Sinclair SDV5 Series Service Manual page 46

2.3 E2: Communication error between indoor and outdoor unit (For all models)
2.3.1 Digital display output
E2
2.3.2 Description
 Communication error between indoor and outdoor unit.
 The system stops running.
 Error code is displayed on the outdoor unit PCB.
2.3.3 Trigger / recover condition
 Trigger condition: Indoor units and the outdoor unit cannot communicate for 2 minutes after the system is powered
on for 20 minutes.
 Recover condition: Communication go back to normal.
 Reset method: Resume automatically.
2.3.4 Possible causes
 Communication wires between indoor and outdoor units not connected properly.
 Indoor unit power supply abnormal.
 Loosened wiring within electric control box.
 Interference from high voltage wires or other sources of electromagnetic radiation.
 Communication wire too long.
 Damaged main PCB or electric control box communication terminals block.
 Communication wire break or poor contact for reasons (such as rat beat, or bond and connection).
2.3.5 Procedure
Communication wires P Q E have short
circuited or disconnected
Communication wires P Q E are not
connected in a daisy chain
IDU power supply is abnormal
Wires between outdoor main PCB and
electric control box communication
terminals block are loose
Interference from high voltage (220V or
E2
1
No
No
No
No
higher) wires
No
Yes
Reconnect the communication wires
Connect the communication wires in a
Yes
daisy chain
Yes
Ensure normal power supply
Yes
Ensure the wires are connected properly
Ensure the communication wires and
Yes
high voltage wires are separated
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