure 20 times
Outdoor unit LED status
LED1 LED2
Normal Normal
1. Model Diagnosis and troubleshooting
Flow Logic III series
Diagnosis Troubleshooting
2. Abnormity detection method
◆
Check if the difference
between high and low pressure
of system exceeds 0.4MPa after
start and before failure alarm;
◆
Check if the unit lack of
refrigerant.
◆
Check the four-way valve of
unit for normal switching and
free from backflow.
◆
Check if the detection value
of high/low pressure sensor is
correct.
◆
Check if the unit is beyond
the operation range.
3. Abnormity confirmation
conditions
75-0: Pd-Ps≤0.1Mpa within 1min
upon the INV compressor starts.
75-4: Pd-Ps≤0.4Mpa lasts for
3min.
4. Possible causes
◆
The detection value of
high/low pressure sensor is
incorrect;
◆
The refrigerant in the system
is insufficient;
◆
The four-way valve cannot
be switched normally or with
backflow.
The power module cannot
drive the compressor operating
normally;
◆
The inverter compressor is
with serious inter deterioration,
which makes it difficult to form
difference between high and
low pressure.
◆
The operation environment
is beyond the allowed range.
Check if the high-low pressure
difference of system exceeds 0.4MPa
after start and before failure alarm;
Check if the refrigerant in the system
is with leakage or insufficient.
Check if the detection value of low
pressure sensor is correct.
If the four-way valve of outdoor unit is
with backflow and if the suction pipe
filter of compressor is blocked.
Check if it operates normally
after replacing a normal driver
module.
if the allowed operation range is exceeded.
Use the unit in accordance with
its allowed operation range.
Replace it correctly by after-sales
personnel on site and ensure the
refrigerant is enough.
Rectify it correctly by after-sales
personnel on site.
Check if the corresponding pressure
sensor is intersected with another
compressor, especially for a double
compressor system.
Troubleshoot and replace it correctly
by after-sales personnel on site.
[Note]: Check if the suction pipe
filter of compressor is blocked, when
the discharging temperature rises
obviously.
R e p l a c e t h e d r i v e r m o d u l e
correctly.
Replace the inverter compressor
if the high-low pressure difference
cannot reach 0.4MPa above before
failure alarm.
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