Woodward 2301D, Инструкция по установке и эксплуатации, Страница: 90 / 130

2301D/2301D-EC Digital Control Manual 26247
82 Woodward
The idle speed set point is provided for engine warm-up or cool-down cycles. Idle
speed may be set equal to or less than the rated speed set point. Idle is
independent of the lower limit set point and may be set at a lower speed. The idle
speed set point is selected when the Rated contact is open, if the start reference
is removed either by configuration or engine speed above start speed. Closing
the Rated contact ramps the speed set point from idle to rated, if the start
reference is removed.
Closing either the raise or lower contacts while ramping from idle to rated results
in immediate cancellation of the idle to rated ramp, and the ramp will stop at that
point. After acceleration to rated speed is completed, the raise and lower
commands increase and decrease engine speed based on the raise and lower
rate settings. The raise and lower commands will not increase the speed
reference above the raise limit or below the lower limit. The raise and lower
commands can be used as speed trim inputs for manual synchronization. Or if
the system uses droop operation for paralleling, the raise and lower inputs will be
load setting inputs.
If remote speed setting operation is configured and enabled after the engine
reaches rated speed, the control will ramp speed to the reference value set by
the Remote Reference input at the Remote Reference increase or decrease time
settings. The Remote Reference range is selectable and can be configured for
one of four operating ranges: from 4 to 20 mA, 0 to 20 mA, 1 to 5 V, or 0 to 5 V.
The minimum input value (4ma, 0mA, 0 V, or 1 V) Remote Reference set point
may be set to a lower or higher speed than the high input (20 mA or 5 V) set
point, providing for either direct or reverse-acting remote speed setting.
If the Remote Speed Reference input is configured and enabled when the
Idle/Rated contact is closed or during the idle to rated ramp, the speed reference
will ramp to the Remote Reference input value at the remote reference increase
or decrease rate settings. This may not be the desired mode of operation, so be
sure to understand the implications of operating the control in this manner.
If a difference is detected between the present speed reference and the remote
reference rpm value, the present speed reference is ramped up or down at the
increase or decrease rate until the present speed reference matches the remote
speed reference rpm value. The remote reference will not increase/decrease the
speed reference above the maximum input value or below the minimum input
value. (see Figure 6-3).
Figure 6-3. Remote Speed Reference