S&C Mark VI, Instruction Sheet

Page: 26 / 28

26
S&C Instruction Sheet 712-501
Inspecting the CS-1A
Switch Operator Motor Brake
Should the user wish to perform elective exer cising of the
complete Circuit-Switcher instal lation—the Mark VI Type
CS-1A Switch Operator may be conveniently decoupled
from the Circuit-Switcher, permitting elective exercising
of the operator at any time without requiring an outage
or switching to an alterna tive source . When the switch
operator is in the decoupled position the interrupters are
ren dered inoperative, permitting checkout of the system
protective scheme .
As indicated in S&C Data Bulletin 712-90, the brake
in the Type CS-1A Switch Operator should be inspected
every 2500 operations, or every 5 years, whichever occurs
more often .
Step 24
The inspection procedure is as follows, see Figure 30 on
page 26 .
a . Place the selector handle in the decoupled position .
b . Remove the two-pole pull-out fuseholders for the motor
and space heater .
c . Disconnect the linkage rod by removing the
Z\v
-20
3
1
Z\v
hex-head screw, lockwasher, flat washer, and spacer-
bushing from the end of the brake lever, as shown in
Detail A . Be careful not to lose these parts . Then raise
the brake lever and measure the vertical free play, as
shown in Detail B . This dimen sion should be
B\,
to
C\v
of
an inch . Should the measurement be outside this range,
brake-wear compensation is required; pro ceed to Step
d . If the measurement is within the range, reattach the
linkage rod and tighten the
Z\v
-20
3
1
Z\v
hex-head screw
securely, proceed to “i” below .
d . If the measurement is out of range, remove the four
B\zn
–
18
3
1
Z\v
screws used to attach the motor, withdraw the
motor, and care fully rest its shaft on the floor of the
enclo sure . Be careful not to lose the square key or tubu-
lar spacer (if furnished), which may remain on the
motor shaft .
Note: 115-volt ac motors utilize a
Z\v
-20 socket-head
set screw on the side of the brake disc hub, as shown in
Detail C . Loosen this setscrew approximately one-half
turn, using a
Z\,
Allen wrench, before removing the
motor .
e . Using a
C\cx
Allen wrench, loosen the pad assembly
socket-head set screw on the side of the caliper assem-
bly approximately one-half turn . See Detail A .
f . Then, using a
B\zn
Allen wrench, rotate the pad assembly
clockwise until the free play at the end of the brake
lever is
B\,
to
C\v
of an inch, as shown in Detail B . Now
tighten the
C\cx
-inch pad assembly socket-head set screw .
g . Insert the spacer-bushing through the angle bracket and
brake lever, and reattach the linkage rod using the
Z\v
-20
3
1
Z\v
hex-head screw, lockwasher, and flat washer .
Tighten the screw securely .
h . Insert the square key in the keyway, as shown in
Detail A . Slip the tubular spacer (if furnished) over the
motor shaft and rein stall the motor . Position the motor
such that the two weep holes on the side of the housing
face downward . Replace the four
B\zn
–18
3
1
Z\v
screws
used to attach the motor and tighten them securely . On
115-volt ac motors, further, retighten the
Z\v
-20 socket-
head set screw on the side of the brake disc hub .
i . Check the operation of the brake linkage as follows:
Pull the latch knob on the hub of the manual operating
handle and slowly pivot the handle forward from its
storage position toward its cranking position until the
brake disc can be rotated by hand . Be careful not to get
grease on the brake disc . Now measure the distance that
the end of the brake lever travels from the point of ini tial
brake release to the bottom of its stroke (which occurs
when the handle locks into the cranking position) . This
dimension should be
Z\,
to
Z\v
of an inch . See Detail D .
Should the measurement be out side this range, refer to
the nearest S&C Sales Office .
j . Finally, to check the functioning of the brake, decouple
the operator and then open and close the operator elec-
trically . After each operation, check the position of the
indicator on the appropriate travel-limit disc: it should
stop between numbers 2 and 8 . Should the indicator on
the travel-limit disc stop outside this range, refer to the
nearest S&C Sales Office .
Guidelines for Interrupter
Resistance Values
Mark VI Circuit-Switcher interrupters should have resis-
tance values under 200 micro-ohms for a new unit, and
under 500 micro-ohms for a unit that has been in service . If
a Mark VI interrupter is outside these values, contact your
nearest S&C Sales Office .
Inspection Recommendations