Installation; Assembly Of Individual Pole-Units - S&C Mark V Circuit-Switchers Installation Manual

Installation

Assembly of Individual Pole-Units

STEP 1� Without removing the circuit-switcher pole-units
from their skids, arrange them in the position
and order in which they will be raised onto
the mounting pedestals or structure as shown
on the erection drawing. Each pole-unit base
is numbered, corresponding to its position as
indicated on the erection drawing. (The pole-unit
numbers are not necessarily phase designations.)
The three pole-units have the same serial number
located on the nameplate of each pole-unit base.
In the event more than three pole-units are avail-
able, care should be taken to be sure the serial
numbers are matched for each circuit-switcher
installation. The switch operator also has the
circuit-switcher serial number on its name-
plate so that operator is used with the correct
circuit-switcher.
Each skid should rest firmly and be reasonably
level. Shoring under the skids may be necessary
if the ground is uneven.
Repeat the following Steps 2 through 13 for
each of the three circuit-switcher pole-units.
Note: Steps 4 through 13 apply only to circuit-
switchers rated 69 kV and up, for which the
insulators are shipped separately. If the pole-
units are shipped assembled, skip to Step 14
on page 17.
STEP 2� Carefully remove the outer crate (if provided),
but leave the skid attached to the pole-unit base.
Inspect for any obvious shipping damage before
continuing installation.
STEP 3� Attach the temporary hand-operation adapter, to
the drive-shaft crank. See Figure 4 on page 11.
With the hand-operation adapter, open and
close the pole-unit several times to obtain the
"feel," and observe the operation of the circuit-
switcher as adjusted by the factory. Note the
following operational parameters:
(a) During the opening operation an initial
peaking of effort is required as the drive-
shaft crank leaves its closed, toggle position.
Rotation should progress smoothly but with
a noticeable increase in effort as the blade
passes beyond its half-open position. At this
position the stored-energy source within the
brain begins to charge as the interrupter
closes.
10 S&C Instruction Sheet 711-510
(b) As opening continues, the stored-energy
source charges and latches, and a final
peaking of effort again is required as the
drive-shaft crank goes into toggle against
the open stop. The blade will now be in the
fully Open position and the interrupter will
be in the Closed position, as indicated by
the gray interrupter target on the side of the
brain. See Figure 2 on page 8.
(c) During the opening sequence, the inter-
rupter target on the side of the brain housing
changes from gray to yellow when the inter-
rupter is opened, then back to gray, indicating
the normally Closed position of the inter-
rupter. In addition, the interrupter target
remains gray when the circuit-switcher is
closed, indicating the interrupter is in the
Closed position.
(d) As the circuit-switcher moves toward the
Closed position, the current-carrying
tongue contacts enter the current-carry-
ing jaw contacts with equal clearance on
each side. See the "Adjusting the Pole-Unit"
section on page 19 and Figure 12 on page 19.
For Circuit-Switchers rated 69 kV and up,
this same engagement should be attained
after the live parts have been removed and
reassembled on the insulator stacks.
(e) The blade crank-arm at the top of the brain
rests against the blade crank-arm stop in
the fully Open position. See Figure 16 on
page 21.
No more than a 1/32-inch (0.8-mm) gap
exists between the blade crank-arm and
its associated blade crank-arm stop in the
Closed position. See Figure 17 on page 21.
(f) As the circuit-switcher reaches either the
fully Open or fully Closed position, the
drive-shaft crank will be felt to strike firmly
against an internal drive-shaft crank stop
(not visible) in the drive-shaft assembly.
See Figure 4 on page 11. The toggle-load-
ing snubbers (located on the pole-unit base
adjacent to the rotating-insulator support
(See Figure 14 on page 20)) maintain positive-
toggle locking at each end of the operating
stroke. 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.