Bosch AHUW036A2 Service Manual page 27

2.13.2 Error code 53
Display code Title
53 Communication
PCB(Heater)
-->PCB(Inverter)
Table 28 Error code 53
Check point
1. Check the input power AC 230V
2. Check that the communication wires are correctly connected. Adjust
the connection of wire confirm the wire of "Live", "Neutral".
3. Check the resistance between communication line and GND (normal:
over 2M).
4. Check that the connector for communication is correctly connected.
5. Make sure you have connected to the communication line soldering
(if you do not connect by soldering, a communication error (CH05/
CH53) occurs by noise)
2.14 Error code 54
Display
code Title Cause of error
54 Open and • Prevention
reverse of phase
phase error unbalace and
prevention
of reverse
rotation of
constant -
rate
compressor
Table 29 Error code 54
A
1
2
3
Fig. 24 Error code 54 diagnosis and countermeasure flow chart
[A] Items for checking
[B] Sub-items for checking
[1] Installation
[2] Fuse damage (R and S phases)
[3] Inverter PCB
[4] Checking N-phase
[5] Checking for power phase loss
[6] Checking for open and reverse phase
[7] AC load
Split ODU – 6 720 817 722 (2015/06)
Cause of error
• Poor communication
Check point & Normal
condition
1. Main power wiring fault
B
4 5
6
7
6 720 817 722-34.1I
Error handling instructions for Split outdoor unit
Check point & Normal condition
1. Power input AC 230V
2. The connector for transmission is disconnected
3. The connection wires are miss-connected
4. The communication line is shorted at GND
5. Transmission circuit of PCB (inverter) is abnormal
6. Transmission circuit of PCB (heater) is abnormal
2.15 Error code 60
Display
code Title Cause of error
60 PCB • EEPROM
(inverter) access error
and main and check
EEPROM sum error
check sum
error
Table 30 Error code 60
Is EEPROM insertion No ->
normal?
Yes
Is PCB assembly 1 No ->
normal?
Yes
Is main PCB assembly 1 No ->
normal?
Yes
• Recheck power and
installation condition
Table 31 Error diagnosis and countermeasure chart
Check point
▶ Check the EEPROM check sum and direction
Check point & Normal
condition
1. EEPROM contact defect /
wrong insertion
2. Different EEPROM
version
3. ODU inverter and main
PCB assembly 1 damage
1. Check EEPROM insert
direction / connection
condition
2. Check EEPROM check sum
-->Replace if abnormality is found
1. Replace PCB assembly 1
1. Replace main PCB assembly 1
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