Winco DPG-2145-001 - Manual (Page 37)

Manual 36526F DPG-21XX-00X Digital Controllers
Woodward 29
Startup Sequence
The following example describes the DPG-21XX-00X startup sequence.
Engine cranking begins at point A. After a short time, the engine starts and at point B
the engine speed exceeds the STARTUP SPEED (the initial target speed) and the
controller now considers the engine to be running.
T
he controller’s startup sequence begins at point B by ramping the target speed up
from the STARTUP SPEED at the STARTUP RATE. In this example, the STARTUP
SPEED is set to 500 Hertz, the STARTUP RATE is set equal to 250 Hertz per second,
and the IDLE SPEED is set to 1500 Hertz. It will take 4 seconds for the target speed to
ramp up 1000 Hertz (IDLE SPEED minus STARTUP SPEED) and reach point C.
This example uses the IDLE HOLD TIME and has it set to 100 tenths of a second
so
the target speed will be held at the IDLE SPEED (1500 Hertz in this example) for 10
seconds. At point D, the IDLE HOLD TIME has elapsed and the target speed is ramped
up at the ACCEL RATE. In this example, the ACCEL RATE is set equal to 500 Hertz
per second.
The example also has SET SPEED A set at 3500 Hertz so it will take 4 seconds for the
target speed to ramp up 2000 Hertz from the IDLE SPEED. Ramping stops at point E
when the target speed reaches SET SPEED A. The startup sequence also ends at
point E assuming the engine speed has been tracking the target speed and has
reached SET SPEED A.
B
500
1000
1500
2000
2500
3000
3500
C D
5 10 15 20 25 30 35 40 0
0
Time in seconds
A E
Startup Sequence Example
STARTUP RATE = 250 Hz/sec
STARTUP SPEED = 500 Hz
IDLE SPEED = 1500 Hz
SET SPEED A = 3500 Hz
IDLE HOLD
TIME = 100
ACCEL RATE = 500 Hz/sec
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