25
Instruction Book
IB182942EN July 2018 www.eaton.com
DST-2-VR
+
VR-Series
+
Replacement Circuit Breaker
5.11.3 5kV Rtmoval Proctdurt (DST-2-5-VR
+
250, Domtstic
and Canadian Rotary Racking Vtrsion)
a. To remove the circuit breaker from the cell, verify that the breaker
is in the “OPEN” position and the motor cutoff switch is in the
“OFF” position. Place the rotary racking handle on the rotary
racking hex head. Rotate the racking handle counter-clockwise
to move the circuit breaker from the “connect” position to the
“Disc/Test” position. As the circuit breaker leaves the “connect”
position, the shutters will start to close after the primary
disconnects have cleared, isolating the breaker from the line and
load connections. Continue rotating the racking handle counter-
clockwise until the position indicators on the breaker indicate
the “Disc/Test” position and it is not possible to turn the racking
handle with normal force. (Damage to the circuit breaker will
occur if the racking handle is forced counter-clockwise beyond this
point of resistance.) In this position, the secondary disconnect
control power connections can be re-connected so the breaker
can be operated either electrically or manually. Remove the
racking handle prior to performing and breaker tests.
otte:
N
For Canadian versions with separate “disconnect” and “test” positions,
it will stop first at the “test” position. Electrical and mechanical tests of the
circuit breaker can be performed in this position. Remove the racking handle
prior to performing any breaker test.
b. If the circuit breaker is to be withdrawn from the cell, remove the
rotary racking handle, and depress the interlock petal while pulling
the breaker out of the circuit breaker compartment using the
handles on the front of the breaker.
otte:
N
For Canadian versions with separate “disconnect” and “test”
positions, it will be necessary to remove the racking handle, step on the
interlock petal and pull the circuit breaker to the next mechanical stop. At
that mechanical stop, the circuit breaker is in the “disconnect” position.
Stepping on the interlock petal again will release the circuit breaker so that
it can be pulled to the fully withdrawn position and out of the circuit breaker
compartment.
c. During this travel from the “Disc/Test” position, the circuit
breaker closing springs will discharge automatically with a loud
noise similar to the noise made when the circuit breaker is
closed. At this point, the breaker will be open with the springs
discharged..
otte:
N
If through-the-door racking is desired, the cell door must be modified
by cutting a hole in it which aligns with the rotary racking hex head. A sub-
cover must also be installed to block access to the racking hex head until
required. Even with this modification, it will be necessary to position the
circuit breaker compartment door open. Only after doing that, can closed door
racking be performed from the “test” position to the “connect” position.
The motor disconnect switch can be accessed while the door is open for
installation or removal process, or flipped on or off with the racking handle.
5.11.4 15kV Instrtion Proctdurt (DST-2-15-VR
+
500/750
Domtstic and Canadian Rotary Racking Vtrsion)
a. Verify that the circuit breaker racking system is in the fully
withdrawn position. This is an important step, as breaker
maintenance outside the breaker compartment may have required
that the rotary racking be racked-in so that the circuit breaker
could be closed. It must be returned to the fully withdrawn
condition prior to insertion in the circuit breaker compartment.
b. From the withdrawn position, align the center groove of the
breaker wheels with the guide rails of the cell.
c. Check that the closing spring status is located on the lower cover
where it can be easily accessed (See Figure Set 3.3). Position the
switch to “OFF” before inserting the breaker into the cell.
d. Push the circuit breaker into the cell until the mechanical stop is
reached; this will be indicated by an audible click. At this point,
the front plunger has fallen in the front slot of the guide rail. In
this position, the breaker can be operated. This position can also
be verified by noting that the foot petal moves upward as the
mechanical stop drops into the slot in the floor mounted rail. The
racking hex head access handle is also released so that it can be
raised for rotary racking. (Figure 5.5)
Figurt 5.6. Lifting Racking Acctss Handlt
otte:
N
For Canadian versions with separate “disconnect” and “test” positions,
it will be necessary to step on the racking unlock petal and push the circuit
breaker to the next mechanical stop. At that mechanical stop, the circuit
breaker is in the “test” position. Provisions in the racking system prevents
the circuit breaker from being un-latched and pushed beyond this mechanical
stop; any additional movement toward the “connect” position must be
achieved with the rotary racking feature. With the circuit breaker in the “test”
position, item (e.) below can then be performed.
e. In the “Disc/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 energize and charge the closing spring.
The breaker is now in the “Test” position, with control voltage
applied, and ready for electrical or manual testing.
NOTICE
ONCE THE SECONDARY DISCONNECT BLOCK IS ENGAGED IN THE “TEST”
POSITION, IT WILL REMAIN CONNECTED THROUGHOUT FURTHER INWARD
MOVEMENT AS THE BREAKER ADVANCES FROM THE “DISC/TEST” TO THE
“CONNECT” POSITION.
THE SPRING CHARGING MOTOR WILL ENERGIZE, IF THE MOTOR CUT-OFF
SWITCH IS IN THE “ON” POSITION (FIGURE SET 3.3), AND CHARGE THE
CLOSING SPRINGS AS THE SECONDARY CONNECTION IS MADE AS LONG
AS CONTROL POWER IS AVAILABLE.
f. From the “Disc/Test” position, the breaker can be advanced to the
“connect” position. It is NOT necessary to step on the racking
unlock foot petal when the circuit breaker is in this position. Lift
the racking access handle by pulling it up and over to the right
to gain access to the racking hex head.
(This sttp must bt
ptrformtd prior to clostd door racking.)
The handle will be
retained allowing full exposure of the racking hex head. PLace
the rotary racking handle onto the rotary racking hex head. Turn
the rotary racking handle clockwise until the “connect” position
is reached and the handle can no longer be turned, as indicated
on the switchgear floor mounted breaker position indicator, Figure
5.6.
Do not forct tht rotary racking handlt btyond this point
as brtaktr damagt will occur.
