5.2.2 Close-Open Stop Adjustment
Remove the handle mechanism cover by removing the
bolts securing the cover to the switch frame. Remove
the casting with the switch position indicators by
loosening 2 bolts. The adjusting bolts are now
accessible as shown in Fig 9. Adjustment is made by
loosening the lock nut and turning the bolt.
The bottom stop bolt adjusts the closed position. When
properly closed, the shaft rod ends should be slightly
over-toggle. Verify the adjustment by laying a straight
edge on top of the drive rod so that its end extends over
the shaft (see Fig. 3). If a 1/16" to 1/8" gap appears
between straight edge and drive rod, adjustment is
correct.
Page 8
Fig. 9
Close-Open Stop Adjustment Bolts
Check to see that the blades are closing fully. To do
this, measure the distance from the upper switch
terminal pad to the outer edge of the main blade (See
Fig. 10). This dimension should be 3-5/16" to 3-7/16".
Should adjustment be required, loosen the bolt holding
the drive rod to the main shaft clevis and adjust the
blade travel. Re-tighten the bolt to 25 foot pounds.
Fig. 10
Proper Main Blade Engagement
In the open position, clearance between the edge of the
main blade and the break jaw should be 6-5/8” as
described in Section 3 and Figure 2. The top stop bolt
adjusts this dimension (see Fig. 9).
If the switch is equipped with key interlocking, care must
be taken when replacing the switch mechanism cover to
ensure that it is properly repositioned. The key interlock
bolt must clear the open-closed indicating cam handle
casting when retracted.
5.2.3
Main Blade Alignment
It is important that the main blades be properly aligned
with the upper break jaw to insure smooth operation of
the switch. To align the blades and jaw after one or
both have been replaced, follow the procedure below:
Loosen the four hinge bolts and the two break jaw bolts.
Insert the removable handle in the maintenance hub on
the shaft and close the switch. (For safety purposes, the
switch will not fully close and will revert to the open
position if pressure on the handle is released). Hold the
switch in the closed position with the handle and tighten
the bolts on both the hinge and jaw to 25 foot-pounds.
Hold handle firmly throughout alignment process.
Upper
Stop Bolt
5.2.4 Arc Chute Alignment
Lower
Stop Bolt
Loosen the two arc chute mounting bolts. Adjust the
arc chute so that its opening is parallel to the main
blade. Tighten the mounting bolts enough to prevent
movement. Using the maintenance hub located on the
switch shaft (see fig. 7), slowly close the switch and
check that the flicker blade is in line with the arc chute
opening. If necessary, move the arc chute left or right
until it lines up with the flicker blade. Completely tighten
the arc chute mounting bolts and recheck the
alignment.
5.2.5 Vertical Position of Break Jaw
Close the switch. Check that the upper spacers of the
main blades are between 1/8”and 7/32” above the tops
of the break jaws. If they are not, loosen the bolts
holding the break jaw. Adjust as necessary. When
setting is correct, tighten bolts to 25 foot-pounds (see
Fig. 4).
3-5/16”
to
3-7/16”
5.2.6
Break Jaw Bolt and Hinge Contact Bolt
Tightness
The disk springs on the main blade assembly must
provide the necessary contact pressure between the
main blades and stationary mating parts when the
switch is closed (see Fig. 4). At the break jaw end, if
the elastic stop nut must be removed a sensitive torque
wrench used to set the proper contact pressure as
tabulated below.
Fault-Close Rating, kA Inch-pounds of torque
