221
Failure code
Outdoor
digital
display tube:
125-0, 1
Indoor wired
controller:
7D
Indoor unit LED status
LED5 Failure description:
Compressor frequency un-match
20 times
Outdoor unit LED status
LED1 LED2
Normal Normal
1. Model Failure diagnosis and troubleshooting
MRV 5-RC series
Diagnosis Troubleshooting
2. Abnormity detection method
◆
Check if the communication
circuits of power module and
inverter board are securely
inserted and connected.
◆
Check if the power module
is well.
◆
Check if the inverter board
is well.
3. Abnormity conrmation
conditions
(current frequency ≥ INV
target frequency +3Hz) or
(target frequency ≥0 && actual
frequency =0) for continuous 5
minutes
4. Possible causes
◆
The power module and
inverter board are connected
loosely, which results in
detection failure of compressor
rotation speed.
◆
The power module is
damaged.
Y
Whether the power supply voltage is
too low or uctuating signicantly
N
Adjust the power supply.
Y
Check if the electrical box connect
correctly
Reconnect or re-fix it in
accordance with wiring
diagram.
N
Check if the inverter module is
normal
N
Replace the inverter module
Y
Compressor winding resistance,
insulation is normal
N
Replace the compressor