Woodward 723PLUS Original Instructions Manual Download

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723PLUS/Single Engine Marine Propulsion

Manual 02880

Woodward

If remote operation is selected after the engine reaches rated speed, the control
will ramp speed to the reference value set by the Remote Speed Setting milliamp
input based on the raise or lower rate. The Remote Speed Setting operates from
4 to 20 mA (1 to 5 Vdc). The values of the 4 mA and 20 mA remote reference set
points must be set between the raise and lower limit set points. The 4 mA
Remote Reference set point may be set to a lower or higher speed than the 20
mA set point, providing for either direct or reverse-acting remote speed setting.

If a remote input is present and selected when the Rated Speed contact is closed
or during the idle to rated ramp, the speed reference will ramp to the speed
reference value determined by the milliamps on the Remote Speed Setting input,
based on the raise rate set point. This may not be the desired mode of operation,
so be sure to understand the implications of operating the control in this manner.

Below 2 mA (0.5 Vdc), the remote input is considered failed. Between 4 and 20
mA (1 and 5 Vdc), the control determines the required speed reference based on
a straight line between the 4 mA Remote Reference and 20 mA Remote
Reference set points. If a difference is detected between the current speed
reference and the remote reference computed from the mA input, the current
speed reference is raised or lowered at the rate determined by the raise or lower
rate to bring the speed reference into agreement with the remote speed
reference. The remote reference will not increase speed over the raise limit or
lower it below the lower limit.

When in remote mode (Raise and Lower Speed contacts both closed), if the
remote input goes below 2 mA (0.5 Vdc), the speed reference will ramp down to
the lower limit.

If the Rated Speed contact is opened for idle after operating at rated, the control
will immediately ramp engine speed to idle based on the decel time set point.

Dual Dynamics

The PID dynamically changes the fuel demand based on the difference between
the Spd Ref set point and engine speed. If engine speed is less than the Spd
Ref, the PID will cause the fuel demand to increase. If engine speed is greater
than the Spd Ref, the PID will cause the fuel demand to decrease.

The Dual Dynamics is two independent sets of dynamics which are used to
control how the PID changes the fuel demand. The 2nd Dynamics discrete input
determines which set of dynamics is used by the PID. The 1st Dynamics set is
used when the discrete input is FALSE (with the contacts open) and the 2nd
Dynamics is used for a TRUE discrete input. The two sets of dynamics are
provided for use where engine operating conditions dramatically change, such as
dual fuel applications.

Each set of dynamics can be varied automatically as a function of load. Refer to
Initial Adjustments in Chapter 4 for a further description of the dynamic
adjustments.