This ANSI standard low-voltage transformer bushing is composed of four major assemblies: top terminal assembly, porcelain insulating main body, sealing & fixing assembly, bottom conductive terminal, with two optional terminal configurations:
Top Conductive Terminal (Two Optional Types)
Type 1 (Eyebolt Swivel Type): Universal spherical connector, lock hex nut, external threaded conductive stud. The spherical joint supports multi-angle cable connection to match internal wiring layout of American pad-mounted transformer. The hex nut fastens the busbar tightly, and the threaded stud runs through the porcelain insulator for current conduction.
Type 2 (Flat Lug Terminal Type): Hot-dip galvanized steel two-hole mounting plate with integrated snap buckle. Two mounting holes are used for bolt connection with copper busbar. The buckle design clips onto the top conductor of porcelain bushing directly for fast installation, ideal for hard copper bar side mounting on transformer tank.
Main Porcelain Insulator Body
Integral high-temperature fired electrical porcelain, divided into three sections: upper rain shed section, middle positioning shoulder, lower tank insertion insulating column. Glossy glazed surface resists transformer oil contamination, UV degradation and condensation. As the key insulation component, it isolates live conductor from transformer tank to avoid earth short circuit.
Tank Sealing & Fastening Kit
Consists of black metal retaining flange, oil-resistant rubber gasket and lock washer. The flange locks onto the porcelain shoulder, compressing the rubber gasket against tank opening to prevent insulating oil leakage and fix the bushing against rotation. The rubber seal is formulated for long-term immersion in mineral transformer oil with outstanding anti-aging performance.
Bottom Outlet Conductive Assembly
Brass through stud, multi-layer lock nuts, copper transition washer. The through stud delivers continuous current between top and bottom terminals. Stacked nuts firmly fasten external cables and cable lugs. Copper washers reduce contact resistance to avoid overheating and thread ablation under rated load current.

Core Advantage

Full ANSI Standard Compliance for American-Style Distribution Transformers
Manufactured in accordance with ANSI/IEEE C57.19.00 transformer bushing standard, rated voltage 1.2kV with rated current range 125A~250A for low-voltage secondary side of pad-mounted transformers and American oil-immersed distribution transformers. Direct replacement for OEM original bushings with fully compatible dimension, mounting size and current load capacity. No rework required for transformer export or field maintenance, perfectly applicable for North America, South America and other regions adopting ANSI power standards.

Dual Terminal Options for Two Field Wiring Conditions
The eyebolt swivel terminal works for flexible cable connection, allowing arbitrary wiring angle to release cable bending stress and prevent wire breakage. The flat lug terminal is optimized for rigid copper busbar connection to improve assembly efficiency for centralized busbar wiring on cabinet and substation equipment. Both terminals share identical porcelain insulator and sealing parts for interchangeability, cutting customers’ spare parts inventory cost by half.
Robust Porcelain Insulation & Full Sealing for Long Service Life in Oil-Immersed Outdoor Operation
Solid electrical porcelain features strong bending and impact resistance to avoid crack during transportation and assembly. The glazed surface is hydrophobic and anti-fouling to prevent pollution flashover under rain, dust and coastal salt fog. Double-layer rubber sealing at tank flange accommodates thermal expansion & contraction of transformer oil, effectively stopping oil leakage and cutting long-term maintenance cost of transformers.
Modular Structure for Fast On-Site Installation
Pre-assembled integrated module without on-site assembly of insulation and sealing components. Insert the whole bushing into transformer tank opening and fasten bottom nuts to complete installation and sealing. Single-person operation is available to shorten transformer overhaul and production assembly time significantly.