Haier MRV 5-RC VP1-112B Service Manual page 183

Failure code
Outdoor Indoor unit LED status
digital
display tube:
26-0, 1, 2
Indoor wired
Outdoor unit LED status
controller:
1A
1. Model
MRV 5-RC series
2. Abnormity detection method
◆ Grounded short-circuit
of communication wire, or
disconnected communication
wire P and Q;
◆ Incorrect wiring of
communication wire P and Q;
◆ Uniform indoor unit power
supply, and partial indoor unit
being powered off.
◆ Larger interference and
unstable communication signal.
◆ Failure in PCB of indoor and
outdoor unit results in unstable
communication.
3. Abnormity confirmation
conditions
It is not detected that there
is indoor unit connection for
200 rounds continuously; it
is detected that the number
of indoor units is less than
set number for 270 seconds
continuously; it is detected that
the number of indoor units is
more than set number for 170
seconds continuously.
4. Possible causes
Poor communication wire:
short circuit and disconnection;
Incorrect wiring of
communication wire P and Q P
and Q;
Poor PCB results poor
communication;
Larger interference of normal
communication.
Normal
Failure diagnosis and troubleshooting
Diagnosis
Check if the communication
wire of outdoor unit is shorted
Check if the communication wire
of outdoor unit is disconnected
Check if the communication
wire P and Q of indoor and
outdoor unit is incorrect
Check if there is same indoor unit No.
Check if the computer board
communication port of indoor
and outdoor unit is correct
Check if there is interference source
Replace indoor or outdoor computer board
LED5 Failure description:
Communication between indoor unit and
20 times outdoor unit failure
LED1 LED2
Normal
Y
N
Y
N
Y
N
Y
N
N
Y
Y
N
180
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.
Adjust it correctly by after-
sales personnel on site.
Adjust it correctly by after-
sales personnel on site.
Eliminate the interference
source.