Racking System Trip And Spring Release Interlocks; Racking Mechanism; Levering System Trip And Spring Release Interlocks; Grounding Contact - Eaton DST-2-15-VR+ Instruction Book

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DST-2-VR
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VR-Series Replacement Circuit Breaker
4.6.3 RACKING SYSTEM TRIP AND SPRING RELEASE
INTERLOCKS
4.6.3.1 INTERNAL ROTARY RACKING
An active interlock is provided to keep the breaker in a trip free
position when the breaker is between the test and fully connected
position; no adjustments are necessary. In addition to the active
interlock, two passive interlocks are provided; one to prevent
engaging the rotary racking handle into the breaker when the
breaker is closed, and one to prevent turning the rotary shaft in the
breaker when the breaker is closed.
4.6.3.2 LEVERING HANDLE RACKING (FLOOR TRIP /
INTERLOCK PEDAL)
The levering interlock prevents engaging a shut breaker with live
cell buss work or removing a breaker from the cell with charging
springs. The basic premise of this interlock is that no breaker should
be connected to or removed from cell primary circuitry when shut.
The levering interlock accomplishes this by providing a trip signal to
the breaker automatically from the floor trip whenever the Interlock
Pedal is depressed.

4.7 RACKING MECHANISM

4.7.1 LEVERING SYSTEM TRIP AND SPRING RELEASE
INTERLOCKS
The levering system tripping and spring release interlocks perform
the following:
a. Set the breaker mechanically trip-free during the first 4 inches
of travel into the cell and whenever the breaker receives a close
signal in an intermediate or the disconnect position.
b. Set the breaker in a safe condition (breaker open,springs
discharged) when removed from the cell.
c. Insert a mechanical trip signal to open a position switch
preventing energizing of the spring release coil whenever the
breaker is in an intermediate position.
d. Prevent inadvertent cycling (pumping) of the breaker between the
test and connect positions.
e. Prevent insertion of a closed breaker into the cell.
 WARNING
DO NOT FORCE THE BREAKER INTO THE CELL. DOING SO MAY DAMAGE
PARTS THEREBY RISKING DEATH, PERSONAL INJURY, AND/OR PROPERTY
DAMAGE.

4.8 GROUNDING CONTACT

The grounding contact is an assembly of spring loaded fingers which
ground the breaker frame (static ground) by engaging the switchgear
cell grounding bus when the breaker is racked into the cell. The
ground contact is located at the rear of the breaker near the floor
and visible from the back of the breaker when out of the cell.

4.9 MISCELLANEOUS ITEMS

4.9.1 OPERATIONS COUNTER

All DST-2-VR + breakers are equipped with a mechanical operations
counter (Figures 3.3). As the breaker opens, the linkage connected
to the pole shaft lever advances the counter reading by one.
18 Instruction Book IB182942EN May 2019 www.eaton.com