Index Locomotives - books DIESEL LOCOMOTIVE OPERATING NO. 2315 for MODELS F9, FP9, FL9 - manual 1997 year
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OPERATION
F9-2-657
NOTE: The most effective use of the dynamic brake is between 15 and
25 miles per hour depending on the gear ratio. Speed on grades
should not be allowed to "creep up" by careless handling of the
brake, as this is a holding brake and is not too effective in
slowing down heavy trains on steep grades.
These locomotives can be operated in dynamic braking coupled
to older units that a r e not equippedwith brake current limiting
regulators. If all the units are of the same gear ratio, the unit
having the lowest maximum brake current rating should be
placed as the lead unit in the consist. The engineman can then
operate and control the braking effort up to the limit of the unit
having the lowest brake current rating, without overloading the
dynamic brake system of a trailing unit. The locomotive consist
MUST always be operated so as not to exceed the braking
current of the unit having the lowest maximum brake current
rating.
Units equipped with dynamic brake
current limiting regulators and of
different gear ratios will require
special operating instructions when
used in multiple with an F9 type
locomotive in dynamic braking.
230
Dynamic
Brake
Selector
Switch
The dynamic brake unit
selector switch, Fig. 2-14, located at
the engineman's control station, has
four positions (1, 2, 3 and 4) and
shouldbe set to correspond with the
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OPERATION
number of units in the locomotive consist. This switch should be set
before leaving the terminal and must not be changed even if an engine is
isolated enroute. This switch is changed only if the number of units in
the locomotive consist is changed.
231 Dynamic Brake Warning Light
The
dynamic
brake
warning light on the engineman's instrument panel will flash on when an
excessive braking current is developed.
Generally, the over-current
is only temporary, and the dynamic brake current limiting regulator will
automatically reduce the braking current to a maximum 700 amperes.
232 Dynamic Brake Grid
Blower
The
braking
current,
generated
by
the
traction motors in dynamic
braking, flows through the
grids to be dissipated as heat.
The grids are cooled by a
motor driven fan, Fig. 2-15.
The grids and fan are located
in the top of the carbody above
the main generator and air
compressor. Power generated
by the No. 1 and No. 3 traction
motors drives the grid blower
motor.
233 Dynamic Brake Wheel Speed Control
The relays, used to correct
a wheel slip while under power, are also used to correct the tendency of
one pair of wheels to rotate slower while in dynamic braking due to an
unusual rail condition.
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OPERATION
F9-2-657
When a pair of wheels is detected tending to rotate at a slower
speed, the retarding effort of the traction motors in the unit affected is
reduced (main generator battery field excitation is reduced in the unit
affected) and sand is automatically applied to the rails ("Automatic
Sanding" switch on engineman's control panel must be "ON" position).
When the retarding effort of the traction motors in the unit is reduced,
the tendency of the wheel set to rotate at a slower speed is overcome.
After the wheel set resumes normal rotation, the retarding effort of the
traction motors returns (increases) t o its former value. Automatic
sanding continues for approximately 10 seconds after the wheel speed is
corrected.
234
Hump Speed Control
When used, the electrical hump
speed control circuit controls the positioning of the load regulator in
order to maintain constant locomotive speed regardless of the number of
cars in the train.
The hump speed controls are shown in Fig. 2-16.
To set the hump control circuit, Fig. 2-17, into operation, bring the
throttle out as far as possible, consistent with desired train speed and
Hump Speed Control
Fig. 2-16
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OPERATION
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OPERATION
F9-2-657
adequate cooling air to the traction motors.
Leave it in that position for
the remainder of the hump operation. Turn the hump control toggle
switch to its ON position and adjust the rheostat knob, Fig. 2-16, to give
the exact desired speed. Once the desired train speed is reached, there
should be no need to move the knob again. If an extremely long train is
to be handled, it may be necessary to trim the amount of battery field
excitation to reduce speed after a substantial number of cars have been
released. This can be accomplished by turning the hump control rheostat
slightly toward decrease until the desired train speed is regained.
As shown in Fig. 2-17, the hump control circuit is a bridge type,
between the two ends of the hump control rheostat on one side and the
load regulator and battery field on the other side.
