Removal of Circuit Breaker

(4) Reset racking handle to its lowered position

(6)

Bus connections, 3 phases, neutral and

and lift it again. This operation must be performed five

ground.

times to completely disengage the cams from their

CAUTION

racking pins.

When making bolted bus connections clean

(5) After the fifth lifting stroke let handle drop to

the silver plated contacting surfaces with a

its normal position.

clean cloth or solvent if required.

(6) Pull the breaker out of its compartment until it

Sandpaper or abrasives must not be used.

engages the test stop.

Apply contact lubricant. Bolt the bus

(7) Depress the test position stop handle (located

connection using a bolt, washer and

directly beneath and in middle of breaker), and pull the

lockwasher. Refer to table 1-1 for the proper

breaker out as far as the drawout tray will travel.

torque values of bus bolts and nuts.

b. Lifting Circuit Breaker from Drawout Tray.

(1) Use a portable crane (hoist) and a web sling

(7) Insert the two wires in the conduit (from high

approximately I inch wide and 6 feet long with a loop on

voltage section) through the conduit connection on lower

each end. Both sling and crane must be capable of lifting

right end wall of transition.

and supporting 400-500 lbs.

(8) Connect conduit to transition wall and secure

(2) Place sling under and across the two top

it to transformer (fig. 2-12).

frames of the breaker (fig. 2-16).

(9) Connect the two wires from the conduit to

(3) Loosen and remove the two 3/8 inch hex

the terminal board HX mounted on the lower left inside

head bolts in front, of the base angles of the breaker

wall, connect to terminals I and 2.

fastening breaker to drawout tray.

(I0) Replace transition rear access cover and

(4) Lift the breaker approximately I / 2 inch off

secure with its 24 bolts and washers.

the dowel pins in rear bottom of the drawout tray.

(11) Open both rear doors and check for

(5) Pull the breaker forward until its primary

alignment and that weatherproof seal has not been

contacts clear the cabinet.

disturbed.

(6) Push the tray all the way back into the

(12) Check that all bus connections are tight,

compartment.

fuses in place.

(7) Close the breaker compartment panel.

(13) Check both front doors as in paragraph (11)

(8) The breaker can now be moved to wherever

above.

the situation dictates.

(14) Check circuit breaker panels alignment and

working.

2-22.

Circuit Breaker Installation

(15) Check

circuit

breaker

drawout

mechanism for alignment and workability.

a. Clear Trailer deck of all unnecessary objects and

(16) Close and secure all panels and doors.

equipment from area where breaker is to be installed.

WARNING

b. See paragraph 2-21 b for lifting circuit breaker.

Whenever circuit breakers are being

c. Inserting circuit breaker.

installed,

removed,

inspected,

(1) Make sure that breaker contacts are open.

maintenance is being done, the breaker

(2) Raise or lower breaker to a position

must be open and the closing springs

approximately six inches above its compartment drawout

restrained by the safety pin. Otherwise

tray. (fig. 2-1 6).

serious bodily injury and / or damage to the

(3) Pull drawout tray out under the breaker until

equipment may result. See paragraph 5-3

the outer limit stop is reached.

for safety pin insertion.

WARNING

2-21. Removal of Circuit Breaker

Make sure a bolt is in each of the front

a. Breaker Withdrawal.

bottom mounting holes of the housing, the

(I) Push trip button, breaker should trip free and

bolt heads provide the limit stop for drawout

indicator read "OPEN".

This also releases positive

tray. If these are not in place, serious bodily

racking interlock.

injury or damage to equipment may result.

CAUTION

See Figure 2-16.

Never open breaker compartment panel

(4) Lower the breaker to a distance of about I / 2

unless the breaker is open.

inch above dowel pins on the tray. Push the breaker back

(2) Open breaker compartment hinged panel.

into its compartment so that the rear bottom angle of the

(3) Lift the racking handle as far as it will go.

breaker is against the guides. The guides are on the tray

This re-engages the trip interlock to hold the breaker trip-

directly back of the dowel pins.

free for the remainder of the withdrawal racking operation.

2-16