Adjusting The Pole-Units - S&C Mark V Circuit-Switchers Installation Manual

Adjusting the Pole-Units

STEP 1� Make a final check of each circuit-switcher
pole-unit for adjustment and alignment of the
blade with the jaw-contact assembly. As each
circuit-switcher blade is closed, the fault-closing
tongue contact should engage each of the fault-
closing jaw contacts with equal pressure and the
current-carrying tongue contacts should enter
the current-carrying jaw contacts with equal
clearance on each side. The silver-surfaced
area of the current-carrying tongue contacts
should center laterally with the silver-surfaced
current-carrying jaw contacts, and the blade
should rotate with slight pressure against the
blade bumper stop and come to rest either on
the stop or slightly above it. See Figure 12.
If adjustment of the position of the jaw-contact
assembly is necessary to obtain the described
alignment, the insulator mounting-flange bolts
should be loosened and the insulator shifted as
required. It may also be necessary to adjust the
front-insulator-support leveling screws.
To maintain the correct effective height of
each individual insulator stack, it is impor-
tant that only three of the four leveling nuts
on any one insulator support be adjusted. One
leveling nut should always remain in its original
(factory-set) position to avoid changing the effec-
tive height of the insulator. See Figure 13 on
page 20.
STEP 2� With the hand-operation adapter, operate each
circuit-switcher pole-unit to its fully Open
position. The drive-shaft crank, as it goes into
toggle, should be felt to strike firmly against an
internal drive-shaft crank stop (not visible) in the
drive-shaft assembly. The toggle-loading snubber
(located on the pole-unit base adjacent to the
rotating-insulator support, see Figure 14 on page
20 ) should maintain positive-toggle locking. Both
the internal drive-shaft crank stops in the drive-
shaft assembly and the toggle-loading snubbers
have been carefully adjusted at the factory, and
readjustment should not be attempted.
Blade
Figure 12� Tongue-contact and jaw-contact assemblies
shown in partially Closed and fully Closed positions�
S&C Instruction Sheet 711-510
Installation
Current-carrying
tongue contacts
Current-carrying
jaw contacts
Blade bumper
stop
Fault-closing
jaw contacts
Fault-closing
tongue contacts
19