Midea Aqua Tempo Super II Series Service Manual page 55

Aqua Tempo Super II
4.4.4 Procedure
Communication wires P Q E have short
circuited, disconnected or are
Communication wires P Q E are not
connected in a daisy chain
Wires between outdoor main PCB and
electric control box communication
terminals block are loose
Interference from high voltage (220V or
Communication wires are close to a
source of electromagnetic radiation such
as transformer or strong fluorescent lamp
Damaged control box communication
The length of communication wire is over
Replace main PCB or user interface
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.
Communication wiring has polarity. Ensure that the P wire is connected to P terminals and the Q wire is connected to Q terminals.
54
E2
1
misconnected
No
No
No
higher) wires
No
No
terminals block
No
1200m
No
Yes
Reconnect the communication wires
Connect the communication wires in a
Yes
daisy chain
Yes
Ensure the wires are connected properly
Ensure the communication wires and
Yes
high voltage wires are separated
Remove the source of interference, or
Yes
add additional shielding to the
communication wires
Replacing electric control box
Yes
communication terminals block resolves
the error
Reduce the wire length to less than
Yes
1200mm or strengthen the signal
201709