Haier MRV 5-RC VP1-112B Service Manual page 193

Failure code
Outdoor
Indoor unit LED status
digital
display tube:
39-0
Indoor wired
Outdoor unit LED status
controller:
27
1. Model
MRV 5-RC series
2. Abnormity detection method
◆ Check if the low pressure of
system is below 0.06MPa before
failure alarm;
◆ Check if the unit lack of
refrigerant.
◆ Check if the pipelines on the
low pressure side or liquid side
of the unit are blocked;
◆ Check if the detection value
of low pressure sensor is correct.
◆ Check if the unit is beyond
the operation range.
3. Abnormity confirmation
conditions
Alarm to shut down if the
followings are detected for
5min: cooling: Ps< 0.10Mpa;
heating: Ps< 0.05Mpa; oil
return: Ps<0.03Mpa after the
compressor operates. (except
residual operation)
4. Possible causes
◆ The detection value of low
pressure sensor is incorrect;
◆ The refrigerant in the system
is insufficient or the system is
with air leakage;
◆ The pipelines on the low
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 low pressure
of system is below 0.05MPa
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.
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:
Low pressure sensor Ps too low protection
20 times
LED1 LED2
Normal
Y
Y
N
N
Y
Y
N
N
Y
190
Troubleshooting
Replace it correctly by after-
sales personnel on site and
ensure the refrigerant is enough.
Rectify it correctly by after-sales
personnel on site.
Troubleshoot and rectify it correctly
by after-sales personnel on site.
[Note]: Check if all stop valves can
be turned on and if the air-returning
pipe filter of compressor is blocked.
Check if all the electronic
expansion valves of the indoor unit
can be turned on normally.