Midea MIV V4+ Mini Service Manual page 28

MIV V4+ Mini DC Inverter R410A (220V, 8 kW)
① Indoor/outdoor communication malfunction
Indoor / outdoor communication alfunction
Short circuit or open circuit of
communication wire P, Q and E
OK
Irregular connection of
communication
(causing E2 error and
indefinite variation or
reduction in the number
of indoor units)
There are other electronic
magnetic interference
sources nearby, such as
transformer, strong solar
light and so on
Communication
is too long, exceeding
specified value.
Chip fault, or chip foot sheds off, or chip is
inverted (correct mode is semicircular bent
alignment)
Mainboard error:
For example,
getting wet
26
Exist
Repetition of address code to indoor unit
Some indoor units are not power-on
(reduction in the number of indoor units)
wire
Communication wire is not in serial
connection (such as star connection or
parallel connection)
Communication wires does not be
OK
separated from Power wires, causing
interference
Exist
OK
wire
Exceed
OK
OK
Check communication wire
(generally measuring resistance
between P, Q and E)
Rule out interference source,
or add shielding and filters
Make proper regulation or
strengthen signal
Reinstall chip, or install other
chip with same model on the
Error
faulty unit, to check whether
there is something wrong with
chip.
OK
Replace
mainboard
DM12-01.01.05en
Outdoor units