Volume 12—Aftermarket, Renewal Parts and Life Extension Solutions CA08100014E—October 2016 www.eaton.com V12-T18-5
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Medium Voltage Fuses
Expulsion Fuses
Expulsion Fuses
RBA—Refillable Boric Acid
RDB—Refillable Dropout Boric Acid
DBU—Dropout Boric Acid—
Interchangeable with S&C’s SMU-20
Product Description
Eaton expulsion fuses
use boric acid as the
interrupting medium. Under
a fault condition, arc heat
decomposes the boric acid,
which produces gases and
boric anhydride. The water
vapor blast extinguishes the
arc in a deionizing action
and exits from the bottom
of the fuse.
Type RBA indoor expulsion
fuses are fitted with a filter
or condenser that moderates
the discharge exhaust. The
discharge filter limits the
exhaust to a small and
relatively inert amount of
gas and lowers the noise
level without affecting the
fuse interrupting rating.
Steam discharge, that can
affect the interrupting, is fully
restricted by the condenser.
Each type RDB outdoor
dropout fuse includes an
ejector pin that is forced
through the top of the fuse.
The ejector pin releases a
latch on the mounting and the
fuseholder is kicked outward
and swings into the dropout
position, through 180° with a
vertical mounting, or 90° with
an underslug mounting.
Refill units can be field
installed into RBA and RDB
expulsion fuses. Once the old
unit has been removed, the
separately purchased unit
can be easily installed into
the fuse holder.
General Information
Applications
Expulsion technologies can
be used to meet a number
of fuse applications. Typical
applications for utility,
industrial
construction and
OEM customers include:
●
Feeder circuit
sectionalizing
●
Fused switches
●
Power transformers
●
Substation service
transformers
●
DIP poles
●
Potential transformers
●
Substation capacitor banks
Accessories
The following accessories are
available for expulsion fuses:
Mountings include a base,
porcelain or glass polyester
insulators and live parts. They
help enable the fuse to be
safely attached to the gear.
Mountings can be either
disconnect, nondisconnect
or dropout. Fuses may be
vertical or underhung.
Live Parts attach the fuse
to the mountings and are
considered part of the
mounting. All parts above
the insulators are live parts.
End Fittings must be
mounted on DBU fuse units
to enable them to be fitted
into the mounting.
Filters and Condensers
are for indoor applications of
RBA expulsion fuses. They
confine the arc within the
fuse and substantially reduce
the noise and exhaust when
the fuse interrupts.
Mufflers are used with DBU
fuses in indoor applications
to virtually eliminate offensive
noise and exhaust gases
when the fuse interrupts.
