Carrier X-POWER Series - Page 147

Carrier service manual R410A DC Inverter Series
Troubleshooting 165
4.2 E2: Indoor units and master unit communication error (Only display on master unit, all the ODU
in standby)
E
2
:
Indoor units and master
unit communication error
Communication wires P, Q, E are short
circuit or disconnected (Measure the
resistance among P, Q and E, the normal
resistance between P and Q is 120Ω)
Reconnect the communication
wires
Communication wires are not
connected in line shape
The communication wires are interfered
by high voltage power (voltage over
208-230V is high voltage power)
Communication wires are close to
electromagnetic interference source.
Such as transfer, strong fluorescent
lamp, etc.
Remove the interference source, or
use device to filter out the interference
The length of communication wire is
over 1200m
Adjust the wire length to less than
1200m or strengthen the signal
Outdoor main control board is
damaged
Yes
Yes
Yes
Connect the communication wires
in line shape
No
No
No
No
No
Yes
Ensure the communication wires and
high voltage wires do not twining
Yes
Replace outdoor main control board