Midea V4+R Series - 4.4.4 Procedure

V4+R VRF 50/60Hz
56 201608
Midea V4+R Series Service Manual
Procedure 4.4.4
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
2
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
3
Yes
Ensure the wires are connected properly
No
Interference from high voltage (220V or
higher) wires
4
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
Replacing outdoor main PCB resolves the
error
No
Replace electric control box
communication terminals block
5
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. Refer
to the V4+R Engineering Data Book, Part 3, 9.3 “Communication Wiring”.
2. Refer to the V4+R Engineering Data Book, Part 3, 9.3 “Communication Wiring”.
3. Refer to the V4+R Engineering Data Book, Part 2, 5 “Wiring Diagrams”.
4. Refer to the V4+R Engineering Data Book, Part 3, 9.1 “General” for required separation distances between communication wiring and power wiring.
5. Refer to Figures 5-1.2 and 5-1.4 in Part 5, 1 “Outdoor Unit Electric Control Box Layout”.