500 KVA Ground Mounted Transformer-12.47/0.48 KV

500 kva 12.47 kv to 0.48 kv pad mounted transformer radial type left front

Utility-Grade Reliability for EV Charging and Mixed-Use Projects.

01 General

1.1 Project Description

These two 500 kVA three-phase ground mounted transformers were supplied to the American market in 2025, designed and manufactured in accordance with IEEE Std C57.12.34-2022. Intended for outdoor medium-voltage distribution, the units operate at 12.47 kV on the primary side and 480 V on the secondary, supporting stable power delivery for a wide range of commercial and light industrial applications across North America.

A dead-front, radial-feed pad-mounted design is used-standard practice for public-access installations where safety comes first. The transformers are well suited for commercial complexes, logistics centers, data facilities, manufacturing sites, and municipal infrastructure, particularly in locations where space is limited and power quality cannot be compromised.

As 500 kVA ground mounted transformers, the focus is on practical performance rather than unnecessary complexity. High efficiency, long service life, and reduced maintenance requirements make these units a good fit for both utility-owned and customer-owned distribution networks, whether installed in urban centers, suburban developments, or industrial areas.

1.2 Technical Specification

500kVA three phase pad mounted transformer specification and data sheet

Delivered to	America
Year	2025
Type	Three phase pad mount transformer
Standard	IEEE Std C57.12.34-2022
Rated Power	500KVA
Frequency	60HZ
Feed	Radial
Front	Dead
Phase	three
Cooling Type	KNAN
Liquid insulant	FR3 Oil
Primary Voltage	12.47 kV
Secondary Voltage	0.48 kV
Vector Group	Dyn1
Winding Material	Copper
Impedance	5.75%
K factor	K4
BIL	95AC34
Efficiency and Losses Standard	99.35% DOE 2016
Tap Changer	NLTC
Tapping Range	±2*2.5%
No Load Loss	2.4 kV
On Load Loss	15.79 kV
Accessories	Standard Configuration

1.3 Drawings

500kVA three phase pad mounted transformer drawing and nameplate

500 kva 12.47 kv to 0.48 kv pad mounted transformer radial type drawing

500 kva 12.47 kv to 0.48 kv pad mounted transformer radial type nameplate

02 Electrical Design and Winding Features

2.1 K4 Harmonic-Rated Design

The transformer incorporates a K4 harmonic-rated design to accommodate the increasing use of non-linear loads in modern electrical networks. Equipment such as variable frequency drives, UPS systems, rectifiers, and other power electronic devices can introduce harmonic currents that place additional thermal stress on standard transformers.

By addressing these conditions in the core and winding design, the K4 rating helps control temperature rise and limits accelerated insulation aging. In day-to-day operation, this translates into more stable performance under mixed loading conditions and improved reliability for commercial and light industrial power distribution systems.

2.2 Electrostatic Shielding

500 kva 12.47 kv to 0.48 kv pad mounted transformer radial type transformer winding

500 kva 12.47 kv to 0.48 kv pad mounted transformer radial type iron core

Electrostatic shielding is installed between the high-voltage and low-voltage windings, and also between the windings and the core. The purpose is straightforward-control stray currents, limit internal electrical noise, and keep unwanted coupling to a minimum. With insulation coordination improved and electromagnetic interference reduced, the transformer becomes a better source for sensitive downstream loads. In real applications, that translates to cleaner power and fewer disturbances, especially in facilities with a high concentration of electronic equipment.

2.3 Outdoor Protection and Enclosure

500 kva 12.47 kv to 0.48 kv pad mounted transformer radial type tank enclosure

For outdoor service, the transformer tank and enclosure are finished with a C5M-grade anti-corrosion coating, providing long-term resistance to moisture, salt spray, and UV exposure. This makes the unit suitable for coastal areas, industrial zones, and other demanding environments.

The transformer is also fitted with a tamper-proof control cabinet rated to NEMA 3R. Unauthorized access is effectively restricted, while the enclosure remains fully capable of withstanding rain and snow. The combination supports compliance with North American installation practices and helps reduce maintenance over the equipment’s lifecycle.

03 Performance, Safety and Accessibility

3.1 Additional Performance and Safety Advantages

Protection devices for 500 kVA, 12.47 kV to 0.48 kV radial‑type pad‑mounted transformer

The transformer incorporates copper windings for superior conductivity, enhanced efficiency, and improved thermal performance. It uses FR3 natural ester insulating oil, providing a high fire point, excellent moisture tolerance, and environmentally friendly characteristics. A Critical monitoring and safety accessories include Schrader Valve, 50 SSFM Pressure Relief Valve, Liquid Level Gauge with Alarm Contact (25° level), Dial-Type Thermometer with Alarm Contacts, and Pressure Vacuum Gauge with Alarm Contacts, enabling precise supervision and early fault detection.

3.2 Man Hole 20" With Padlock

500 kva 12.47 kv to 0.48 kv pad mounted transformer man hole

The transformer tank features a 20″ manhole with a padlock, providing easy access for internal inspection, maintenance, and oil sampling-enhancing operational safety and convenience.

3.3 Finally Assembly

The final assembly stage is not only the process of putting all the components together into a finished product, but also a critical phase for ensuring product quality and performance. In the three-phase ground mounted transformer assembly process, we consistently adhere to standardized, normative, and traceable workflows, from filling the oil tank to the precise installation of internal components and the configuration of external monitoring devices, ensuring that each installation step meets the design requirements

500 KVA pad mount transformer active part lifted — Active Part Lifted

500 KVA pad mount transformer active part lowered into tank — Active Part Lowered into Tank

500 kva, 12.47 kv to 0.48 kv radial‑type pad‑mounted transformer oil tank inside — Internal Components Installed

500 kva, 12.47 kv to 0.48 kv radial‑type pad‑mounted transformer oil filling — Filling with Insulating Oil

500 kva, 12.47 kv to 0.48 kv radial‑type pad‑mounted transformer oil — Oil Tank Filled

500 kva 12.47 kv to 0.48 kv pad mounted transformer external accessories installed — External Accessories Installed

04 Testing

Oil Tank Vacuum Deformation Test

Test Requirements

1. Measurement Reference Points
Ten reference points shall be set at locations on the oil tank wall, cover, reinforcements, edges, etc., where maximum vacuum-induced bending is expected.
The specific positions are indicated in the diagram below.
Measure and record the distance from each reference point to the oil tank wall.
2. Vacuum Application
Apply a vacuum of -67 kPa to the oil tank.
3. Post-Test Inspection
After releasing the vacuum, measure the deformation at each reference point.
Carefully inspect the oil tank for any signs of damage, cracks, or permanent deformation.

Test Result: Passed

500 KVA Ground Mounted Transformer Test Result -1