Figure 2-7. Unit pole fully open

fig. 2-3) should be adjusted in a similar manner to the

adjustment of the upper stop. Move shims and washers

from the top to the bottom of the stop (or the reverse) as

required. Adjust the stops at both ends of the main shaft

the same amount to keep them balanced.

Arc chute mounting bolts

Arc chute

Upper terminal

Stationary primary contact finger

Shims

Primary blade stop

Primary contacts

Primary blade

Contact bolts

Arcing contact fingers

Figure 2-7. Unit pole fully open.

Contact bolt

Movable arcing contact fingers

(4) Primary and arcing contact alignment.

Tube spacer

Close the primary blades 112, fig. 2-81 slowly using tile

10.

Guide block

maintenance handle.

Note the engagement of the

11.

Buffer block bolts

primary contacts (4), arcing contact fingers 1 (and 8), and

12.

Primary contact blades

the guide block ( 10). The blades should center around

the guide block without hearing heavily on either side.

Figure 2-8. Contact arrangement.

They should also be centered in the primary and arcing

contact fingers. If the blades press hard against the sides

(5) Arc chute alignment. The arc chute must

of the guide block, loosen the two bolts (II) holding the

be positioned to allow entry of the auxiliary blade to latch,

block. Again check the contact alignment. If the contacts

are properly aligned, reposition the guide block and

and finally to release the auxiliary blade at the proper

time. Slowly close the contact arm and check the entry of

tighten the bolt. If the contacts are not in alignment,

the auxiliary blade (7, fig. 2-5) into the arc chute. The

loosen the bolts holding the top insulator and position the

blade should enter smoothly and be in the center of the

insulator to center the contacts. After securing the

opening. If the blade scrapes heavily on the sides of the

insulators, reposition the guide blocks and tighten the

bolts. Be certain the insulator is moved only in a

chute, loosen the

horizontal direction. Vertical displacement may cause

misalignment of the auxiliary blade contacts.

2-7