Midea MHC-96HWD1N1(A) Service Manual page 40

R410A Full DC Inverter Split Duct Type Technical Manual
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E2: Indoor & outdoor unit communication error
E2: Indoor units and outdoor
unit communication error
Communication wires P, Q, E are
short circuit or disconnected (Measure
the resistance among P Q and E, the
normal resistance is 120Ω)
No
Communication
connected in line shape
No
The communication wires are interfered
by high voltage power (voltage over
220V is high voltage power)
No
Communication wires are close to
electromagnetic interference source.
Such as transfer, strong fluorescent
lamp, etc.
No
The length of communication wire is
over 1200m
No
Outdoor main control
board is damaged
39
wires are not
Yes Reconnect the communication
wires
Yes Connect the communication wires
in line shape
Yes
Ensure the communication wires and
high voltage wires do not twining
Yes Remove the interference source, or
use device to filter out the interference
Yes
Adjust the wire length to less than
1200m or strengthen the signal
Replace the outdoor
main control board
MCAC-UTSM-201503