ABB Trans-Guard OS Shorty 38 kV Under-Oil Current-Limiting Backup Fuse for Pad-Mounted Transformer

Product Specifications

Product Name: ABB Trans-Guard OS Shorty Under-Oil Backup Current-Limiting Fuse

Rated Voltage: 38.0 kV Class (Maximum rated voltage up to 38.0 kV)

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 65A Fuse: Catalog Number HTSS372065CN (3.3-inch outer diameter, 18.3-inch body length)
• 38kV 80A Fuse: Catalog Number HTSS372080CN (3.3-inch outer diameter, 18.3-inch body length)
• 38kV 100A Fuse: Catalog Number HTSS372100CN (3.3-inch outer diameter, 18.3-inch body length)
• 38kV 125A Fuse: Catalog Number HTSS372125CN (3.3-inch outer diameter, 18.3-inch body length)
• 38kV 140A Fuse: Catalog Number HTSS372140CN (3.3-inch outer diameter, 21.0-inch body length)
• 38kV 165A Fuse: Catalog Number HTSS372165CN (3.3-inch outer diameter, 21.0-inch body length)
• 38kV 200A Fuse: Catalog Number HTSS372200CN (3.3-inch outer diameter, 21.0-inch body length)
• Parallel Configuration: Higher continuous current configurations can be engineered by combining multiple units to satisfy specific transformer capacity expansion needs.

Material & Structural Characteristics

• Housing Cylinder: High-strength electrical grade filament-wound fiberglass housing to maintain total structural stability against massive internal pressures during severe fault interruptions.
• Arc-Quenching Filler: Compacted high-purity silica sand filler with targeted particle sizing to deliver maximum thermal energy absorption and extremely low peak arc voltage let-thru.
• Element Design: Thermally stable pure silver element ribbons wrapped around a gas-free inner mica spider support matrix, ensuring reliable element performance under cyclic loading.
• End Connections: Heavy-duty solid copper end caps with durable brass inserts tapped for standard under-oil mounting hardware attachment.
• Sealing System: Advanced high-reliability double-sealing mechanism utilizing high-temperature Buna-N rubber gaskets and premium epoxy sealant to guarantee zero sand or fluid leakage.

Product Functions

1. Sub-surface High-Current Fault Isolation: Specifically engineered to immediately detect, limit, and clear massive destructive low-impedance faults within 38kV distribution equipment, minimizing system duration of arcing.

2. Two-Part Fusing Coordination: Formulates a full-range coordinated scheme when applied in series with an under-oil overload links or bay-o-net device, leaving low-magnitude currents to the expulsion link while instantly clearing massive short circuits.

3. Energy Let-Thru Minimization: Acts as an electrical buffer that strictly limits the total energy (I²t) passing into the fault source to a level well below the transformer tank’s withstand capability.

Key Features

1. Ultimate 50 kA Interruption Cap: Engineered with a high switching capability rated up to 50,000 A symmetrical rms, preventing rising available fault currents from damaging electrical infrastructure.

2. Tank Rupture Prevention: Greatly isolates internal arc breakdowns to reduce the high risks of destructive equipment failure, such as transformer tank ruptures or loose accessories.

3. Space-Saving Compact Geometry: Proudly manufactured with a sleek physical volume, making it highly suitable for installation inside space-constrained single-phase or compact distribution transformers.

4. Permanent Identification Labeling: Equipped with an easy-to-read, rugged product label that clearly marks exact voltage metrics, current ratings, and unique catalog serials for precise field identification.

5. 100% Comprehensive Factory Testing: Built under rigorous manufacturing standards where each production unit undergoes strict physical inspection, precise electrical resistance testing, and premium leak detection verifying fluid-tight integrity.

Technical Parameter Specifications

• Max. Current: 200A Single Barrel in 3.3-inch diameter layout
• Max. Voltage: 38.0 kV Nominal Voltage Class
• Interrupting Capacity: 50,000A rms Symmetrical “C” Rated Backup protection
• Application: Pad-mounted Distribution Transformers, Box-type Compact Substations, Substation Trans-Guard Enclosures, Wind/Solar Power Distribution Switchgear.
• Key Materials: Filament-Wound Fiberglass Cylinder Tube, Compacted Silica Sand, Solid Copper Contact Caps, Heavy-duty Fluid-tight Gaskets. Manufactured and compliant with industry standard IEEE C37.40 specifications.