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Instruction Book
Page 22
Effective: March 2007
5-1.5 PHASE BARRIERS
WARNING
DO NOT PLACE THE BREAKER IN ITS
COMPARTMENT WITHOUT THE PHASE BARRIERS IN
PLACE. THE ABSENCE OF BARRIERS CAN CAUSE A
CATASTROPHIC FAILURE DURING AN
INTERRUPTION OR OPERATION, CAUSING DEATH,
SEVERE PERSONAL INJURY OR PROPERTY
DAMAGE.
Phase barriers on all DHP-VR breakers are made of
glass polyester. They are all secured in place by bolts,
and are part of the breaker assembly. The 5kV. DHPVR
breaker utilizes 4 barriers, while the 7.5 or 15 kV. designs
utilize 5 barriers (Figures 3-3 and 3-5).
5-2 STORED ENERGY MECHANISM
WARNING
KEEP HANDS AND FINGERS AWAY FROM THE
BREAKER'S INTERNAL PARTS WHILE THE BREAK-
ER CONTACTS ARE CLOSED OR THE CLOSING
SPRINGS ARE CHARGED. THE BREAKER
CONTACTS MAY OPEN OR THE CLOSING SPRINGS
DISCHARGE CAUSING A CRUSHING INJURY.
DISCHARGE THE SPRINGS AND OPEN THE BREAK-
ER BEFORE PERFORMING ANY MAINTENANCE,
INSPECTION OR REPAIR ON THE BREAKER.
The spring stored energy operating mechanism is
arranged vertically in front of all DHP-VR breakers. It
includes all the elements for storing the energy, closing
and tripping of the breaker, as well as manual and
electrical controls. The manual controls are all front
accessible. Motion to close and open the interrupter
contacts is provided through operating rods connecting
the mechanism pole shaft to the bell cranks of the
interrupter assemblies (Figures 5-3 and 5-4).
5-2.1 OPERATION OF STORED ENERGY MECHANISM
The mechanism stores the closing energy by charging
the closing springs. The mechanism may rest in any one
of the four positions shown in Figure 5-5 and as follows:
a. Breaker open, closing springs discharged
b. Breaker open, closing springs charged
c. Breaker closed, closing springs discharged
d. Breaker closed, closing springs charged
Courtesy of NationalSwitchgear.com
5-2.2 CHARGING
Figure 5-6 is a schematic view of the spring charging
parts of the stored energy mechanism.
The major component of the mechanism is a cam shaft
assembly which consists of a drive shaft to which are
attached two closing spring cranks (one on each end),
the closing cam, drive plates, and a free-wheeling
ratchet wheel. The ratchet wheel is actuated by an
oscillating mechanism driven by the motor eccentric. As
the ratchet wheel rotates, it pushes the drive plates
which, in turn, rotate the closing spring cranks and the
closing cam with it.
The closing spring cranks have spring ends connected
to them, which are in turn coupled to the closing springs.
As the cranks rotate, the closing springs are charged.
When the closing springs are completely charged, the
spring cranks go over dead center, and the closing stop
roller comes against the spring release latch. The
closing springs are now held in the fully charged
position.
Closing springs may also be charged manually. Insert
the maintenance tool in the manual charging socket
(Figures 3-2 and 3-4). Move it up and down
approximately 36 times until a clicking sound is heard,
and the closing springs charging indicator indicates
"Charged". Any further motion of the maintenance tool
will result in free wheeling of the ratchet wheel.
5-2.3 CLOSING OPERATION
Figure 5-5 shows the positions of the closing cam and
tripping linkage. Note that in Figure 5-5a, in which the
breaker is open and the closing springs are discharged,
the trip "D" shaft and the trip latch are in the unlatched
position.
Once charged, as in Figure 5-5b the closing springs can
be released to close the breaker by moving the spring
release latch out of the way. This is done electrically or
manually by depressing the spring release lever, which
turns the spring release latch out of the way of the closing
stop roller. The force of the closing spring rotates the cam
shaft through the spring cranks. The closing cam, being
attached to the cam shaft, in turn rotates the pole shaft
through the main link to close the breaker.
In Figure 5-5c the linkage is shown with the breaker in
the closed position before the closing sprigs have been
recharged. Interference of the trip "D" shaft with the trip
latch prevents linkage from collapsing, and the breaker is
held closed.
For more information visit:
www.EatonElectrical.com
I.B6513C80G
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