Low speed is not
regulated by LOW
IDLE SPEED
potentiometer.
NOTE
On carbureted prime movers, the
minimum fuel stop rpm setting will
vary with prime mover
temperature. An improper cold
setting may interfere with the Low
Idle Speed Setting when the prime
mover is hot.
The Low Idle Speed setting may be below the minfuel position of the actuator or prime-mover fuel
stop. In this case, the output voltage to the actuator
will be zero (maximum for reverse acting controls).
The engine will be maintained at the min-fuel
position by the actuator or the prime mover min-fuel
stop. The conditions indicate that the min-fuel
position should be decreased by linkage
adjustment (diesel) or low-idle set screw (gas
engine), or the LOW IDLE SPEED setting should
be raised. If this does not correct the problem, the
2301A control may be faulty.
LOW IDLE SPEED potentiometer. If adjustment of the LOW IDLE SPEED
potentiometer causes erratic behavior, replace the
control.
Prime mover does
not decelerate when
Close for Rated
contact is open.
Faulty Close for Rated contact or
wiring.
The voltage from terminal 5 (–) to 2 (+) on low
voltage controls or 5 (–) to 6 (+) on high voltage
controls must be less than 2 volts. Replace the
contact or wiring as necessary.
LOW IDLE SPEED set fully cw
(be careful not to overtorque
the pot).
Turn LOW IDLE SPEED setting ccw with terminal 5
open.
2301A ramp circuitry.
WARNING
The speed-setting controls
have sufficient range to
override the ramp and bring the
prime-mover speed up to rated
while still in the low-idle mode
(because of control or
switching defect). A Close for
Rated contact that is
intermittent may cause the
prime mover to overspeed if the
RATED SPEED setting is
adjusted for rated speed with
terminal 5 open.
A faulty Close for Rated contact may remain in the
accelerate position with the contact open.
If the Close for Rated contact is operative, loss of
idle control may be due to a faulty circuit.
In general, adjustment of LOW IDLE SPEED will
vary the speed of the prime mover with the Close
for Rated contact in the decelerate (open) position.
Adjustment of LOW IDLE SPEED should not affect
prime mover speed when the Close of Rated
contact is closed.
Prime mover will not
stabilize at rated noload speed. The
instability may occur
at no load or it may
vary with load.
Control may be
erratic.
2301A Speed Control. Adjust GAIN, RESET, and ACTUATOR
COMPENSATION as described in "Adjust for
Stable Operation" and "Dynamic Adjustment" in
Chapter 3.
Speed setting controls. If adjustment of external speed trim causes
instability, check potentiometer with ohmmeter for
erratic behavior. (Turn power off). Use nonlubricating electrical cleaner if necessary. If internal
potentiometer is faulty, replace control.
Improper linkage adjustment. Make sure the actuator moves about 2/3 of its
travel from no load to full load. Be sure linkage
provides a proportional change in power for every
change in actuator terminal-shaft position. Refer to
the actuator manual for more detailed linkage
instructions.
Necessary wires not properly
shielded.
Electrical noise, caused by wiring carrying an ac
voltage or stray magnetic fields, can be picked up
by improperly shielded wire.
Noise will cause instability. See "Shielding" in
Chapter 3.
