Reliable power for Canada's overhead networks - CSA-compliant and outdoor-ready
01 General
1.1 Project Description
To meet the demands of local utility distribution in Canada, three units of 50 kVA, 13.8 kV single-phase pole-mounted transformers were delivered. Designed and built in compliance with CSA C2.1 and C802.1 standards, these transformers ensure reliable performance and full adherence to Canadian electrical requirements.
Each transformer electric pole features a primary voltage of 13.8 kV Delta and secondary voltage of 347 V, with a BIL rating of 95 kV/30 kV, impedance of 2.3% ±15%, average winding temperature rise of 65 °C, and additive polarity. Designed for outdoor ONAN cooling, the units include a 5-position tap changer (±2×2.5%) and are equipped with cover-mounted high-voltage and side-mounted low-voltage bushings for standard pole-top installation.
As a typical transformer electric pole solution, these units are engineered for overhead power distribution in outdoor environments and are ideal for:
• Residential areas in suburban or rural regions
• Light commercial loads with single-phase supply
• Network expansion or feeder reinforcement at 13.8 kV
1.2 Technical Specification
50kVA single phase electric pole mounted transformer specification and data sheet
| Delivered to | Canada |
| Year | 2025 |
| Type | Single phase pole mounted transformer |
| Standard | CSA C2.1 |
| Rated Power | 50KVA |
| Frequency | 60HZ |
| Polarity | Subtractive |
| Vector group | Ii0 |
| Primary Voltage | 13800V |
| Secondary Voltage | 347V |
| Winding Material | COPPER |
| Impedance | 2.3% |
| Cooling Method | ONAN |
| Tap Changer | NLTC |
| Tapping Range | ±2X2.5% |
| Efficiency | 98.84 % |
| No Load Loss | 135W |
| On Load Loss | 705W |
| Accessories | Standard Configuration |
1.3 Drawings
50kVA single phase electric pole mounted transformer dimensions and weight details
02 Manufacturing
2.1 Core
| This 50kVA electric pole mounted transformer features a high-quality cold-rolled silicon steel core formed by winding. Its compact structure and uniform magnetic circuit effectively reduce no-load loss to 160W. Designed to meet CSA C2.1 standards, it is well-suited for 13.8/0.347kV distribution applications. |  |
2.2 Winding
The transformer winding uses copper material, with the low-voltage winding formed by wire winding and the high-voltage winding made from foil winding. This combination ensures excellent electrical conductivity and efficient heat dissipation. The subtractive polarity and Ii0 vector group are precisely engineered by skilled technicians to optimize performance and reliability, meeting strict manufacturing standards.
2.3 Tank
| The transformer tank is made of durable mild steel and coated with light grey epoxy paint to enhance corrosion resistance. Designed as a sealed structure, it effectively prevents oil leakage and moisture intrusion. Each unit undergoes strict air-tightness testing to ensure excellent sealing performance, providing reliable protection for internal components in harsh outdoor environments |  |
2.4 Final Assembly
 | During assembly, HV bushings are mounted on the tank top, with the H1 terminal using a 4-way clamp and H2 connected internally by bolts. LV spade terminals are installed on the tank side for easy wiring. Core grounding, tank grounding, and grounding straps are installed, with a stainless steel one-hole spade grounding terminal ensuring safe and reliable operation. |
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 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 | 0.05~0.08 | Pass |
| 3 | Polarity tests | / | Additive | Additive | Pass |
| 4 | No-load losses and excitation current | % | I0 :: provide measured value(100%) | 0.24 | Pass |
| kW | P0: provide measured value(100%) | 0.1089 | |||
| % | I0 :: provide measured value(105%) | 0.27 | |||
| kW | P0: provide measured value(105%) | 0.123 | |||
| / | the tolerance for no load loss is +15% | / | |||
| 5 | Load losses , impedance voltage,total losses and efficiency | / | t:85℃ the tolerance for impedance is ±15% the tolerance for total load loss is +8% | / | Pass |
| % | Z%: measured value | 2.27 | |||
| kW | Pk: measured value | 0.636 | |||
| kW | Pt: measured value | 0.7449 | |||
| % | Efficiency not less than 98.84% | 99.00 | |||
| 6 | Applied Voltage Test | / | LV: 10kV 60s HV：34kV 60s | No collapse of the test voltage occurs | Pass |
| 7 | Induced Voltage Withstand Test | / | Applied voltage (KV):0.694 | No collapse of the test voltage occurs | Pass |
| Duration(s):40 | |||||
| Frequency (HZ): 180 | |||||
| 8 | Insulation Resistance Measurement | GΩ | HV-LV·to·Ground | 26.3 | Pass |
| LV-HV to Ground | 32.2 | ||||
| HV&LV to Ground | 28.7 | ||||
| 9 | Leakage Test | / | Applied pressure：20kPA | No leakage and no Damage | Pass |
| Duration：12h | |||||
| 10 | Oil Test | kV | Dielectric Strength | 60.9 | Pass |
| mg/kg | Moisture Content | 10.5 | |||
| % | Dissipation Factor | 0.138 | |||
| mg/kg | Furan Analysis | ≤0.1 | |||
| / | Gas Chromatography Analysis | / |
04 Site And Summary
This transformer for electric pole applications is a 50 kVA single-phase pole-mounted unit specifically designed for local distribution systems in Canada, meeting major North American power standards. It is ideal for outdoor overhead power supply scenarios at 13.8 kV, particularly suited for suburban residential areas, small commercial facilities, and grid expansion projects that require safe, reliable, and low-maintenance power equipment.
With strong structural integrity and stable performance, the transformer electric pole is built to withstand harsh weather and environmental conditions. It features excellent sealing and cooling capabilities, along with a high-efficiency, energy-saving design to meet Canada’s strict requirements for energy conservation and reliability. Its user-friendly installation and long-term durability make it an optimal choice for utility companies and infrastructure development projects involving electric pole-mounted transformers.
