S&C Mark V Circuit-Switchers Installation Manual page 22

Installation
STEP 4� Become familiar with the parts of the blade mech-
anism as seen in Figure 17 on page 21. Check each
circuit-switcher pole-unit for adequate pene-
tration of the blade into the jaw contact during
completion of the closing stroke. See Figure 12 on
page 19. The blade should exert a slight pressure
against the blade bumper stop before the start
of the "wiping in" rotation. After the current-
carrying tongue contacts are completely rotated
into the jaw contacts, the blade pressure against
the bumper stop will tend to be relaxed, and a
1/8-inch (3.2-mm) maximum gap is permissible
between the blade and the blade bumper stop.
Should a blade-penetration adjustment be
required, proceed as follows:
(a) With the blade in a partially Open position,
loosen the rotating-yoke lock nut. See
Figure 18.
(b) Remove one of the cotter pins from the rotating-
yoke coupling pin. Then, remove the coupling
pin itself.
(c) Turn the rotating yoke in or out on its
threaded stud to decrease or increase blade
penetration. Half-turn adjustment incre-
ments are suggested between tryouts.
Remove yoke
pin
Figure 18� Blade penetration adjustment�
22 S&C Instruction Sheet 711-510
STEP 5�
Loosen
rotating-yoke
lock nut
(d) Replace the rotating-yoke coupling pin and,
if no further adjustment is required, also
replace the cotter pin.
(e) Before tightening the rotating-yoke lock nut,
observe the action of the ball joint during
opening and closing operations. Note that
the "window" of the ball-joint socket should
permit the socket to roll freely with the
motion of the blade without binding against
the ball-joint shaft.
Then, with the blade in the fully Closed
position and while holding the ball-joint
socket so the edge of its window nearest
the interrupter target is close to the ball-joint
shaft, tighten the rotating-yoke lock nut.
After each pole-unit has been checked and
adjusted as described above, return it to the
fully Open position. Then, remove the temporary
hand-operation adapter.
Turn
threaded
stud