Bosch ODU Split 6 - Error Code 23: DC Link Voltage High;Low; Error Code 23 Diagnosis and Countermeasure Flow Chart

Error handling instructions for Split outdoor unit
Split ODU – 6 720 817 722 (2015/06)
11
2.5 Error code 23
2.5.1 Error diagnosis and countermeasure flow chart
Check Point
1. Check the WCN_P(L), P(N) connection condition ate the main PCB
(heater). Refer to wiring diagram.
2. Check the DC link voltage at no operation of compressor (280V).
3. Check the DC link voltage at operation of compressor (340V).
4. Check the DC link sensing signal (AHBW**6AO): 2.4~2.8V
(Graphic 12).
5. Check the DC link sensing signal (AHBW**8AO): 0.4~0.6V
(Graphic 13).
ODU Split 4, 6, 8
Fig. 11 ODU Split 4, 6, 8
Display
code
Title Cause of error
Check point & Normal
condition
23 DC link High
/ Low
voltage
• DC link
voltage is
above
420Vdc
• DC link
voltage is
below
140Vdc
1. Check CN_(L), CN_(N)
connection
2. Check input voltage
3. Check PCB DC link
voltage sensor parts
Table 9 Error code 23
Is input voltage normal? No -> 1. Check power input voltage
Yes
Is inverter PCB
assembly 1 power
connection normal?
No ->
1. Check power connection state
Yes
Is PCB (Inverter)
normal?
No -> 1. Replace PCB assembly 1
Yes
Recheck power and
installation condition
Table 10 Error diagnosis and countermeasure chart
IN/I
GND
Vdc
6 720 817 722-09.1I