Haier MRV 5-RC VP1-112B Service Manual page 213

Failure code
Outdoor Indoor unit LED status
digital
display tube:
114-4, 5
Indoor wired
Outdoor unit LED status
controller:
72
1. Model
MRV 5-RC series
2. Abnormity detection method
◆ Check the power supply
voltage is too low, resulting
in reduced voltage after
rectification;
◆ Check if the PTC is in
normal conditions;
◆ Check if the cabinet is
correctly wired.
3. Abnormity confirmation
conditions
When the power voltage
<DC283V, fault and alarm.
Voltage> DC283V, the
motor built-in control panel
automatically restored
4. Possible causes
◆ Incorrect wiring may result
in under voltage alarm;
◆ PTC or SCR damage may
result in under voltage;
◆ Low power voltage may
result in under voltage.
Normal
Failure diagnosis and troubleshooting
Diagnosis
Check if the supply voltage is normal
and the cabinet is wired correctly.
Check if the PTC and SCR is
damaged.
When the fan running, testing the
DC voltage between DC + (red
line), DC- (white line) if it less
than 283?
Check the rectifier bridge,
reactor, electrolytic capacitor
of inverter main circuit
LED5 Failure description:
Fan motor module DC BUS under voltage
20 times
LED1 LED2
Normal
N
Y
N
Y
Y
N
210
Troubleshooting
Adjust the supply voltage or
rewire the cabinet in accordance
with circuit diagram.
Replace the compressor module
Replace the fan motor