Haier MRV 5-RC VP1-112B Service Manual page 194

Failure code
Outdoor Indoor unit LED status
digital
display tube:
39-1
Indoor wired
Outdoor unit LED status
controller:
27
1. Model
MRV 5-RC series
2. Abnormity detection method
◆ Check if the operating
compression ratio of system is
above 8 before failure alarm;
◆ Check if the unit lack of
refrigerant.
◆ Check if the pipelines on the
low pressure side or liquid side
are blocked;
◆ 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
Alarm to shut down if the
compression ratio ε>8.0 is
detected for continuous 5min
after the compressor operates;
alarm to shut down if the
compression ratio ε>9.0 or
ε>8.5 when cooling or heating
for 1min separately.
4. Possible causes
◆ The detection value of high/
low pressure sensor is incorrect;
◆ The refrigerant in the system
is insufficient or the system is
with air leakage;
◆ The pipelines on the high
pressure side or liquid side of
the unit are blocked;
◆ The outdoor unit cannot be
turned on normally due to failure
to open electronic expansion of
outdoor heat exchanger when
heating;
◆ The operation environment is
beyond the allowed range.
Normal
Diagnosis and troubleshooting
Diagnosis
Check if the system operating
compression ratio is above 8
before failure alarm.
Check if the refrigerant in the system
is with leakage or insufficient.
Check if the detection value of high-
low pressure sensor is correct.
Check if the pipelines on the
low pressure side or liquid
side of the unit are blocked.
Check if the allowed operation
range is exceeded.
Use the unit in accordance with
its allowed operation range.
LED5 Failure description:
Compressor ratio ε too high protection
20 times
LED1 LED2
Normal
Y
Y
N
N
Y
Y
N
N
Y
191
Troubleshooting
Use the unit in accordance with
its allowed operation range.
Rectify it correctly by after-sales
personnel on site.
Troubleshoot and rectify it correctly
by after-sales personnel on site.
[Note]: Simultaneously, check if all
stop valves can be turned on.
C h e c k i f a l l t h e e l e c t r o n i c
expansion valves of the indoor unit
can be turned on normally.