15
Instruction Book
IB02707112E
August 2015
50/75VCPW-VSR
Breaker To Vacuum Starter Replacement Unit
EATON CORPORATION www.eaton.com
4.3 SECONDARY DISCONNECTS
The VSR control circuit is connected to the switchgear control
through a multi-contact block (See Section 3 for component
location). The movable secondary control contacts mounted on the
unit are self-aligning, line-contact, slip-type connectors. The multiple
finger arrangement on the unit makes contact with a stationary
mounted element. The contact surfaces on the stationary element
are recessed to prevent accidental short-circuiting of the control
circuits.
These secondary disconnects mate in both the operating and test
positions. No special jumper is required.
Mechanical stops prevent over-travel and avoid damage to the
disconnecting devices when the unit is racked into operating
position.
WARNING
INTERLOCKS ARE PROTECTIVE DEVICES FOR PERSONNEL AND
EQUIPMENT. DO NOT BYPASS, MODIFY, OR MAKE INOPERATIVE ANY
INTERLOCKS. DOING SO COULD CAUSE DEATH, SERIOUS PERSONNEL
INJURY, AND/OR PROPERTY DAMAGE.
4.4 INTERLOCKS
There are several interlocks built into the VSR-Series vacuum
starter replacements. Each of these interlocks, though different in
form, duplicate or exceed in function that of the original breaker.
These interlocks exist to safeguard personnel and equipment. The
basic premise behind the interlocking arrangement on the vacuum
replacement starter is that the starter must not be inserted into or
remove from the live circuit while the main contacts are closed.
Also considered in the interlocking is that the starter should pose no
greater risk than necessary to the operator in or out of the cell.
4.5 RACKING-IN INTERLOCK
The racking-in interlock is designed to prevent moving the starter
into or out of the Connect position, if the starter contacts are closed.
VCPW-VSR interlocks are completely compatible with the existing
racking system located in the existing VCP-W assembly structure.
VCPW-VSR starters utilize a interlock design that is very similar to
the design used on VCP-W breakers.
4.6 RACKING MECHANISM
The purpose of the racking device is to move the VSR between the
TEST and CONNECTED positions. For the VCPW-VSR, the device
is a drive screw and drive nut. Although the device is mounted
in the switchgear compartment, a brief description here will help
understand the operation. For additional information on the insertion
and removal of a VSR from its compartment refer to the insertion
and removal sections in this manual.
The racking device consists of a drive screw, a drive nut, two side
rails and a sliding cage. In the TEST position, the nut is all the way
to the front. As the VSR is pushed in, the racking latch snaps on the
nut. Turning the crank clockwise while pushing forward advances the
VSR toward the CONNECTED position. During this travel, the floor
tripper TRIP roller is lifted up holding the VSR trip free. When the
VSR reaches the CONNECTED position, the crank cannot be turned
any further. A red flag indicates that the VCPW-VSR is fully engaged.
If the VSR is closed in the CONNECTED position, engagement of
the slider will open the contactor and permit use of the racking
crank. After tripping the VSR, the racking crank can be engaged and
the VSR withdrawn to the TEST position by turning the racking crank
counterclockwise. This position is indicated by no further motion of
the crank.
The VCPW-VSR racking latch can be disengaged only when the VSR
is in the TEST position by lifting the latch release. As the VSR is
withdrawn, it comes out with the contacts open.
4.7 GROUND CONTACT
The ground contact is an assembly of spring loaded fingers for all
VCPW-VSR Vacuum Motor Starter Replacement designs providing a
disconnectable means for grounding the starter chassis, after it has
been inserted into a switchgear cell (Figure 4.6). The ground contact
is located on the underside of the chassis next to the secondary
contact block. An extension of the switchgear ground bus is secured
to the cell floor in such a position to engage the ground contact
automatically, when the starter is pushed into the Test position. It
remains engaged in all positions from Test to and including Connect.
4.8 OPERATIONS COUNTER
All VCPW-VSR Vacuum Motor Starter Replacement Units are
equipped with a mechanical operations counter (Figures 3.3). As the
starter opens, the counter advances the reading by one.
Figurt 4.6. GrNund CNnoaco
