In this section you should learn how to operate the digital governor system
the functional layout of the dgu panel is shown below the grouping of functions
are the same as for the regulator part left and actuator part right move the
cursor over the elements in the indicator panel for a description of
their function normal regulating mode with real process input and output data
from engine selection of this mode is done automatically when command handle
is moved out of stop simulations of rpm command and scavenge air pressure is
possible when change lock is in open position
also if pension is running simulation of measured rpm is not possible in this
mode idle mode is automatically selected when rpm command handle is in stop
position all data is still monitored the mode makes it now possible to change to
test calibrate and self-test this is done by selecting parameter 1 mode
select and adjusting the data value to different values alarm indication system
in test will light and alarm is given to the alarm central direct fuel control
node regardless of measured rpm this mode is selected when the push-button
fuel setpoint is pushed and the change lock is pushed and the change lock is in
open position use caution if this is done while the engine is running this
mode is a bypass function of the regulator and is normally only used to
test the actuator performance test mode is only selectable if command handle is
in stop system may be set up with all input data simulated instead of real
sensors system may be set up with special calibration signals or routines
calibrate will also be lit up if the cow button is activated self testing of
computer memory is activated by pushing lamp test this will respond with reg up
if memory is OK or with error if there are any memory problems system in
running status regulation of fuel index on engine starting phase is activated
fixed fuel in start position system in engine stop condition rpm command set
point is zero rpm command setting is restricted by a limiting condition such
as manual limit setting or a critical speed range flashing regulating fuel
output is restricted by automatic limiting causes such as manual limit
setting speed limiting will scavenge air limiting engine is not allowed to have
more fuel other will indirectly reflect a status that can be pinpointed by
selecting appropriate parameter number for display parameter nine indicates to
low voltage in one of four power systems plus five volts plus 15 volts minus 15
volts plus twenty four volts detailed information is given by LED
indicator on adapter card rpm detector pickup system hardware failure detailed
information is given by LED indicator on adapter cards and on parameter 16 analog
input signal failure on rpm command handle in control room rpm command
handle on bridge or scavenge on engine communication failure between regulator
card and actuator card indicates that system is in test or calibration mode
other will indirectly reflect old alarms that has disappeared but is not reset by
parameter 16 or 17 these two parameters will indicate which alarms were
activated parameter 10 will indicate old ow if selected other alarm will not give
alarm - alarm central since the failure is no longer there in the parameter area
a set of relevant parameters together with their identification numbers are
listed after selecting a number by using the up/down buttons in the parameter
area the value will appear on the data display some data is readable like rpm
command measured rpm scavenge air pressure and some data is adjustable
like RPM limiter level fuel limiter level deadband the data value can be
adjusted if the selected parameter is adjustable this is achieved by pressing
the up or down button in the data value section the adjusted value
we'll take effect immediately adjustments are protected by the change
lock and the service code some parameters and some push buttons may be
changed pushed only when the commissioning key is installed and
turned to the open position most critical parameters have additional
safety locking by a service code that must be set this service code is a
special parameter that has to be set to a special value the complete set of
parameters is provided in the commissioning lists before powering off
the 24 Volt adjusted data can be saved by pressing the Save button when the
change lock is in open position if save is not pressed after an adjustment the
old adjustments will appear next time the power supply has been off and then
on again how to change regulating function in running conditions each
button has its own on-off LED indicator the indicator signal is fed back to the
panel from the computer in response to button operation
note that deadband and rough C buttons may be selected with no restriction the
fuel setpoint button may be operated only when the key lock is unlocked and
the function parameter is enabled click the buttons to get a description of
their functions in their own state and in the off state constant fuel button on
if the LED on the push button is lit then deadband is real that is flat the
dead band mode function reduces the motions of the governor when engine
speed is within the deadband limits there is no movement to fuel rec this
function will cause more variations and also a possible constant deviation on
the engine speed the dead band value is adjustable on parameter number 8 and is
usually set to 2 rpm for normal running at C this value can be increased for a
more stable actuator however special plant consideration may
limit practical use of this function if there is a shaft generator or similar
equipment constant fuel button off if the LED is
not activated the regulatable work with a reduced gain in the dead band zone the
reduction is adjustable and called reduction gain reduction factor of five
means that the activity of actuator is reduced by five times a dead band value
of two means plus minus two rpm ruff C button on if the LED on the rough C
button is activated the regulator selects the rough see gain setting for P
I governor refer to parameter list in addition the regulator can connect a
derivative function making the governor a PID regulator the d function is
selected on parameter 73 d gain on/off these alternate values may be programmed
to adapt more to a special seagoing condition such as a ballasted vessel or
rough sea situations rough C button off if the LED on the rough C button is not
activated the regulator selects the normal P eye governor settings fuel
setpoint button on this function is under the change lock so using the key
is necessary to activate this function transfer the system mode unconditionally
to normal and set point in setpoint mode the fuel index is directly set by the
commanding rpm handle setting the rpm command handle to dead slow will give 0%
fuel and full will give 100% fuel independent of the engine speed the
scaling of this function can be done that fuel setpoint parameters the fuel
limiters will still work so that the engine will not be overloaded with fuel
but it may easily be over speed see also fuel setpoint mode
fuel setpoint button off this function is under the change lock so using the
key is necessary to activate this function regulator is in normal
regulating mode the test buttons may be used in all system modes pressing one of
the upper buttons makes it possible to input a data value directly from the
panel the simulated input will initially equal that of the transducer it can then
be increased or decreased with the plus or minus buttons respectively to direct
the adjustment to only one of the signals given the relevant button has to
be pressed for a short time when the button lamp starts flashing the
adjustment of the selected data is possible a long press of the button
resets the data to the original source the adjustments are visual by selecting
the appropriate parameter number the rate button allows the adjustment to be
slow or fast note that the cowl button may be used in
normal running mode to add an artificial square wave noise in the RPM measurement
this is so as to be able to observe the regulating action of the governor move
the cursor over the indicator lamps to get their function description in the
parameter area a set of relevant parameters together with their
identification numbers are listed after selecting a number by using the up/down
buttons in the parameter area a value will appear on the data display some
data is readable like rpm command measured rpm scavenge air pressure and
some data is adjustable like RPM limiter level fuel limiter level deadband
the data value can be adjusted if the selected parameter is adjustable this is
achieved by pressing the up or down button in the data value section the
adjusted value will take effect immediately
adjustments are protected by the change lock and the service code most critical
parameters have additional safety locking by a service code that must be
set this service code is a special parameter that has to be set to a
special value a complete set of parameters is provided in the
commissioning lists before powering off the 24 volt adjusted
data can be saved by pressing the Save button
when the change lock is in open position if save is not pressed after an
adjustment the old adjustments will appear next time the power supply has
been off and then on again the servo on button activates and deactivates the
servo in calibrate and local Cal modes the set button enables a step change
test stimulant as commanding input to the actuator the on button must also be
set in order to make the actuator start in calibrate mode the auto button will
initiate an automatic calibration sequence of the actuator in local Cal
mode the auto button initiates an auto zero sequence on the actuator in idle /
manual control conditions the plus and minus buttons may be used for direct
up-and-down positioning of the actuator click on the buttons to get their
functional description