Rolls-Royce Helicon X3, User Manual

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System Description
Page 14 of 16 Doc. No.: 13S000411
Revision: A
Copyright © 2010 Rolls-Royce plc
4.3 RPM Control
The RPM Control function system controls the speed signal to the frequency converter
for electrical drives or the engine governor for diesel or gas engines.
4.3.1 RPM Control Electric Drive Motor
The RPM Control system includes selection of different operational modes:
• Separate Mode
• Combined Mode
Selection between modes is possible by means of push buttons. RPM Control can be
managed from engine control room only or from additional control panels.
4.3.2 External RPM Control
External RPM order signals from system as DP/Joystick/Auxiliary systems can be
connected to the rpm controller.
The external rpm signal are checked against adjustable preset limits. Any error
conditions on the rpm input signal will initiate a warning to the alarm plant and an error
message will be displayed on the control panel.
4.3.3 RPM Order Output
The output signal from the controller is scaled to meet the actuator signal range from idle
to full rpm, and then fed to external governor, IP converter or frequency converter. The
output will follow a linear curve between idle and full rpm order.
The RPM output rate of change is adjustable and can be adapted to the engine/frequency
converter reversing speed from idle to full rpm (increasing order) and vice versa
(decreasing order).
4.3.4 Propeller/Shaft RPM Indication
The propeller/shaft RPM indicators are connected in series and are driven from the
Backup Control system.
4.4 Command Transfer
The term Command transfer is used to describe the procedure performed when the
control is transferred between manoeuvre stations without acceptance on either of the
stations. This is normally the procedure between wheelhouse (bridge) stations.
5 Location of Manufacturing Number
5.1 Marking Locations
Electrical cabinets and junction boxes are physically marked with a unique tag, and also
on all applicable drawings. The I/O cabinets are marked with the Rolls-Royce logotype
in the upper left corner.