100 KVA Powerline Transformer-7.2/0.12*0.24 KV | Canada 2025

Seamless energy delivered by our single phase pad mounted transformer.

01 General

1.1 Project Description

100 kVA three phase pad mounted transformer was delivered to Canada in 2025. The rated power of the transformer is 100 kVA with KNAN cooling. The high voltage is 12.47GRDY/7.2 kV with ±2*2.5% tapping range (NLTC), the low voltage is 0.24/0.12 kV, they formed a vector group of Ii6.

A single-phase pad-mounted transformer is a compact, ground-level electrical distribution device designed to step down utility voltage to levels suitable for residential and light commercial use. Encased in a locked, tamper-resistant metal cabinet, it is typically installed on a concrete pad at street level or on private property, offering a safe and aesthetically discreet alternative to pole-mounted units. These transformers are integral to the final stage of the power distribution network, reliably delivering electricity to neighborhoods, shopping centers, and individual buildings.

Key design features prioritize safety, durability, and low maintenance. The sealed enclosure protects internal components-including the core, windings, and insulation fluid (typically mineral oil or biodegradable ester)-from weather, contamination, and unauthorized access. Equipped with fused cutouts and load-break bushings, they facilitate safe operation and easy servicing by utility personnel.

Their primary advantages include enhanced public safety, reduced visual impact, and easier accessibility for maintenance compared to overhead systems. As essential nodes in underground electrical distribution, single-phase pad-mounted transformers provide the critical interface between the medium-voltage grid and the low-voltage circuits that power everyday life, ensuring a reliable and continuous supply of electricity to end-user.

1.2 Technical Specification

100 kVA pad mounted transformer specifications type and data sheet

1.3 Drawings

100 kVA pole mounted transformer diagram drawing and size.

02 Manufacturing

2.1 Core

The wound core is manufactured by precision-wrapping continuous, high-quality grain-oriented silicon steel strips into an annular or rectangular-annular structure without overlapping seams or air gaps; this design minimizes magnetic resistance, reduces no-load loss and excitation current significantly, enhances the transformer’s energy efficiency, and ensures stable magnetic flux distribution, while its compact configuration contributes to the overall small footprint of the pad-mounted unit, making it ideal for outdoor installation scenarios with limited space.

2.2 High-Voltage Bushing

The high-voltage bushing is a critical plug-in (or plug-in-type) interface. It is designed as a self-contained, separable component that securely inserts into a matching receptacle on the transformer tank. This bushing provides the insulated electrical connection from the internal transformer windings to the external underground medium-voltage cable. Its primary advantages are enhanced safety and operational flexibility: it incorporates a load-break elbow connector, allowing the circuit to be safely de-energized and isolated for maintenance or switching without disrupting the entire feeder. The design features a robust elastomeric interface that ensures a reliable, waterproof, and submersible seal, protecting the transformer from moisture and contamination. This plug-and-play design significantly improves serviceability, enabling quick and safe connection or disconnection by utility crews, which is essential for the efficient operation of underground distribution systems.

2.3 Two Position Load Break Switch

The integrated two-position load break switch is a key operational and safety component. It provides two distinct, operator-selectable states: “Close” to energize the transformer from the primary source, and “Open” to safely interrupt load current and provide visible isolation for maintenance. This oil-immersed switch, internally mounted and externally operated via a rotating handle, allows for the safe sectionalizing and de-energizing of the transformer directly at the pad, eliminating the need for separate external disconnecting devices.

2.4 Oil Level Gauge

The oil level gauge is a critical visual monitoring component installed on the tank, constructed from corrosion-resistant materials to withstand outdoor harsh conditions (temperature fluctuations, humidity, UV exposure). It features clear graduated markings and high/low oil level indicators, enabling on-site personnel to quickly verify the insulation oil level-essential for maintaining effective heat dissipation and electrical insulation. Its intuitive design facilitates timely detection of oil leakage or insufficient oil, preventing transformer overheating and potential failures, thus ensuring reliable operation in distribution networks.

2.5 LV Bushing

The LV bushing of the single-phase pad-mounted transformer is a critical insulating and conductive component, rated for 1.2kV voltage (30kV BIL) and 630A current, constructed with a C11000 copper conductor and an epoxy resin-curing agent system, designed to fit a 47.0±0.5mm (46.5±0.5mm reference) transformer tank opening. It features a Ф63×5 O-ring gasket for effective sealing, tin-plated 7-hole terminals and nuts paired with an unplated copper conductive rod, operates within a -40°C to 130°C temperature range, and is suitable for indoor use free from salt spray and chemical corrosion, reliably transmitting low-voltage power while ensuring insulation performance and structural compatibility with the pad-mounted unit.

2.6 Bayonet Fuse

The Bay-O-Net fuse for single-phase pad-mounted transformers, part of Eaton’s Cooper Power™ series, is available in 23 kV (sidewall/cover-mounted) and 38 kV (sidewall-mounted) ratings, designed for use with transformers filled with Envirotemp™ FR3™ fluid, transformer oil, or approved equivalents. It features hotstick operability and deadfront construction for safety, with optional flapper valves (sidewall-mounted only) to minimize oil spillage during fuse replacement, silver-plated terminals (standard for 38 kV, recommended for high-ampere applications) for reliable connections, gas ports to prevent excess pressure and restrike, and robust sealing; it supports loadbreak operation, requires series connection with an isolation link or current-limiting fuse, and protects the transformer and distribution system by interrupting faults while enabling easy inspection and replacement of fuse elements.

03 Testing

The testing of the single-phase pad-mounted transformer (e.g., 100kVA, 7.2-0.24/0.12kV) adheres to CSA C227.4-21 and CSA-C802.1-13 (R2018) standards, encompassing routine tests such as winding resistance measurement, ratio and phase-relation tests, no-load/load loss and impedance voltage determination, applied/induced voltage withstand tests, 20kPa/12h pressure leak testing, insulation resistance measurement, and oil dielectric testing (including dielectric strength, moisture content, and furan analysis); these tests verify key performance metrics (e.g., ≤0.28kW no-load loss, ≥98.99% efficiency, 2.1% impedance), ensure insulation integrity, structural tightness, and compliance with rated parameters, confirming reliable and safe operation under specified conditions.

04 Packing and Shipping

05 Site And Summary

Combining robust design, exceptional efficiency, and reliable performance, our single-phase pad-mounted transformer stands as a trusted solution for modern distribution networks-whether powering commercial facilities, industrial sites, or residential areas with limited space. Engineered with high-quality components (including low-loss wound cores, durable LV bushings, intuitive oil level gauges, and safety-focused Bay-O-Net fuses) and validated through rigorous testing to meet global standards, it delivers stable voltage transformation, excellent heat dissipation (ONAN cooling), and long-term durability in outdoor environments. With its compact footprint, easy maintenance, and compliance with safety and efficiency regulations, this transformer not only minimizes operational costs but also ensures uninterrupted power supply for critical applications. Choose our single-phase pad-mounted transformer for a seamless blend of performance, safety, and value-backed by our commitment to quality and responsive support.