23.9.5 Overriding WECS or its parts
In serious WECS problems the functionality of the system can be
reduced into minimum by turning off the MCU. This can be done
by pressing the MCU power switch into OFF position. After this
action only minimum safety functionality of the Relay Module is
available i.e. backup overspeed trip, backup lube oil pressure
shutdown, optional shutdown and emergency stop. Turning off
the MCU will naturally stop the Modbus communication to the
external alarm system. On the LDU all values will be shown
inverted, because they are no more updated. It is anyhow possible
to operate the engine with local start, stop and reset buttons. Also
backup instrumentation is still operational.
Note!
There is no automatic check for start conditions, when the MCU
is turned off. Therefore operator must personally ensure, that
all start conditions are met and it is safe to start the engine.
Turning off the MCU does not give any help, if problems occur
with the Relay Module. In that case the only reliable way to solve
the problem is to replace the broken module with a spare Relay
Module.
If WECS problems are limited into one DCU or SMU, it is also
possible to turn off that DCU or SMU by disconnecting connector
31-34 on the SMU board. This way of working guarantees that
monitoring, safety and control functions needed for safe operation
of the engine are minimally influenced. All signals connected to
the disconnected DCU or SMU will give an alarm over Modbus.
If problems are limited to one signal or sensor only, it is possible
to disconnect the signal. The exact connection can be found from
the installation specific drawing “Wiring diagram - Distributed
units”. A sensor failure code will be indicated over Modbus for the
disconnected sensor.
Note!
Signals indicating sensor failure are ignored, when start con-
ditions are checked. Therefore operator must personally en-
sure, that disconnected signals are not in critical situation,
when the engine is started.
Note!
Initial reason for the problem should be investigated immedi-
ately and needed actions to cure the problem should be taken
as soon as possible. Once the problem is solved, the system
should be returned to a normal operation.
23
Instrumentation and Automation
32-200115/II
23-56
WÄRTSILÄ 32
Summary of Contents for PAAE051728
Page 4: ......
Page 18: ...Appendix B Welding Precautions 200640 00 6...
Page 26: ...01 Main Data Operating Data and General Design 32 200634 01 01 8 W RTSIL 32...
Page 60: ...Appendix A Environmental Hazards 200507 02A 10...
Page 68: ...Page 7 7 Document No 4V92A0645 Rev j...
Page 84: ...03 Start Stop and Operation 32 200402 04 03 12 W RTSIL 32...
Page 98: ...04 Maintenance Schedule 32 200623 01 04 14 W RTSIL 32...
Page 154: ...07 Tightening Torques and Use of Hydraulic Tools 32 200643 01 07 30 W RTSIL 32...
Page 162: ...08 Operating Troubles Emergency Operation 32 200402 01 08 8 W RTSIL 32...
Page 164: ...Specific Installation Data 2005 01 09 2...
Page 178: ...10 Engine Block with Bearings Oil Sump and Cylinder Liner 32 200150 10 14 W RTSIL 32 34SG...
Page 216: ...Appendix A Testing of cylinder tightness 32 200142 A 4 W rtsil 20 32 34...
Page 226: ...13 Camshaft Driving Gear 32 200546 02 13 10 W RTSIL 32...
Page 254: ...15 Turbocharging and Air Cooling 32 200549 10 15 20 W RTSIL 32...
Page 274: ...16 Injection System 32 200627 01 16 20 W RTSIL 32...
Page 280: ...Fuel System 32 200508 07 17 6 W RTSIL 32...
Page 314: ...19 Cooling Water System 32 200050 19 14 W RTSIL 32...
Page 394: ...23 Instrumentation and Automation 32 200115 II 23 60 W RTSIL 32...