AUX ASW-H09B5B4/FAR3DI-C3, Service Manual

Page: 38 / 101

35
(7) E5(5E) -Indoor Unit and Outdoor Unit communication error
Explanation of
error
Cause: The frequency converter needs Indoor Unit and Outdoor Unit
communication.When the communication cannot be reached, the
Indoor Unit and Outdoor Units will indicate “Indoor Unit and Outdoor
Unit communication error”. Only “Indoor Unit main PCB, connecting
cable and Outdoor Unit main PCB” are related to communication;
but sometimes the communication error will be indicated when the
Outdoor Unit has no power and the Indoor Unit cannot connect with
the Outdoor Unit due to other errors, then such situation shall be
distinguished from “pure communication error” and treated in a
different way.
Inspection path: Check if the Outdoor Unit can power on and work
(normally, the indicator light will turn off after lighting for several
seconds, relay picks up, and PTC won’t heat seriously)
1. Can power on and work: Are the Indoor Unit and Outdoor Unit
matched→is the phase sequence of connecting wires of Indoor Unit
and Outdoor Units correct (the live wire of the Indoor Unit connects
with that of the Outdoor Unit, the null wire of the Indoor Unit connects
with that of the Outdoor Unit)→Connecting wires touched
well→Indoor Unit main PCB replacement→Outdoor Unit main PCB
replacement
2. Cannot power on and work: Can AC 220V be delivered to the
terminal block of the Outdoor Unit→Can the bridge rectifier and
module panel generate DC 310V→Can the Outdoor Unit main PCB
generate a low voltage power supply of DC 5V→Does the Outdoor
Unit main PCB show the status of periodical reset.
Tools required
for inspection
Multimeter, Indoor Unit main PCB in normal condition
Frequent
problematic part
Connecting wire phase sequence and contact, Indoor Unit main PCB,
Outdoor Unit main PCB, module panel
Inspection
procedure and
key points
1. Firstly, the IDU and the ODU should be matched and connected
properly.
2. Observe the Outdoor Unit main PCB, turn on the air conditioner,
three lights are all lighted up then off and the relay pulls in. If not, it is
power supply problem.
3. Connect the black signal line S to terminal N of ODU. Turn on the
A/C, if "E5" is still reported, the Outdoor Unit main PCB need to be
replaced. If "E5" is still reported at this time, go to step 4.
4. Change a new Indoor Unit main PCB, if the error code E5 remains,
then the problem should be on the Outdoor Unit main PCB.