S260-20-9
9
Figure 19.
Initial adjustment.
Figure 18.
Contact rod removal.
Figure 17.
Contact rod linkage.
3. Inspect the contact support housing
and contact rod for damage. If
replacement is not required proceed
to step 5. If replacement is required,
proceed as follows:
A. Disconnect the contact rod from
the operating link by removing the
C-ring and link pin. (Figure 17)
B. Remove the outer hex nut, lock-
washer and flat washer from the
bushing rod and lift contact housing
off the bushing rods.
C. To remove the contact rod from the
housing drive out the roll pin and
pull off the movable contacts
anchor block. (Figure 18)
D. Replace the damaged assemblies
and reassemble the contact rod
to the housing.
4. Reinstall the contact support housing
and contact rod.
A. Set the contact housing assembly
on the bushing rods. See Figure
2 to determine the proper orien-
tation of the damping resistors on
each phase of the Type VCR
switch.
B. VisualIy check that the contact
housing suppor t brackets are
approximately centered on the
bushing rods.
C. Reassemble the flat washers,
lockwashers and outer hex nuts
to both bushing rods. Check that
a flat washer is assembled above
and below each contact support
bracket. Jam nuts should be
snugged down but not tightened
completely until after contact
alignment has been completed.
D. Reconnect the contact rod to the
operating link with the link pin;
secure the pin with a C-ring.
E. With the switch mechanism in the
open position, the top edge of
the dashpot piston on the con-
tact rod should be approximately
1/32 inch above the top surface
of the dashpot. (See Figure 19.)
Adjust the nuts on the bushing
rods to move the contact hous-
ing up or down as required.
5. Reassemble the stationary contact
assembly using new contacts.
A. Type VR switch
( 1 ) Attach the block of the new
stationary contact assembly
to the support housing with
the hardware removed in
step 2A(1).
B. Type VCR switch
(1) Attach the load-carrying con-
tact assembly to the support
housing with the studs and
internal tooth lockwashers
removed in step 2B(4).
(2) Reassemble the insulator,
arcing contact assembly and
spacer onto the studs and
secure with the attaching
hardware removed in step
2B(2).
(3) Reconnect the resistor to the
bracket.
6. Install a new moving contact assem-
bly to the anchor block of the bush-
ing rod and secure with the screws
and stop nuts removed in step 1.
7. Align the contact assemblies.
A. Using a combination square
placed across the machined
edges of the head casting,
square the edge of the contact
housing with the head casting as
shown in Figure 20. obtain prop-
er alignment by adjusting the
inner hex nut.
NOTE: The “sailboat” alignment fix-
ture described on page 40 can be
used to square VR and VCR contact
structures.
