Description
Stationary and Moveable Drawout Elements
Simplified Minimum Depth Drawout Mechanism
The two elements of a drawout constructed SB Encased
Systems Breaker are referred to as the Stationary Draw
out Element and the Moveable Drawout Element. The sta
tionary drawout element mounts from the front or bottom
into a standard switchboard . Bottom mounting flanges
are provided for optional mounting arrangements. The
moveable drawout element mounts onto the stationary
drawout element's two extension rails. This allows the
moveable drawout element to be racked i nto and out of the
stationary drawout element. For inspection purposes, the
moveable drawout element must be removed from the
extension rails to a work area. Detailed outline drawings of
the stationary and moveable drawout elements are in the
Outli ne Dimensions section .
There are four positions of the moveable drawout ele
ment: 1 .) connected,
2.)
test,
3.)
unlocked (only), and
4.) unlocked/withdrawn . A "racking" mechanism with a
low-force pump handle is used to move the moveable
drawout element between the connected, test, and un
locked positions. Since the pump handle is an integral part
of the racking mechanism, no auxiliary racking device or
Bus Stabs
Stationary Drawout Element
Bus Stab (In
Stationary
Drawout
Element}
Connected
Posrtion
Side View Shown
0
Exten
·
Rails
Test
Positron
tool is required . In the unlocked position the moveable
drawout element is disengaged from the racking mecha
nism. The moveable drawout element can be easily pulled
between the unlocked position and the withdrawn position.
A color coded indicator displays the position of the move
able drawout element.
I n addition to the integral pump handle, two levers are used
to control the movement of the moveable drawout element.
A single interlock lever automatically locks the moveable
drawout element when it reaches the test or the connected
position . The moveable drawout element is released to
move to the next position by simply pushing and releasing
the i nterlock lever.
Pushing and releasing the interlock
lever with the SB breaker contacts closed will open the
breaker.lt
is not necessary to hold the i nterlock lever to rack
the moveable drawout element. A directional shift lever
determines the direction the moveable drawout element
will move when the pump handle is pulled or pushed.
Secondary disconnect sliding terminal blocks for terminat
ing internal accessories are mounted on the sides of the
stationary and moveable drawout elements. The second
ary disconnects are mated as the moveable drawout
element is moved from the withdrawn position to the un
locked position . The terminal points of the secondary
disconnects are identified in the Accessories section.
Step-by-step instructions on operating the racking mech
anism are contained in the Operating Instructions section .
Position
Indicator
Directional
Shift Lever
(on-side panel)
Moveable Drawout Element
Moveable
Drawout
Element
7
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