Figure 2-9. Unit pole opening

two arc chute mounting bolts ( 2) at the top and the chute

so the blade will travel the full length without binding or

heavy scraping, and tighten the bolts. A dimension of 1-

1/16 inch should be maintained from the rear edge of the

arc chute to the front edge of the primary finger contact

support at all times, when moving or re-aligning the chute.

See figure 2-5. The auxiliary blade arc chute contacts (2,

fig. 2-91 inside the chute should be properly positioned to

latch the auxiliary blade when this dimension is

maintained. The auxiliary blade must be released by the

contacts when the primary blade has been opened to a

predetermined gap. With the operating springs blocked,

open the primary contacts and slowly move the primary

blade until the auxiliary blade is released. At the point of

release, the gap from the lower edge of the primary finger

(the bottom finger 2, fig. 2-7) to the primary blade stop

13, fig. 2-7) should be 4-7 /8 to 5-3 / 8 inches. If the gap

is not correct the vertical location of the chute must be

changed. For gaps greater than the above range the

chute must be lowered. For gaps that are less the chute

must be raised. To adjust the chute, remove the upper

and lower mounting bolts (2 and 10, fig. 2-5). Move

1. Blade stop block

shims (3, fig. 2-81 from the bottom to the top of the

2. Arc chute contacts

support to decrease the gap. To increase the gap move

3. Auxiliary blade

some of the top shims to the bottom support. When the

4. Spacer

release gap is properly set, check again the dimension

5. Arc chute side

from the back edge of the chute to the primary contact

6. Primary contact blade

finger support as directed above.

7. Auxiliary blade spring

8. Camming screw

9. Lock nut

10. Auxiliary blade release hook

11 Operating rod

Figure 2-9. Unit pole opening.

2-8