203Section 10 Governor AdjustmentsTP-6356 4/12
Note: Use 24 for three- or four-cylinder engines
and 16 for six- or eight-cylinder engines.
13. Idle Hold Time. Use the default value.
The Idle Hold Time specifies how long after
starting the engine stays at Idle Speed before
finishing the ramp to the target speed. The time
value has a resolution of one-tenth of a second.
During the startup sequence, the governor
increases the engine speed from the engine’s
crank speed to the active target speed at the
Startup Rate specified. When the Idle Hold Time
is nonzero, the initial target speed will be the Idle
Speed. After the Idle Hold Time times out, the
governor uses the Startup Rate to ramp the
engine to the selected Set Speed (A or B). The
startup sequence is complete after the engine
speed reaches the specified set speed.
14. Accel Rate. Use the default value.
This value specifies how fast the governor should
increase the engine’s speed when a new higher
speed is made active.
15. Decel Rate. Use the default value.
This value specifies how fast the governor should
decrease the engine’s speed when a new higher
speed is made active.
16. Startup Rate. Enter the value from the Governor
Parameter Summary.
This value achieves a smooth controlled engine
start. On diesel engines, this value minimizes
exhaust smoke at startup. When used in
conjunction with the Idle Speed and Idle Hold
Time, a brief warmup cycle can be programmed.
The Startup Rate specifies how fast the governor
should increase the engine speed when the
engine is started. The governor increases the
engine speed from the engine’s crank speed to the
active target speed at the rate specified. The
governor brings the engine to the Idle Speed for
the Idle Hold Time, then continues increasing the
engine speed at this same ramp rate until the
engine reaches the selected target speed (Set
Speed A or B).
Note: In cases where the target speed is less
than the Idle Speed and the Idle Hold Time
is nonzero, the startup ramp sequence
ends when Idle Speed is reached. Decel
Rate is then used to ramp engine speed
down to target speed from Idle Speed.
The ramp up pauses at the Startup Speed until the
governor senses an magnetic pickup (MPU)
signal greater than the Startup Speed. This
prevents the startup ramp from reaching
completion before the engine has started.
The governor treats MPU frequencies below the
Startup Speed as an indication that the engine is
cranking but has not yet started. The governor
treats MPU frequencies above the Startup Speed
as an indication that the engine has started and
the governor increases the engine speed until the
selected set speed is reached.
Note: In cases where target speed is less than
Startup Speed, the startup ramp sequence
ends when the target speed is reached.
During the startup sequence, the governor
increases the engine speed from the engine’s
crank speed to the active target speed at the
Startup Rate specified. When the Idle Hold Time
is nonzero, the initial target speed is the Idle
Speed. After the Idle Hold Time times out, the
governor uses the Startup Rate to ramp the
engine to the selected set speed (Set Speed A or
B). The startup sequence is complete after the
engine speed reaches the selected set speed.
17. Startup Limit (load share model only). Use the
default value.
The Startup Limit parameter limits the fuel
supplied to the engine during startup. This value is
useful in reducing smoke when starting diesel
engines.
Note: The engine may not start if the value is set
too low.
18. Torque Limit (load share model only). Use the
default value.
The Torque Limit parameter limits the fuel
supplied to the engine during heavy generator set
loads or generator set overloads.
Note: The engine may not be able to carry its
rated load if the value is set too low.
19. Integral Low Limit. Use the default value.
The Integral Low Limit value reduces underspeed
duration after a long or sustained overspeed
condition was present. The low limit helps reduce
the duration and amount of engine underspeed by
maintaining a minimum actuator position.
Note: Setting an improper value can prevent the
governor from reaching target speed.
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