Midea ATOM MDV-V56WDHN1(AtB)

Atom B Series VRF 50/60Hz
51
Part
6
-
Diagnosis and Troubleshooting
2.4.5 Procedure
E2
Communication wires P Q E have short
circuited or disconnected
1
Yes
Reconnect the communication wires
No
Communication wires P Q E are not
connected in a daisy chain
Yes
Connect the communication wires in a
daisy chain
No
IDU power supply is abnormal
Yes
Ensure normal power supply
No
Wires between outdoor main PCB and
electric control box communication
terminals block are loose
Yes
Ensure the wires are connected properly
No
Interference from high voltage (220V or
higher) wires
Yes
Ensure the communication wires and
high voltage wires are separated
No
Communication wires are close to a source
of electromagnetic radiation such as
transformer or strong fluorescent lamp
Yes
Remove the source of interference, or
add additional shielding to the
communication wires
No
The length of communication wire is over
1200m
Yes
Reduce the wire length to less than
1200m or strengthen the signal
No
Clear all indoor unit address by setting
switch S1 and then automatically
addressing indoor unit by setting S1 too
2
,
repower on to confirm whether fault clear
Yes
Some indoor unit address repeat,
maintain to use
No
Replacing outdoor main PCB resolves the
error
No
Replace electric control box
communication terminals block
Notes:
1. Measure the resistance among P, Q and E. The normal resistance between P and Q is 120Ω, between P and E is infinite, between Q and E is infinite.
2. S1 switch setting as below table; for every times setting, you need to repower on to make the switch dial function works.