WinGD X72-B - Page 465

Indication on LDU Possible cause Procedure
AE3802C
NOx sensor fails to measure NOx at
turbocharger outlet.
NOx-Sensor alarm signal is not in
measuring mode (1 Hz) or in cali-
bration mode (2 Hz).
Status bit for hardware signal failure:
NOx sensor.
For Hardware signal failure:
•
Re-establish the cabling
X31-3/4/5 to MCM E70.
For Alarm signal failure:
•
Re-establish the cabling X12-1/2
to MCM E70.
•
Replace the faulty sensor if re-
quired.
Tab 10-71 External system failure
Indication on LDU Possible cause Procedure
Auxiliary blower #1 failure The SCR control system is unable to
receive the auxiliary blower #1 op-
erating signal in specified time inter-
val.
Parameter: PAR_AuxBI_FailDelay
•
Do a check of the auxiliary blow-
er control box.
Auxiliary blower #2 failure The SCR control system is unable to
receive the auxiliary blower #2 op-
erating signal in specified time inter-
val.
Parameter: PAR_AuxBI_FailDelay
•
Do a check of the auxiliary blow-
er control box.
External SCR common alarm SCR system sends common alarm.
•
Do a check of the external SCR
control system.
Tab 10-72 Emergency bypass failure
Indication on LDU Possible cause Procedure
Emergency bypass Emergency bypass command on
one of the E70, E71, E73 or PCS.
•
If it is not possible to activate
emergency bypass manually, re-
establish the cabling.
Tab 10-73 Bypass switch activation failure
Indication on LDU Possible cause Procedure
SCR - S2 - Emergency bypass
switch E71
Bypass switch signal from the relat-
ed control unit is active.
•
If it is not possible to activate by-
pass switch manually, re-estab-
lish the cabling.
SCR - S3 - Emergency bypass
switch E72
SCR - Emergency bypass
switch PCS
SCR - S1 - Emergency bypass
switch E70
X72-B
AA00-0000-00AAD-410A-A
Operation Manual LP SCR - Alarm failure troubleshooting
Winterthur Gas & Diesel Ltd.
- 465 - Issue 003 2021-12