The Diesel engine
governor pilot valve tries to force the load regulator toward maximum
field in an effort to load the engine by increasing main generator
excitation. This action continues until the potential at point 1 of the
hump control relay (HCR) is approximately 1/2 volt greater than at
point 3. The current flow then travels in the opposite direction through
the HCR causing the 8-2 contacts of the HCR to close which completes
a circuit to the ORS solenoid in the governor. The ORS acts upon the
pilot valve of the governor forcing the load regulator toward minimum
field until the potential across 1 and 3 causes the HCR to "drop out."As
the HCR drops out the 8-2 contacts open and another cycle begins.
In order that full load regulator effectiveness can be utilized, a
hump relay (HR) becomes energized when the hump control toggle
switch is turned to its ON position.
The
A-B
interlocks
of
HR
complete a circuit to the load regulator control relay (LRC). The E-F
interlocks of LRC in turn open to remove the resistance from around the
load regulator.
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F9-2-657
OPERATION
235 Motor Lockout Switches
Four
motor
lockout
switches
(CO1, C02, C03, and C04) are mounted on the reverser drum, Fig. 2-
18.Each switch permits the isolation of the corresponding traction motor
from the power circuit (CO1 cuts out traction motor No. 1) in the event
that a traction motor is grounded.
Always isolate the engine before
opening a motor lockout switch. Not more than one traction motor
should be cut out at any time, and the armature of the traction motor cut
out must be free to rotate.
Motor Lockout Switch
Fig. 2-18
236 Operating "B" Unit With Hostler's Controls Operation at the hostler
station is the same as an "A" unit. The switches are beside the
controller.
The brake valve cutout cock is below the brake valve.
The bell valve is a globe valve near the controller. Only No. 1 transition
is available.
Movement of the reverse lever automatically places the
locomotive in No. 1 transition. It should be remembered that the
operation of the "B" unit controls will operate all units joined to it.
When securing the hostler control, be sure all switches are open,
the controller and reverser pinned, and the brake valve cut out, as these
items can affect operation at any other station or cab.
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OPERATION
F9-2-657
237
Safety Control Foot Pedal
The safety control foot pedal (if
used) is located in front of the engineman's seat. On locomotives
equipped with a hinged automatic brake valve handle, the handle
provides an alternate control when it is depressed sufficiently to just
contact the sanding bail. Either the pedal or the automatic brake valve
handle must be kept depressed at all times except when the locomotive
is stopped and the locomotive brakes are applied (30 pounds or more
brake cylinder pressure).
If both the foot pedal and the automatic
brake valve are released at the same time, a penalty application of the
brakes will result.
238 Brake Pipe Flow Indicator
A brake pipe flow indicator is a
very useful supplement to locomotive air brake equipment. The
indicator provides the engineman with the following desirable
indications:
1. It indicates a train line that is sufficiently charged to start the
initial brake test when the differential between the pointer hand
and sector hand reaches 7 pounds or less.
2.
It indicates the continuous system leakage of the particular train
being handled. This indication is the lowest number reached
after the train is fully charged, the reading should be 5 or less.
3. A change in reading from the number indicated as a normal
continuous system leakage indicates one of the following
conditions:
a.
Conductor initiated Service Reduction from the caboose.
b. Conductor
initiated
Emergency
Application
from
the
caboose.
c. An application caused by a break-in-two or separation of the
train.
4. This indicator provides readings in lap position of the brake
valve from 50 to 110#, as well as differential indication in
running position of the brake valve. Therefore, it may be used
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OPERATION
conveniently when checking brake pipe leakage in lap position.
5. Only practice and experience will bring out all the uses of this
indicator. Some of the troubles which can be detected are faulty
feed valve operation, leaks in the rotary valve seat, and other
potential brake valve failures.
The flow indicator consists of a duplex gauge case and bezel with a
special movement, and employs bourdon tubes with enough sensitivity
to indicate differentials encountered during the various brake operating
conditions. This is accomplished by measurement of differential
pressures across the feed valve, which would indicate the degree of
work the feed valve was required to do in order to supply the demand of
the brake pipe.
Figs. 2-19 through 2-24 explain the use of the indicator by
illustrating the position assumed by the gauge under various conditions.
Partially Charged Train,
Uncharged Train Or
Or Reduction Made From
Dead Brake Pipe
Rear End Of Train
Fig. 2-19
Fig. 2-20
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