Powered by Safety
®
44
Operation
01.4IB.51000C
PowlVac® Metal-Clad Switchgear
5kV & 15kV
f. e
lectrIcAl
o
perAtIon
1. A one-line, or three-line diagram, and a
schematic diagram are prepared for each
metal-clad switchgear line-up. All diagrams
shall be thoroughly studied and completely
understood by the user before the
metal-clad switchgear is placed into service.
2. The reading of indicating, recording
instruments, and meters is common
knowledge to electrically trained personnel.
The use of instrument, rheostat control,
and governor motor control switches are
also common. Synchronizing switches
are usually provided on generator and
incoming line units with a synchronizing
switch contact, which is wired in series with
the circuit breaker control switch “close”
contact. The synchronizing switch should
always be turned “on” first, and the circuits
adjusted should be in synchronism as
indicated by the synchroscope before the
circuit breaker is closed.
3. A green light indicates that the circuit
breaker is open, and a red light indicates
that the circuit breaker is closed. For
the DC control schemes, the red light is
also arranged to supervise the trip coil
and indicate that the trip coil circuit has
continuity.
G. S
hutterS
Metal shutters (Figure 33, a) cover the primary
disconnect contacts when the removable
element is withdrawn from the compartment.
Figure 33 Shutters
a.
a. Shutters
Cam plates (Figure 36, c) located on each side
of the compartment are operated by the circuit
breaker crank arm rollers, which will then
operate the switchgear shutters. As the circuit
breaker is operated past the disconnected
position, the crank arm rollers will move the
cam plates rearward, and open the shutters
before the circuit breaker starts its forward
travel to the connected position. When the
circuit breaker is racked to the disconnected
position, the shutters are returned to their
closed position by springs attached to the cam
plates.
Provisions for padlocking the shutters in the
closed position are furnished on each of the
two cam plates. Padlocking either of the two
cam plates will deter opening of the shutters.