JDZ-250E Cooper/Bussmann, JDZ-250E Datasheet - Page 19

• Manufacturer Part Number: JDZ-250E
• Description: Fuses JDZ-250E
• Manufacturer: Cooper/Bussmann
• Type: E-rated Fuse for Transformerr
• Series: JDZr

Specifications of JDZ-250E

• Current Rating: 250 Amps
• Voltage Rating: 8.3 KVolts
• Termination Style: Cartridge
• Dimensions: 15.88 mm L
• Product: Medium Voltage Fuse
• Interrupt Rating: 80000 Amps
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: JDZ-250E

BBU
Specifications
Description: Boric
acid fuses for power
transformers, feeder
circuits, distribution
transformers, metal-
enclosed and pad-
mounted switchgear
Construction:
Principle parts of the
replaceable BBU fuse
unit are shown in the
cross section views. A
glass epoxy tube
encloses the assembly
containing the silver
fuse element, arcing
rod, boric acid cylinder
and spring. Using a
pure silver element and nichrome wire
strain element makes the BBU less
susceptible to failure caused by vibration,
corona corrosion and fuse element
aging. The components are housed in a
fiberglass reinforced resin tube with
plated copper contacts. BBU fuses can
directly replace competitive equivalent
units.
Operation: The BBU fuse uses boric
acid to create the de-ionizing action to
interrupt the arc. At high temperatures,
boric acid decomposes to produce a
blast of water vapor and inert boric
anhydride. Fault interruption is achieved
by an arcing rod and a charged spring
Element
Medium Voltage Fuses
Melts
BBU Boric Acid Fuses
Rod withdraws,
and vaporizing
elongating arc
Boric Acid
current zero
For product data sheets, visit www.cooperbussmann.com/datasheets/ulcsa
arc at first
quenches
Vapor
• E (Standard)
• K (Fast), and
• SE (Slow)
Volts: — The maximum voltage rating of
that elongate the arc through a boric
acid chamber upon release by the fuse
element to interrupt short circuits within
one-half cycle and prevent the arc from
re-striking after a current zero.
BBU End Fittings: BBU end fittings
complete the electrical connection
between the fuse unit and the fuse
mounting. Positioned on the top and
bottom of the fuse, unit end fittings can
be used over again if they remain
undamaged. They are completely
interchangeable with other
manufacturers’ equivalent fuse units and
mountings.
Indoor Fittings: The indoor end fittings
are made of high-impact plastic and
high-conducting copper alloy. The blown
fuse indicator, located on the top end
fitting, provides visual indication of a
faulted fuse unit. When engaged into the
mounting, the spring-loaded plastic
mounting handle actuates the latch
mechanism and readily accepts a
hookstick to install or remove the
assembled fuse unit.
The bottom indoor fitting is threaded to
accept a muffler constructed of a plated
steel housing, containing copper mesh
screening, that absorbs and contains the
noise and exhaust materials during a
fault condition, and prevents
contamination of indoor components and
mechanisms located within the
switchgear. Containment also prevents
accidental flash-over from phase-to-
phase or phase-to-ground by limiting
airborne particles and gases.
BBU Melt Curve Constructions: The
BBU fuse is offered in three
constructions to meet specific melt
curves for an application. The
construction is designated in the Catalog
Number suffix as follows;
The curves for the SE construction are
less inverse and allow for more of a
time-delay at high currents. Consult
Cooper Bussmann for application
assistance.
Ratings:
the BBU fuse is the highest
RMS voltage at which the fuse
• Voltage ratings of up to 38kV coupled
• Time-current characteristics allow for
• Provides replacement of a variety of
• Power and Distribution Transformer
• Medium Voltage Feeder Circuit
• Distribution Transformers
• Medium Voltage Metal-enclosed
• Medium Voltage Pad-mounted Switches
Amps:— The continuous amp rating of a
IR:—
Features and Benefits
Typical Applications
with ratings to 200A provide a wide
range of circuit protection.
easier coordination with downstream
devices.
existing systems.
Protection
Protection
Switchgear
BBU fuses have interrupting
BBU fuse should equal or
exceed the maximum load
current where the fuse is
applied. They are designed to
carry their rated continuous
current without exceeding the
temperature rise outlined in
NEMA and ANSI standards. The
BBU is available with
continuous current ratings up to
200 amps The current ratings
carry an “E” designation as
defined by ANSI and NEMA.
For example, the current
responsive element rated 100E
amps or below will melt in 300
seconds at an RMS current
within the range of 200 to 240
percent of the continuous
current ratings. Above 100E
amps, melting takes place in
600 seconds at an RMS current
within the range of 220 to 264
percent of the continuous
current rating.
capabilities from 10kA to 14kA
symmetrical.
is designed to operate. Its
dielectric withstand level
corresponds to insulation levels
of power class equipment, thus
the name “power fuse.”
Maximum voltage ratings for
BBU fuses are: 17kV, 27kV and
38kV.
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