Bergen B35:40, Project Manual

Page: 65 / 74

Safety, Control and Monitoring System
Page 2 : 9
3.02
, Gas
0211 BC
Engine Control Cabinet (ECC)
This cabinet includes Safety PLC, Control PLC ,
Electronic governor and interface to monitoring
system.
The ECC is wall mounted and recommended placed
in the control room / air conditioned area. Environ-
ment class is IP42 and max. ambient temp. is 50 °C.
The cabinets measurements in mm is 2000/800/600
(h/w/d). Cables to enter cabinet through cabinet
bottom.
The 24V distribution cabinet is recommended
placed as near as possible to the ECC.
Safety System
The Safety System is based on a PLC system and will
manly consist of a CPU and connected IO.
The Safety System is responsible for the stop of
engine caused by auto stops
All signals connected to the Safety System are hard-
wired. Where applicable - wire break detection is im-
plemented. The Safety System has separate sensors
from the rest of the control system.
When an alarm situation is detected the Safety
System will activate relays to closed the double
block and bleed valves for closing fuel supply; turn
of the ignition system, signal stop to the speed gov-
ernor and activate the stop solenoid to mechanically
force the fuel rack to fully closed position.
The Safety System will signal auto stop to the Start
and Sequence System for correct action of all
auxiliary system. An MPI communication link to the
Monitoring system is used to signal the Safety Sys-
tem status to the ships monitoring system.
Start and Sequence Control (SSC)
The SSC system is based on a PLC system and will
mainly consist of a CPU and communicating
modules.
SSC is responsible for the following tasks:
•
Start/stop of engine, including start interlock
function and start failures.
• Start/stop of priming pump (lubrication)
• Start/stop of pre-heater pump
• Start/stop of after cooling pump
• Standby pump functions (if applicable)
Interface to propeller control/PMS and
electronic governor
• Control ignition together with the ignition
module
• Deal with alarm data from the knock detection
system
• Handle all auto stop functions as back up.
• Temperature PID control
Set points for auto stops can be parameterized with-
in the Safety and Sequence Control system PLC.
Note: Not all functions will be active/used in all applications.
Functions are to be enabled by parameters (in PLC data block).
No programming will be necessary to change parameters.
The SSC system will consist off a CPU. The CPU will
connect to the remote IO by using Profinet. Directly
connected to the CPU there will be RS232 communi-
cation module communicating with the speed
controller giving the SSC system access to process
and diagnostic data from the Closed loop control
system. A RS485 Modbus communication link is
present to allow data from the Ignition system to be
available to the SSC system.
The SSC system will function as an auto stop back-up
unit if the Safety System does not function properly
meaning that all auto stops are also handled by the
SSC system.
A Modbus link to the Monitoring system is used to
extract status information for the ship monitoring
system.
The SSC system handles temperature PID control
for charge air temperature, HT water temperature
(if applicable) and lubrication oil temperature (if
applicable) internally in the PLC.
Closed Loop Control System
The engine is equipped with an electronic governor.
The governor will handle the following functions:
•
Engine speed control
• Load control:
- Load sharing/balancing with other prime
movers (similar or different kind)
• Turbo wastegate/ VTG Control (Variable turbine
geometry)
• Air Throttle control
• Gas pressure regulation