23
Instruction Book
IB182942EN July 2018 www.eaton.com
DST-2-VR
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VR-Series
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Replacement Circuit Breaker
Figurt 5.4. DST-2-7.5-VR
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in Conntct Position
g. (Domestic Version) In the “test” position, the breaker can be
operated manually and electrically, thus allowing maintenance
tests or checks. To operate the breaker electrically, the secondary
control block must be engaged at this time. The slider is located
on the lower right hand area of the circuit breaker frame. If
electrical testing is desired at this stage, engage the secondary
control block slider by releasing the slide latch and pushing
the slider toward the rear several inches. Push firmly on the
front side of the slider until the contact block engages with the
corresponding cell receptacle. Return the manual motor cutoff
switch to the “on” position. The spring charging motor will begin
to run and charge the closing spring. The breaker is now in
the “test” position, with control voltage applied, and ready for
electrical or manual testing.
g. (Canadian Version) In the test position, the breaker can be
operated manually and electrically, thus allowing maintenance
tests or checks. To operate the breaker electrically, the secondary
block must be engaged. On Canadian versions, the secondary
block for 250Vdc versions is located on the lower, rear, center of
the breaker. Other Canadian versions, the secondary disconnect
operates in a manner similar to the domestic US models detailed
above. The secondary block automatically engages in the test
position. Return the manual motor cut-off switch to the “on”
position. The spring charging motor will begin to run and charge
the closing springs. The breaker is now in the “test” position, with
control voltage applied, and ready for manual or electrical testing.
(* For DST-2-7.5-VR
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with centered secondary disconnect block)
h. To install the breaker in the connected position the levering
handle will have to be used. Insure the breaker is open and
engage the levering handle with the breaker and floor levering
cutouts. (See Figure 5.5)
i. Depress the Interlock Pedal and start levering in the breaker by
shifting the levering handle back and forth. Once movement has
started, the pedal should be released. The closing springs may be
in the charged state but the internal PS switch will open circuit
the close spring release coil (preventing an electrical close).
At this point any attempt to mechanically close the breaker will
cause a trip-free operation with no recharging of the closing
springs (PS2 has open-circuited the charging motor circuit and
the Interlock Pedal operation has automatically turned the motor
cutoff switch to “off”). As advancement into the cell continues,
the primary voltage source shutters will open allowing the breaker
stabs to engage with the source.
j. Continue moving the breaker into the cell using the levering
handle from the test position until a mechanical stop is reached.
This is the fully engaged or connected position. The connect
position can be verified by the inability to move the breaker
in or out, the Interlock Pedal is up and has released the trip
mechanism, and the cell label “operating” is visible on the floor of
the cell in front of the breaker’s left front wheel. Manually return
the motor cutoff switch to the “on” position. The breaker is now
ready for service.
5.10.3 REMOVAL PROCEDURE (LEVERING-IN VERSION)
To remove the breaker from the cell it must be in the open position.
Insure the breaker is open and engage the levering handle.
The Interlock Pedal must be depressed which will raise the trip
mechanism and trip the breaker. Move the breaker out using the
levering handle illustrated in Figure 5.5. The breaker will start coming
out of the cell before the main stabs are disconnected and will be in
a non-operable mode and will go through a trip-free operation if any
attempt to close it is made in the intermediate position. Also, the
secondary control block will disengage automatically before the main
stabs are disconnected.
otte:
N
(Canadian Version) The secondary block will remain connected until the
breaker is removed from the test position.
The shutters will close after the main stabs have cleared, isolating
the breaker from its source. Continue levering out until the position
indicator on the floor of the cell shows test and the Interlock Pedal
rises to lock the breaker in position. At this time you are in the test
d. Push the circuit breaker into the cell until all the wheels are on
the guide rails and the spring discharge linkage has not cycled.
(For Canadian breakers, the interlock plunger will rest in the
first cell position.) No mechanical stop will be reached. This is
the “disconnect” position and the breaker can still be operated
because there is no interface of the cell floor interlocks with
breaker interlock linkage. No cell labeling is provided to verify this
position.
e. Depress the pedal and push or lever the breaker further into the
cell. (Figure 5.3)
otte:
N
Depressing of the Interlock Pedal automatically positions the motor
cutoff switch to “off”.
f. Once movement has started, the Interlock Pedal should be
released if depressed. The levering handle may be required to
move the breaker completely into the test position and its use is
illustrated in Figure 5.3. An audible click of the interlock plunger
engaging the interlock rail will be observed when moving from
the disconnect position. The Interlock Pedal will travel down at
the beginning of movement and rapidly rise to lock the breaker in
the test position at the end of the normal travel from disconnect
to test. The movement of the handle provides an open signal
that remains throughout all intermediate breaker positions and
the floor trip will be combined with a closing signal between the
disconnect and test position to discharge the closing springs.
The breaker remains in the trip-free state until the test position is
reached. The test position can be verified by the inability to move
the breaker in or out, the Interlock Pedal is in the up position, and
the cell label “test” is visible on the floor of the cell in front of the
breaker’s left front wheel.
