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15
Equipment Description
01.4IB.51000C
When fuses are disconnected, they are at a
safe striking distance from all live parts of the
switchgear. In addition, a grounding device is
provided which contacts the fuses after they
are disconnected, effectively removing any
static charge from the fuses. In this position,
the fuses may be safely removed and replaced.
The primary disconnecting devices are capable
of interrupting transformer magnetizing
current, but should not be used to interrupt
load current. Mechanical or key interlocks are
applied to prevent operating the disconnecting
device while the load is connected. This is
generally accomplished by interlocking so
that the transformer secondary breaker must
be locked in the open position before the
rollout carriage can be moved to connect or
disconnect the primary disconnect device in
the switchgear.
When the fuse or control power transformer
rollout carriage is in the disconnected position,
the rear barrier of the carriage effectively deters
access to the stationary primary disconnect
devices mounted in the compartment behind
the rollout carriage. These stationary primary
disconnect devices may remain energized.
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Ring-type current transformers (Figure 4, c)
are positioned around the stationary primary
disconnect devices. These current transformers
are removable from the front and may be
located on upper and/or lower primary
disconnect supports. When necessary, special
current transformers may be mounted in the
line module.
Prior to adjustments, servicing, maintenance,
or any act requiring the operator to make
physical contact with the equipment, the
power source must be disconnected and the
equipment grounded. Failure to do so may
result in death or serious injury.
!
WARNING
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The main bus, main bus taps, and ground bus
conductors are made of copper. The main
bus, main bus joints, and taps are insulated.
This insulation provides protection against the
propagation of arcing ground faults, but does
not offer personnel protection against shock
hazards. The bolted connections are
silver-plated or tin-plated.
The main bus supports of a 15kV class
metal-clad switchgear are of molded epoxy.
The main bus supports of a 5kV class
metal-clad switchgear are of polyester
laminate.