Section IV. OPERATING UNDER USUAL CONDITIONS

KEY to figure 2-17:

1. Terminal board OITB

2. Heater

3. TB. wire through cover and screws.

Section IV. OPERATING UNDER USUAL CONDITIONS

(4) The switch escutcheon should now read

2-10. General

closed. The primary side of the transformer is now

a. The instructions in this section are published for

energized.

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

(1) Rotate

the

charging

handle

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.

closes.

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

NOTE

voltmeter, ammeter and their selector switches. Line

The (closing operation is spring charged.

The

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.

All

actual operation of the switch is independent of the

readings should be recorded.

operator.

(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.

mechanism.

(3) Rotate handle in a counterclockwise

direction as far as possible (approximately 1800) using a

positive motion throughout the entire stroke.

2-29