150 KVA 3-phase Pad Mounted Transformer-34.5/0.208 KV | USA 2025

Green Grids Start on the Ground: Eco-Conscious Pad Mounted Transformers.

01 General

1.1 Project Description

150 kVA three phase pad mounted transformer was delivered to USA in 2025. The rated power of the transformer is 150 kVA with ONAN cooling. The high voltage is 34.5D kV with ±2*2.5% tapping range (NLTC), the low voltage is 0.208Y/0.12 kV, they formed a vector group of Dyn1.

Pad-mounted transformers are purpose-built outdoor distribution transformers, designed to be installed at ground level on reinforced concrete foundations. As a critical component of underground power distribution infrastructure, they reliably serve a wide spectrum of scenarios, from residential neighborhoods and commercial districts to industrial parks.

Unlike pole-mounted transformers, their low-profile, enclosure-integrated design not only blends more discreetly into urban and suburban landscapes but also places a premium on safety and maintainability. Housed in rugged, tamper-proof casings, these transformers are offered in two primary configurations: dead-front and live-front. The dead-front variant, widely favored in public areas, encases all high-voltage components within sealed, insulated covers. This design eliminates direct access to live electrical parts, drastically reducing the risk of electric shock for maintenance personnel and the public. Additionally, the sealed enclosure blocks dust, moisture, and potential theft, cutting down on long-term maintenance needs and ensuring consistent, hassle-free operation.

1.2 Technical Specification

150 kVA pad mounted transformer specifications type and data sheet

1.3 Drawings

150 kVA pad mounted transformer diagram drawing and size.

02 Manufacturing

2.1 Core

SCOTECH pad – mounted transformer’s core, crafted from high – permeability grain – oriented silicon steel sheets, adopts advanced fully mitered step – lap joint technology. It features low magnetic resistance, minimal eddy current loss and reduced operational noise, with a robust clamping structure that ensures long – term stable performance in harsh outdoor settings.

2.2 Copper Ground Strap

The copper ground strap of SCOTECH pad – mounted transformer is made of high – purity electrolytic copper for superior conductivity and corrosion resistance. Precisely crimped and securely fastened to the transformer enclosure and grounding system, it rapidly diverts fault currents to the ground, effectively safeguarding the equipment from overvoltage damage and ensuring personnel safety. Its robust construction withstands harsh outdoor conditions, delivering reliable long – term grounding performance for urban distribution applications.

2.3 Creepage Distance

Creepage distance on a pad mounted transformer is the shortest path along the surface of its bushings or insulation from a live part to ground. It is intentionally lengthened with grooves or sheds to prevent electrical tracking and flashover in wet or contaminated outdoor conditions, ensuring safety and reliability.

2.4 Final Assembly

The four-hole low-voltage (LV) bushing of pad mounted transformers has a copper lead surface and horizontal installation, featuring 4-M12×50 welded studs, a Φ85×Φ55×6 sealing ring for tight sealing, and pin distance ≥35mm. It withstands 10kV frequency endurance voltage, 30kV lightning strike voltage, partial discharge ≤10 pc at 1.2kV, and 31.25kA/2s short-circuit current, with a 1250N tensile load capacity and stable operation from -35℃ to +40℃ for outdoor power distribution.

2.5 Oil Filling Valve

The oil filling valve of pad mounted transformers is installed in the low-voltage compartment, specifically designed for convenient injection and replenishment of insulating oil to maintain optimal oil levels. It features reliable sealing mechanisms to prevent oil leakage and moisture ingress, paired with weather-resistant and corrosion-resistant construction that adapts to harsh outdoor environments. User-friendly in operation, the valve enables efficient maintenance while ensuring the transformer’s insulation performance and long-term operational reliability.

03 Testing

Ratio tests for pad mounted transformers are essential performance verification procedures that measure the voltage ratio between the primary and secondary windings, typically conducted under no-load or rated load conditions with precision testing equipment. These tests aim to confirm that the actual transformation ratio matches the designed specifications, identifying any potential deviations caused by winding faults, manufacturing inconsistencies, or operational wear. By validating the accuracy of voltage conversion, ratio tests ensure the transformer delivers stable, properly regulated power to downstream systems, prevents overvoltage/undervoltage damage to connected equipment, and maintains reliable operation within urban distribution networks.

04 Packing and Shipping

05 Site And Summary

Designed to meet the demands of modern urban power distribution, our pad mounted transformer combines robust engineering, efficient performance, and uncompromising safety to deliver reliable power solutions for commercial areas, industrial facilities, and residential neighborhoods. With its compact, weather-resistant design, premium components (including high-performance cores, secure copper ground straps, and durable low-voltage bushings), and rigorous testing (such as ratio verification and insulation checks), it ensures stable operation even in harsh outdoor conditions while minimizing maintenance needs. Whether supporting grid expansion, critical infrastructure, or everyday power supply, this transformer stands as a trusted asset-optimizing energy transmission, reducing downtime, and aligning with the evolving needs of smart, sustainable distribution networks. Choose a solution that blends durability, efficiency, and peace of mind for your power distribution requirements.