A reliable transformer on power pole delivering efficient and stable energy for modern communities
01 General
1.1 Project Description
This 50 kVA single-phase pole-mounted distribution transformer strictly adhere to IEEE C57.12.20 standards. It is widely used in North American distribution networks, typically installed in 13.8 kV grounded-wye systems, where the transformer is connected phase-to-neutral at 7.97 kV and provides a reliable 120/240 V split-phase output for residential and light commercial applications.
The 50 kVA transformer on power pole adopts an amorphous metal core, which greatly reduces no-load loss to only 0.043 kW. It gives very good energy-saving performance even at light load. With a rated impedance of 2.1%, the transformer offers good voltage regulation and, together with its ±2×2.5% no-load tap changer, ensures stable secondary voltage within ±5% of nominal.
Its design features include ONAN natural cooling, aluminum windings, and additive polarity, with vector group Ii6. These features make the transformer compact. It is efficient and reliable for pole-mounted use. The unit has a surge arrester boss. This makes it easy to add protective devices.
The transformer has low losses. It works with high efficiency. It also adapts well to different needs. This makes it a good choice for modern power distribution systems.
1.2 Technical Specification
50kVA Single phase pole mounted transformer specification and data sheet
| Delivered to | Canada |
| Year | 2024 |
| Type | Single phase pole mounted transformer |
| Standard | IEEE C57.12.20 |
| Rated Power | 50KVA |
| Frequency | 60HZ |
| Polarity | Additive |
| Vector group | Ii6 |
| Primary Voltage | 7.97/13.8Y kV |
| Secondary Voltage | 120/240V |
| Winding Material | Aluminum |
| Impedance | 2.1% |
| Cooling Method | ONAN |
| Tap Changer | NLTC |
| Tapping Range | ±2X2.5% |
| No Load Loss | 0.043 KW |
| On Load Loss | 0.5 KW |
| Accessories | Surge arrester boss |
1.3 Drawings
50kVA transformer on power pole drawing and nameplate
02 Manufacturing
2.1 Core
| The pole-mounted transformer features an amorphous metal core, made from a melt of iron, boron, silicon, nickel, and carbon. Compared to conventional cold-rolled silicon steel, this core is isotropic, extremely thin (0.03 mm), and has high electrical resistivity, significantly reducing eddy current losses. It achieves remarkably low no-load loss (0.043 kW) and load loss (0.5 kW), offering high efficiency, simplified manufacturing, and eco-friendly operation. |  |
2.2 Winding
 | Our single-phase pole-mounted transformers feature low-voltage foil coils and high-voltage wire coils. Customers choosing aluminum LV coils benefit from reduced weight and cost, while maintaining comparable reliability and operating life to copper. High-voltage wire coils ensure insulation and voltage balance. |
2.3 Tank
| This single-phase cylindrical fuel tank is constructed from mild steel, with the cover and bottom formed using a thin-sheet drawing process. Equipped with two HV bushings on the cover and three LV eyebolt bushings on the sidewall, its fully sealed design ensures superior leak resistance and operational reliability. |  |
2.4 Final Assembly
 | How to install the coil and wound core: First, lay the first C-core flat (opening facing up like a “U”). Take the coil and fully sleeve its central hole onto one leg of the core, pushing it down to the bottom. Take the second C-core, align its cut precisely with the first core’s cut. Gently close it until the two parts fully mate. Install the top and bottom clamping plates, insert the long screws. |
03 Testing
Routine Test
- Resistance Measurements
- Ratio Tests
- Polarity Test
- No Load Losses and No Load Current
- Load Losses and Impedance Voltage
- Applied Voltage Test
- Induced Voltage Withstand Test
- Insulation Resistance Measurement
- Leak Testing with Pressure for Liquid Immersed Transformers
- Oil Dielectric Test
Test Results
| No. | Test Item | Unit | Acceptance Values | Measured Values | Conclusion |
| 1 | Resistance Measurements | % | / | / | Pass
|
| 2 | Ratio Tests | % | The deviation of voltage ratio on the principal tapping: ≤0.5% Connection symbol: Ii6 | 0.02 | Pass
|
| 3 | phase-relation tests | / | Additive | Additive | Pass
|
| 4 | No-load losses and excitation current
| % kW | t:85℃ I0 :: provide measured value P0: provide measured value the tolerance for no load loss is +10% | 1.11(100%) 2.16(105%) 0.045(100%) 0.061(105%) | Pass
|
| 5 | Load losses impedance voltage and efficiency
| % kW kW | t:85℃ Z%: measured value Pk: measured value Pt: measured value the tolerance for impedance is ±10% the tolerance for total load loss is +6% | 2.21 0.496 0.543 99.37 | Pass
|
| 6 | Applied Voltage Test | kV | HV: 34kV 60s LV：10kV 60s | No collapse of the test voltage occurs | Pass
|
| 7 | Induced Voltage Withstand Test | kV | Applied voltage (KV): 15.94 Duration(s):40 Frequency (HZ): 150 | No collapse of the test voltage occurs | Pass
|
| 8 | Leakage Test | kPa | Applied pressure：20kPA Duration：12h | No leakage and no Damage | Pass
|
| 9 | Insulation Resistance Measurement | GΩ | HV&LV to Ground: | 120.0 | / |
| HV-LV to Ground | 51.8 | ||||
| LV-HV to Ground | 62.6 | ||||
| 10 | Oil Dielectric Test | kV | ≥45 | 55.48 | Pass
|
| 11 | Lightning impulse test | kV | full wave, Half wave | No collapse of the test voltage occurs | Pass
|
04 Packing and Shipping
05 Site and Summary
This 50 kVA single-phase pole-mounted transformer is made for Canada in 2024. It follows IEEE C57.12.20. It works on 13.8 kV grounded-wye systems, giving 120/240 V for houses and small businesses.
The transformer has an amorphous metal core. It keeps no-load loss at 0.043 kW and load loss at 0.5 kW. It saves energy and runs with high efficiency. Aluminum windings, ONAN cooling, and additive polarity make the unit compact, safe, and reliable. The surge arrester boss allows easy protection upgrades.
This transformer on power pole combines efficiency, reliability, and eco-friendly performance, making it a strong choice for modern distribution networks.
Scotech makes quality transformers for global customers. Our products save energy, cut losses, and give stable power. We deliver safe and proven solutions that help power grids work better every day.
Scotech – reliable transformers, efficient power, better networks.
