9
CAUTION:
THE CIRCUIT BREAKER HAS
BEEN SHIPPED IN THE CLOSED POSITION.
After removing packing material, open the
breaker by pushing in firmly on the manual trip
button (Figure 2, Item 8), while keeping hands
away from moving parts. A safe way to do this
is to push on the trip button with the round side
of the maintenaince handle. Verify that the op-
eration counter advances one count.
Closing and opening springs are now in their
discharged positions. Check this by first press-
ing the manual close button, then the manual
trip button. The indicator flags on the front of
the breaker should show “OPEN” and
“DISCHGD”.
All mechanical and electrical checks listed in
Chapter 4 should be completed before putting
breakers in service.
3-6 Safety Interlocks
Each PowerVac
®
VL vacuum circuit breaker is
provided with the following interlocks:
Positive Interlock System
The purpose of the positive interlock is to pre-
vent moving the breaker to or from the connected
position while the main contacts are closed, and
to prevent closing the contacts unless the
breaker is in the fully connected position. These
important safety features are achieved by means
of the positive interlock
roller on the right side
of the breaker and positive interlock cam and
stationary “flag” in the switchgear cell.
PowerVac
®
5kV Vertical Lift
Chapter 3. Receiving, Handling & Storage
A major goal in the design of switchgear has
always been the interchangeabililty of break-
ers. GE Switchgear has been very successful
in achieving that goal for many years. Analy-
sis of instruction book adjustments, shop tol-
erances, and service advice letters issued in
recent years, however, has demonstrated that
tolerances in switchgear equipment installed
and presently operating can change, result-
ing in situations where it is impossible to meet
all adjustments. Also, when an adjustment
is brought into specification it can cause a
problem with another interface or adjustment.
Although GE has made every effort to assure
interchangability and satisfactory interface with
existing equipment. Older equipment and field
modifications that may have been made over
the years, may require additional procedures
before the new vacuum breaker can be installed
in the cubicle. At a minimum, all breaker-to-
switchgear interfaces as explained in this sec-
tion should be verified for proper operation prior
to energizing. The interfacing parts on all rat-
ings of type AM breakers are functionally the
same.
The following section defines the essen-
tial dimensions relating to the interfacing
elements of the breaker and switchgear,
to assure reliable performance. Some of
these elements also affect the other im-
portant interfaces required for reliable op-
eration of the equipment, such as:
1. Positive interlock safety feature.
2. Mechanism operation.
3. Primary disconnect penetration.
4. Secondary coupler penetration.
Figure 4.
Positive
Interlock
Figure 3. Manual Trip & Close
