Haier MRV 5-RC VP1-112B Service Manual page 181

Failure code
Indoor unit LED status
Outdoor
digital display
tube: 24-0, 1, 2
Indoor wired
controller: Outdoor unit LED status
18
1. Model
MRV 5-RC series
2. Abnormity detection method
◆ Check if the sensor
connection is normal;
◆ Check if resistance
characteristic of the sensor is
normal;
◆ Check if the temperature
loop acquired by the PCB is
normal.
3. Abnormity confirmation
conditions
It is detected that the AD value
is below 11 (open circuit) or
above 1012 (short circuit) for
60 seconds continuously, when
Ta≤-10°C, no alarm is given;
when ET≤-10°C, no alarm is
given within 5 minutes.
4. Possible causes
◆ The connection of sensor is
not secure;
◆ The sensor is broken;
◆ The oil temperature sensor
is with resistance drift;
◆ The temperature acquired
by PCB is not accurate.
Normal
Failure diagnosis and troubleshooting
Diagnosis
Check if the corresponding
connector of sensor is normal
C h e c k i f r e s i s t a n c e
characteristic of the sensor
is normal
Check if the temperature
l o o p a c q u i r e d b y t h e
computer board is normal
LED5 Failure description:
Oil temperature sensor:
20 times Th, Toil1 and Toil2 failure
LED1 LED2
Normal
N
Y
N
Y
Y
178
Troubleshooting
Replace it correctly by after-
sales personnel on site.
Replace it correctly by after-
sales personnel on site.
Replace it correctly by after-
sales personnel on site.