Oil-immersed, bayonet-type, current limiting fuses
and oil-immersed, bayonet type, overload fuses in
series with a partial range current-limiting fuse,
may be preferable to the drawout, drywell mounted,
current-limiting fuse because of the operating
characteristics, relative cost, and off-the-shelf
availability. Oil-immersed fuse operation can
contaminate the transformer oil, although numerous
fuse operations are required (on the order of 100)
before the contamination is significant.
Delete faulted circuit indicators unless required by
the operating installation.
**************************************************************************
The high-voltage compartment shall be dead-front construction. Primary
switching and protective devices shall include loadbreak switching,
[drawout, dry-well-mounted, current-limiting fuses] [oil-immersed,
current-limiting, bayonet-type fuses] [oil-immersed, bayonet-type, overload
fuse in series with a partial range current-limiting fuse], medium-voltage
separable loadbreak connectors, universal bushing wells and inserts or
integral one piece bushings and surge arresters. Fuses shall comply with
the requirements of paragraph METERING AND PROTECTIVE DEVICES. The switch
shall be mounted inside transformer tank with switch operating handle
located in high-voltage compartment and equipped with metal loop for hook
stick operation. Fuses shall be interlocked with switches so that fuses
can be removed only when the associated switch is in the "OPEN" position.
Adjacent to medium-voltage cable connections, a nameplate or equivalent
stencilled inscription shall be provided inscribed "DO NOT OPEN CABLE
CONNECTORS UNLESS SWITCH IS OPEN." Surge arresters shall be fully
insulated and configured to terminate on [the same bushing as the primary
cable by means of a loadbreak, feed-through bushing insert] [a second set
of high voltage bushings].
2.9.2.2
Load-Break Switch
**************************************************************************
NOTE: Choose one of the following options.
**************************************************************************
a. [Radial-feed oil-immersed type rated at [15] [_____] kV, [95] [_____]
kV BIL, with a continuous current rating and load-break rating of [200]
[_____] ampere, and a make-and-latch rating of 10,000 rms amperes
symmetrical. Locate the switch handle in the high-voltage compartment.]
b. [Loop feed sectionalizer switches: Provide three, two-position,
oil-immersed type switches to permit closed transition loop feed and
sectionalizing. Each switch shall be rated at [15] [_____] kV, [95]
[_____] kV BIL, with a continuous current rating and load-break rating of
[200] [_____] amperes, and a make-and-latch rating of 10,000 rms amperes
symmetrical. Locate the switch handle in the high-voltage compartment.]
Operation of switches shall be as follows:
ARRANGEMENT
DESCRIPTION OF
SWITCH POSITION
#
SWITCH
LINE A SW
LINE B SW
XFMR SW
ARRANGEMENT
OPEN CLOSE
OPEN CLOSE
OPEN CLOSE
1
Line A connected to
X
X
X
Line B and both
SECTION 16375A
Page 33
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