Efficient, reliable, and eco-friendly—powering your distribution network with Scotech’s 50 kVA pole-mounted transformer
01 General
1.1 Project Description
These 75 kVA single-phase pole mounted transformers manufactured by Scotech. Pole-mounted transformers step down high-voltage electricity to levels suitable for households and small businesses, ensuring a stable power supply in urban and rural areas. These transformers are exported to Canada, fully complying with IEEE C57.12.20 standards and meeting modern utility requirements for energy efficiency.
The order includes 8 units of the 75 kVA transformer. Each unit is designed for a high voltage of 7.97/13.8Y kV and a low voltage of 120/240 V split-phase. Equipped with two high voltage bushings and three low voltage bushings, the transformer ensures reliable service for residential and light commercial applications.
The transformer provides four tapping positions on the high voltage side with a range of ±2 × 2.5%, giving utilities flexibility to adjust voltage according to line conditions.
With a rated impedance of 2.1%, a no-load loss of 0.148 kW, and a load loss of 0.675 kW, it demonstrates high efficiency and low operating losses. It adopts ONAN cooling, aluminum windings, and additive polarity, designed for compact size and easy pole-mounted installation.
The transformer is also equipped with a surge arrester boss, allowing integration of protective devices for improved safety and reliability in distribution networks.
1.2 Technical Specification
75kVA 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 | 75 kVA |
| 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 | 0.148 KW |
| On Load Loss | 0.675 KW |
| Accessories | Surge arrester boss |
1.3 Drawings
75kVA pole mounted transformer dimensions and weight details
02 Manufacturing
2.1 Core
| 75 kVA single-phase pole-mounted transformers utilize high-quality silicon steel laminations. Silicon steel is the most common material for transformer cores. It possesses magnetic properties, including high permeability and low core losses. Compared to traditional laminated cores, wound cores are lightweight, enabling the construction of more compact and lightweight transformers. |  |
2.2 Winding
 | The transformer’s windings are expertly handcrafted by veteran workers with over a decade of experience. The low-voltage winding is foil-wound, and the high-voltage winding is wire-wound, with precise control of tension to prevent foil lifting. Inter-turn and inter-layer insulation are carefully applied to avoid partial discharge. |
2.3 Tank
| The cylindrical fuel tank is made of mild steel. Thin-sheet stretching technology makes the lid and bottom lightweight and strong. The tank is fully sealed. This design makes it more adaptable to the environment and more reliable in use. It works well for outdoor uninterrupted power supply. |  |
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
- Phase-relation Test
- No Load Losses and No Load Current
- Load Losses, Impedance Voltage and Efficiency
- Applied Voltage Test
- Induced Voltage Withstand Test
- Leak Testing with Pressure for Liquid Immersed Transformers
- Insulation Resistance Measurement
- Oil Dielectric Test
- Lightning Impulse 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 | -0.03 | 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% | 0.24(100%) 0.46(105%) 0.144(100%) 0.167(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% | 2.19 0.688 0.838 99.19 | 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: | 97.1 | / |
| HV-LV to Ground | 36.1 | ||||
| LV-HV to Ground | 45.5 | ||||
| 10 | Oil Dielectric Test | kV | ≥45 | 55.50 | 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
The 75 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 and gives 120/240 V split-phase output for houses and small businesses.
The transformer has a high-quality silicon steel core. It keeps no-load loss at 0.148 kW and load loss at 0.675 kW. It runs with high efficiency and low operating cost. The windings are aluminum, with foil-wound LV coils and wire-wound HV coils. The winding work is done by skilled workers, ensuring strong insulation and safe operation.
The tank is made of mild steel. It is fully sealed, light, and strong. It gives good protection outdoors and works well in long-term service. The unit also has a surge arrester boss, which makes it easy to add protection.
SCOTECH transformers are built to international standards. Our products save energy, reduce losses, and give stable power. We supply safe and proven solutions that improve grid performance every day.
