Eaton Cooper Power Series ELSP 38 kV Under-Oil Current-Limiting Backup Fuse for Pad-Mounted Transformer

Product Specifications

Product Name: Eaton Cooper Power Series 38kV ELSP Under-Oil Backup Current-Limiting Fuse

Rated Voltage: 38 kV Class (Engineered for ultra-high medium-voltage distribution environments)

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

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

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

Available Models & Current Ratings

• 38kV 50A Fuse: Catalog Number CBUC38050D100 (3.0-inch tube diameter, 15.95-inch barrel length)
• 38kV 65A Fuse: Catalog Number CBUC38065D100 (3.0-inch tube diameter, 15.95-inch barrel length)
• 38kV 80A Fuse: Catalog Number CBUC38080D100 (3.0-inch tube diameter, 19.2-inch barrel length)
• 38kV 100A Fuse: Catalog Number CBUC38100D100 (3.0-inch tube diameter, 19.2-inch barrel length)
• 38kV 120A Fuse: Catalog Number CBUC38120D100 (3.0-inch tube diameter, 21.9-inch barrel length)
• 38kV 140A Fuse: Catalog Number CBUC38140D100 (3.0-inch tube diameter, 24.7-inch barrel length)
• Application Note: Continuous high-current capacity can be perfectly customized based on original TCC clearing curves by utilizing parallel configurations.

Material & Structural Characteristics

• Housing Cylinder: High-strength electrical grade filament-wound 3-inch fiberglass housing to maintain total structural integrity during severe 50 kA high-fault interruptions.
• Arc-Quenching Filler: Specific particle size, high-purity silica sand filler providing maximum heat absorption, exceptional compaction, and low energy let-thru.
• Element Design: Thermally stable pure silver element ribbons wound on an internal mica spider support, minimizing peak arc voltage levels during intense 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 to prevent oil ingress or filler leakage.

Product Functions

1. Extreme High-Current Fault Isolation: Specifically engineered to detect, limit, and instantly extinguish massive destructive high-level internal faults up to 50,000 A within 38kV 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 38 kV Bay-O-Net fuse assembly) to form a complete full-range protection system, leaving minor overloads to the replaceable link while instantly grabbing high-current failure energy.

3. Thermal & Mechanical Stress Minimization: The highly efficient current-limiting silver 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. Ultimate 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 networks.

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 environments.

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: 140A Single Barrel in 3-inch format design
• Max. Voltage: 38kV Class design standard
• 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.