High Voltage Transformer Bushing
01
ANSI 18KV Transformer Bushing
Video
Key Features and Characteristics
Rated Voltage
18kV, indicating the maximum voltage the bushing is designed to handle during continuous operation.
Basic Impulse Level (BIL)
Often specified (e.g., 150kV), this indicates the bushing's ability to withstand high-voltage surges caused by lightning or switching operations.
Rated Current
The continuous current-carrying capacity (e.g., 50A, 65A).
Standard
Complies with ANSI (American National Standards Institute) standards, ensuring interchangeability and performance criteria are met for the North American market.
Insulation Material
Typically made of high-strength porcelain, known for its excellent electrical insulation properties, durability, and resistance to environmental factors like moisture and pollution. Some may use oil-impregnated paper (OIP) or other materials for insulation.
Construction
Can be either a solid type (often porcelain) for lower to medium voltages or a condenser type for higher voltages, employing layers of insulation and conductive materials to evenly distribute electrical stress.
Mounting
Designed to be mounted through an opening in the transformer tank, with features like flanges and gaskets to create a secure and oil-tight seal.
Conductor Connection
Includes a conductive rod or tube through which the electrical conductor passes. The external connection can vary (e.g., eye bolt, terminal flag, threaded stud).
Glaze Color
Often light gray for porcelain bushings.
Accessories
May include gaskets (NBR), hardware (bolts, nuts, washers made of materials like copper, brass, or stainless steel), and flexible wire connectors.
Functions of a Transformer Bushing
Electrical Insulation
Prevents the high-voltage conductor from coming into contact with the grounded transformer tank, ensuring safe and reliable power transmission.
Conduction
Provides a path for electrical current to flow into or out of the transformer windings.
Mechanical Support
Securely holds the conductor in place as it passes through the transformer wall.
Sealing
Prevents oil leakage from the transformer tank and ingress of moisture or contaminants, maintaining the integrity of the insulation system.