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21
IB-65020A
Equipment Description
3) MOC (Mechanism Operated Cell Switch)
Actuator
The mechanism operated cell switch
(MOC), located in the switchgear, is an
auxiliary switch operated by a lever which
extends from the circuit breaker operating
mechanism. Movement of the MOC
actuator (Figure 1, j) is directly related
to the movement of the circuit breaker
mechanism and contacts.
4) TOC (Truck Operated Cell Switch) Actuator
The truck operated cell switch (TOC),
located in the switchgear, is operated by
the circuit breaker truck position.
To accomplish this, a TOC actuator
(Figure 1, k) is located on the middle, left
side of the circuit breaker frame and it is
designed to strike the TOC as the circuit
breaker travels to the connected position.
5) Ground Connection
The ground connection (Figure 5) is an
assembly of spring loaded fingers that
grounds the circuit breaker frame as it
is inserted into the compartment. The
ground connection is located on the
bottom side of the frame between the
B and C phases. An extension of the
metal-clad switchgear ground bus
(Figure 3, h) is secured to the circuit breaker
compartment floor and engages the
ground connection as the circuit breaker
is placed into the disconnected position.
The ground connection system remains
engaged in all subsequent positions of the
circuit breaker until the circuit breaker is
removed from the compartment.
6) Shutter Operator
The shutter operator (Figure 2, h) is located
on each side of the circuit breaker frame.
As the circuit breaker travels between the
test/disconnected and connected positions
the shutter operator interacts with the
shutter lift arm (Figure 3, f ), opening and
closing the compartment shutters, allowing
the primary disconnecting devices to
connect or disconnect.
7) Test Position Interlock
The circuit breaker is equipped with an
test position interlock (Figure 1, r) which
prevents inadvertent removal of the
circuit breaker from the compartment by
engaging a block in the compartment.
e. v
AcuuM
I
nterrupterS
For a listing of the vacuum interrupters used
in Type CDR circuit breakers, see
Table E,
Primary Current Path
. A label which shows
the part number is attached to each vacuum
interrupter. Replacement vacuum interrupters
must have the same part number as the
original vacuum interrupter.
f. v
AcuuM
I
nterrupter
c
onnectIonS
The top stem of the vacuum interrupter utilizes
a pad that is bolted to the upper primary
assembly (Figure 27, #18). The lower vacuum
interrupter stem has a copper block threaded
onto it and is the movable end of the assembly
(Figure 27, #10). Fastened to the copper block
is a flexible copper shunt (Figure 27, #6) that is
attached to a stationary lower bus connector
(Figure 27, #2). An electrostatic shield which
covers the shunt and another primary
disconnecting device is attached to the lower
bus connector.
