S&C Mark VI Instructions For Installation Manual page 14

INSTALLATION
Step 14
Prepare the electrical connection to the
disconnect bus as follows:
a. Thoroughly clean the interrupter bus with
a soft cloth. Wire-brush the interrupter
casting.
b. Immediately apply a liberal coating of
Burndy Penetrox® A or other suitable alu-
minum connector compound to the clean
surfaces.
c. Apply a coating of Penetrox A to the threads
of two ¹⁄₂–13
1¹⁄₄ hex-head stainless-steel
cap screws.
d. Attach the disconnect bus to the set of
tapped holes in the disconnect casting,
using the coated cap screws and four ¹⁄₂-inch
stainless-steel Belleville washers. See Figure
14. Tighten the screws to a torque of 50 to
60 ft.-lbs.
Step 15
Attach the interrupter bus to the disconnect bus
using the four ¹⁄₂–13
1¹⁄₂ hex-head stainless-
steel cap screws, Belleville washers, and nuts
furnished. See Figure 15.
Avoid excess tension or torque between the
interrupter bus and the disconnect bus. If the
holes between the two sections of buswork
do not line up properly, loosen the hardware
securing the interrupter mounting brackets to
the disconnect base, and shift the interrupter
until the holes are aligned. Retighten the inter-
rupter hardware to a torque of 70 to 80 ft.-lbs
if necessary.
Step 16
Remove the lifting sling from the interrupter.
Ç
CAUTION
Never exceed the recommended torque
limit. The interrupter base contains SF
gas and is pressurized to 75 PSI. Damage
to the interrupter may occur if studs
are overtorqued.
712-502
¹⁄₂–13
1¹⁄₄ stainless-steel
cap screws and lockwashers
Disconnect bus
Interrupter bus
Figure 14. Attach the disconnect bus to the tapped holes in the disconnect
casting. Overlap the interrupter bus.
Figure 15. Attach the interrupter bus to the disconnect bus.
6
14
Four ¹⁄₂–13
1¹⁄₄ stainless-steel
cap screws, Belleville washers,
and nuts
Disconnect casting