Eaton Cooper Power Series 8.3kV 50kA-Interrupting ELSP Under-Oil Backup Current-Limiting Fuse for Pad-Mounted Transformer

Product Specifications

Product Name: Eaton Cooper Power Series 8.3kV ELSP Under-Oil Backup Current-Limiting Fuse

Rated Voltage: 8.3 kV Class (Tested & Approved for up to 9.9 kV for 80A & 100A ratings)

Maximum Interrupting Rating: 50,000 A (50 kA) rms symmetrical

Type: Liquid-Immersed Oil-Type Backup Current-Limiting Fuse (Single Barrel Design)

Color: Dark Brown / Maroon Body with Bright Brass End Caps

Available Models & Current Ratings

• 8.3kV 30A Fuse: CBUC08030C100
• 8.3kV 40A Fuse: CBUC08040C100
• 8.3kV 50A Fuse: CBUC08050C100
• 8.3kV 65A Fuse: CBUC08065C100
• 8.3kV 80A Fuse: CBUC08080C100 (Certified for 9.9kV networks)
• 8.3kV 100A Fuse: CBUC08100C100 (Certified for 9.9kV networks)
• 8.3kV 125A Fuse: CBUC08125C100
• 8.3kV 150A Fuse: CBUC08150D100
• 8.3kV 165A Fuse: CBUC08165D100
• 8.3kV 180A Fuse: CBUC08180D100
• 8.3kV 250A Fuse: CBUC08250D100
• Parallel Configuration: Higher continuous current ratings (including 300A, 330A, 360A, and 500A) can be perfectly achieved by connecting two compatible ELSP fuses in parallel.

Material & Structural Characteristics

• Housing Cylinder: High-strength electrical grade filament-wound fiberglass housing to maintain total structural integrity during severe interruptions.
• Arc-Quenching Filler: Specific particle size, high-purity silica sand filler providing maximum heat absorption and exceptionally low energy let-thru.
• Element Design: Thermally stable pure silver element ribbons designed to minimize peak arc voltage levels during short-circuit clearing.
• End Connections: Solid copper end caps with durable brass inserts tapped for standard 1/4 inch – 20 x 1/2 inch lead hardware attachment.
• Sealing System: Advanced high-reliability double-sealing mechanism utilizing high-temperature Buna-N rubber gaskets and premium epoxy sealant.

Product Functions

1. High-Current Fault Isolation: Specifically engineered to detect, limit, and instantly clear massive destructive high-level internal faults within 8.3kV distribution equipment, protecting the upstream grid from catastrophic system stress.

2. Full-Range Fusing Coordination: Connected in series with a low-current primary device (such as a Bay-O-Net fuse or MagneX interrupter) to form a complete full-range protection system, leaving minor overloads to the replaceable link while instantly grabbing high-current failure energy.

3. Thermal Stress Minimization: The highly efficient current-limiting ribbons dramatically restrict both the energy let-thru (I²t) and peak current levels, safely preserving nearby transformer core and coil assemblies during internal insulation breakdown.

Key Features

1. Massive 50 kA Interruption Cap: Features an ultra-high short-circuit switching capacity built to reliably extinguish up to 50,000 A symmetrical rms fault currents, making it perfect for stiff municipal and industrial electrical grids.

2. Leak-Proof Double Sealing: Built with an advanced heavy-duty double-seal system to guarantee 100% fluid-tight integrity and zero silica sand leakage inside hot transformer mineral oil or FR3 fluid.

3. Gas-Free Element Support: Utilizes an inner mica spider element support that provides exceptional mechanical stability under severe thermal current cycling without generating gas or internal pressure buildup during arc clearance.

4. Permanent Identification Labeling: Every unit features an easy-to-read, permanent identification label containing full voltage metrics, exact catalog numbers, and standard industrial bar coding for smooth inventory tracking.

5. 100% Comprehensive Factory Testing: Every single production unit undergoes rigorous physical inspection, precise electrical resistance testing, specialized I²t validation, and ultra-sensitive Helium Mass Spectrometer Leak Testing.

Technical Parameter Specifications

• Max. Current: 250A Single Barrel (Up to 500A with parallel configurations)
• Max. Voltage: 8.3kV Class (9.9kV maximum certified application limit)
• Interrupting Capacity: 50,000A rms Symmetrical “C” Rated Backup protection
• Application: Pad-mounted Distribution Transformers, Substation Equipment, Wind/Solar Box-type Transformers (Compact Substations), Medium-Voltage Switchgear Cabinets.
• Key Materials: Filament-Wound Fiberglass Tube, High-Purity Silica Sand, Solid Copper End Caps, Buna-N Seals. Fully engineered and compliant with standard IEEE overcurrent protection specifications.