Haier MRV5-H - Page 122

119
Failure code
Outdoor
digital
display tube:
75-0
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
MRV 5-HR 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
◆
Check if the detection value
of high/low pressure sensor is
correct.
◆
Check if the unit is beyond
the operation range.
conditions
upon the INV compressor starts.
3min.
4. Possible causes
◆
The detection value of
high/low pressure sensor is
incorrect;
◆
The refrigerant in the system
◆
The four-way valve cannot
be switched normally or with
The power module cannot
drive the compressor operating
normally;
◆
The inverter compressor is
with serious inter deterioration,
difference between high and
low pressure.
◆
The operation environment
is beyond the allowed range.
Check i f the high-low pressure
difference of system exceeds 0.4MPa
after start and before failure alarm;
Check if the refrigerant in the system
Check if the detection value of low
pressure sensor is correct.
If the four-way valve of outdoor unit is
with b ackflow and if the suction pipe
Check i f it o perates 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 c orrectly b y after-sale s
personnel o n site and e nsure the
refrigerant is enough.
Rectify i t correctly by a fter-sale s
personnel on site.
Check if the corresponding pressure
sensor i s intersected w ith anothe r
compressor, especially for a double
compressor system.
Troubleshoot and replace it correctly
by after-sales personnel on site.
[Note]: Check i f the suction pipe
filter of compressor is b locked, when
the discharging temperature rise s
obviously.
Replace the driver m odul e
correctly.
Replace t he i nverter compresso r
if t he high-low pressure d ifference
cannot reach 0.4MPa above before
failure alarm.
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