KEY to figure 2-17:
1. Terminal board OITB
3. TB. wire through cover and screws.
Section IV. OPERATING UNDER USUAL CONDITIONS
(4) The switch escutcheon should now read
closed. The primary side of the transformer is now
a. The instructions in this section are published for
the information and guidance of personnel responsible
(5) Disengage handle, replace bar over
for the operation of the substation.
operating handle socket and lock. Return operating
b. The operator must know how to perform every
handle to storage cabinet.
operation of which the mobile substation is capable.
d. Close Main Breaker (fig. 2-11).
This section gives instructions to put the transformer on
the line from its primary source and (engage the low
counterclockwise through approximately 120 degrees.
voltage distribution feeder lines. Since nearly every
Then clockwise back through 120 degrees to the normal
installation will have different problems and
handle position. Four such complete movements of
requirements, the operator may have to vary a given
the handle are required to close the breaker. During the
procedure to fit that individual situation.
four counterclockwise movements and the first three
clockwise movements of the handle, the springs are
2-11. Energizing Transformer and Distribution Line
charged. After approximately 70 degrees travel of the
fourth clockwise handle movement the spring charged
a. Before Operation. Perform the before operation
mechanism is driven over-center and the breaker
preventive maintenance services (Table : 3-1 )1.
b. Safety Precaution. Perform the safety
precautions as indicated by the applicable NOTES,
(2) The charge-indicator numbered I to 4
CAUTIONS AND WARNINGS throughout the text.
moves with each complete handle movement.
(1) Make sure trailer is grounded and all
Indicating the number
of complete handle
ground connections are tight. A poor ground may be
movements that have been performed.
worse than none at all as it gives a sense of false
security to those working around the equipment and
(3) The indicator should now read closed.
may result in serious injury or damage to the equipment.
(2) Make sure all panels and covers are
e. Close Feeder Breaker (fig. 2-15).
replaced so that no live connections are exposed.
(1) Before closing a feeder breaker, it may be
(3) Check all circuit breakers to see that they
desirable to make sure there are no
are open, and have been racked to the connected
potential loads on the line to cause a
position. See paragraph 3-15 j.
surge and possible breaker tripping.
(4) Insure all compartment door panels are
closed and secured.
(2) The three feeder breakers are closed in
(5) Make sure all tools and equipment used
the same manner as the main breaker.
for installation have been stowed in their proper places
2-12. operating Substation
and that nothing has been left on the deck of the trailer.
a. Low Voltage Cabinet. The operator must make
c Close Load Break Switch (fig. 2-1 and 2-5).
periodic readings of the voltage and current using the
The (closing operation is spring charged.
voltage changes or excessive current loads require
mechanism Is manually charged but is completely
corrective action. The corrective action should be
disengaged from the operating handle. In this way,
correlated with organizational maintenance.
actual operation of the switch is independent of the
readings should be recorded.
(1) With key, unlock padlock and remove bar
covering operating handle socket of switch.
(2) From storage cabinet, take operating
(1) Maximum allowable voltage drop on a primary line
handle and insert into socket and engage operating
not employing a line regulator is 5 per cent.
(3) Rotate handle in a counterclockwise
direction as far as possible (approximately 1800) using a
positive motion throughout the entire stroke.