American Box Transformer/Pad Mount transformer

Equipment Display

Overview

The American-style pad-mounted transformer is a type of transformer that combines high-voltage load switches, plug-in fuses, backup protection fuses, the transformer body, and no-load switches within a sealed oil tank, using transformer oil as the insulating medium. The high-voltage circuit and transformer body are assembled inside the oil tank, with high-voltage circuit input and operations conducted on the high-voltage side. The low-voltage circuit typically consists of low-voltage circuit breakers, current transformers, and metering instruments, installed in the low-voltage compartment.

Use Environment

1. Altitude
   ≤1000m
2. Wind speed
   Equivalent to 34m/s (not more than 700Pa)
3. Temperature
   Daily relative temperature average value <95%; monthly relative temperature average value <95%
4. Shockproof
   Horizontal acceleration is not more than 0.4m/5, vertical acceleration is not more than 0.15m/s
5. Installation site inclination
   Not more than 3 degrees

Installation Environment

The surrounding air is not polluted by corrosive, flammable gases and other obvious pollutants, and there is no severe vibration at the installation site. When ordering this product beyond the above conditions, you can negotiate technical parameters with our company

Composition

High-Voltage System and Output Methods

The high-voltage system wiring methods include ring network type, terminal type, and terminal dual-circuit type. The ring network type features “one input, two outputs”: one power input, one output from the transformer’s low-voltage side, and another leading to another transformer or electrical device, providing power to the low-voltage side of another transformer or other equipment. The terminal type features “one input, one output”: one power input and one output from the transformer’s low-voltage side. The terminal dual-circuit type features “one input, one output, one backup”: one power input, one output from the transformer’s low-voltage side, and one backup power supply, which provides power in case of a main power supply failure.

Elbow Bushing (Elbow Cable Plug)

The high-voltage input of the combination transformer is achieved through underground cables using elbow-type cable heads, which consist of three parts: the elbow connector, load socket, and bushing sleeve. The elbow connector comes in single-pass and double-pass types. The single-pass type connects directly to the cable and the high-voltage grid, while the double-pass type connects one end to a lightning arrester and the other to a voltage source.

Lightning Arrester

The lightning arrester primarily serves as protection against lightning strikes and comes in internal and external types. The internal type is placed inside the oil tank at the high-voltage output for protection.

Other Components

No-load switches, oil level gauges, pressure gauges, temperature gauges, pressure relief valves, and other components. Additional components such as low-voltage air circuit breakers, secondary-side metering, and compensation devices can be installed as needed. The transformer’s fuses, multi-position ring network load switches, and no-load tap changers are installed as components inside the oil tank, allowing easy replacement of fuses or operation of load switches to change the transformer’s operating conditions. The high-voltage side is powered by load-break elbow-type cables, and the low-voltage output compartment is installed outside the tank, with space for additional protective devices and instruments as required. All live parts are enclosed within the oil tank, with no exposed live components.

Protection System

The American-style pad-mounted transformer protection system uses high-voltage current-limiting fuses and overload protection fuses in series for high-voltage protection, and low-voltage air circuit breakers for overload and short-circuit protection in the low-voltage circuit. The plug-in fuse (overload protection fuse) has excellent tolerance to transformer surges and is primarily used to protect the transformer during overloads and low-voltage short circuits. The backup protection fuse (high-voltage current-limiting fuse) can safely interrupt all expected currents that could cause melting and is mainly used to protect the transformer and distribution system during internal faults.

Standards Referenced

IEC 60076: General requirements for power transformers
IEC 61330: Safety standard for high/low voltage prefabricated substations
IEEE C57.: General requirements covering the safety and performance of liquid-immersed distribution, power and regulator transformers.

Standard : IEC60076/IEC 61330/IEEE C57.
Warranty: 2 Years

Key Features

1. The transformer adopts non-quality alloy transformer, which has good harmonic resistance, high overload capacity, low loss, low noise, low temperature rise, long service life and other advantages.
2. The shell of Taobian adopts high-quality cold-rolled steel plate, which has strong mechanical strength such as bending resistance, impact resistance and tensile resistance. The surface is treated with electrostatic powder spraying and has good anti-corrosion performance.
3. The high voltage circuit is protected by double fuses, of which the plug-in fuse is a dual-sensitive fuse (potential, current), and the backup fuse is a current-limiting fuse, which reduces the operating cost;
4. The high voltage incoming line adopts an electric maintenance connector structure, which is fully insulated, safe and reliable, and easy to operate:
5. It can be used for both ring networks and terminals, and the conversion is very convenient, which improves the reliability of power supply
6. The structure is compact, small in size, easy to install and flexible;
7. Fully insulated, fully sealed structure, safe and reliable, maintenance-free, and reliable protection of personal safety

Product workshop real shot

Package & delivery :

Package :  seaworth wooden box case

Poart : Shanghai / Shenzhen/ Qingdao/ Tianjin port,China etc

Singel pacakge size: According capacity

Singe package weight: According capacity

Technical parameter: