E5(5E) -Internal And External Communication Error - Toyotomi KURO Mini Service Manual

(7) E5(5E) -Internal and external communication error

Cause:
communication.When the communication cannot be reached, the internal and
external units will indicate "internal and external communication error". Only
"main internal control panel, connecting cable and main external control
panel" are related to communication; but sometimes the communication
error will be indicated when the external unit has no power and the internal
unit cannot connect with the external 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 external unit can power on and work
(normally, the indicator light will turn off after lighting for several seconds,
Explanation of
relay picks up, and PTC won't heat seriously)
error
1. Can power on and work: Are the internal unit and external unit
matched→is the phase sequence of connecting wires of internal and external
units correct (the live wire of the internal unit connects with that of the
external unit, the null wire of the internal unit connects with that of the
external unit)→Connecting wires touched well→Main internal control panel
replacement→Main external control panel replacement
2. Cannot power on and work: Can AC 220V be delivered to the terminal
block of the external unit→Can the bridge rectifier and module panel
generate DC 310V→Can the main external control panel generate a low
voltage power supply of DC 5V→Does the main external control panel show
the status of periodical reset.
Tools required
Multimeter, main internal control panel in normal condition
for inspection
Frequent Connecting wire phase sequence and contact, main internal control panel,
problematic part
main external control panel, module panel
1. Firstly, the IDU and the ODU should be matched and connected properly.
2. Observe the main external control panel, turn on the air conditioner, three
lights are all lighted up then off and the relay pulls in. If not, it is power
Inspection
supply problem.
procedure and 3. Connect the black signal line S to terminal N of ODU. Turn on the A/C, if
"E5" is still reported, the main external control panel need to be replaced. If
key points
"E5" is still reported at this time, go to step 4.
4. Change a new main internal control panel, if the error code E5 remains,
then the problem should be on the main external control panel.
When the external unit not power on: If the internal terminal board does
not transmit 220V power, replace the main internal control panel; if the
external terminal board has 220V power, first check if (fuse, reactor and
bridge rectifier) are normal. There is still something wrong, replace the whole
set of external control unit; for the control unit composed of several function
Special attention
boards, try disconnecting the weak-current data wires among several control
boards and then power the external unit on, if the main control panel can be
powered on and initialized successfully, then it's the module panel problems;
if the main external control panel still cannot be powered on and initialized,
replace the main external control panel.
The frequency converter
7
needs internal and external