Elevating Power Distribution – Smarter, Faster, Greener Pole Mounted Solutions.
01 General
1.1 Project Description
A 75 kVA single-phase pole-mounted transformer was delivered to Canada in 2025. It has ONAN cooling, a primary voltage of 13.8 kV with a ±2×2.5% no-load tap changer (NLTC), and a secondary voltage of 0.347 kV, forming a vector group of Ii6.
Pole-mounted transformers like this one are key components of electrical distribution networks. They step down high-voltage electricity to safe, usable levels for homes, small businesses, and light industrial sites. Mounted on utility poles, they deliver reliable power-even in suburban and rural areas, where underground lines are impractical.
This transformer is ideal for residential clusters, small shops, farms, and remote facilities, such as communication stations or local utility points. Seasonal peaks, like winter heating demand, and occasional storms make steady power essential. Its compact, sturdy design makes installation straightforward, while low losses and durable aluminum windings keep maintenance minimal.
With its focus on reliability, safety, and efficiency, this unit supports growing grids, strengthens local network stability, and even accommodates small-scale renewable energy integration. It’s designed to deliver dependable, safe power-year-round, across a variety of environments.
1.2 Technical Specification
75 kVA pole mounted transformer specifications type and data sheet
| Delivered to | Canada |
| Year | 2025 |
| Type | Pole mounted transformer |
| Standard | CSA C2.2-06 |
| Rated Power | 75 kVA |
| Frequency | 60HZ |
| Phase | 1 |
| Polarity | Additive |
| Cooling Type | ONAN |
| Primary Voltage | 13.8 kV |
| Secondary Voltage | 0.347 kV |
| Winding Material | Aluminum |
| Angular displacement | Ii6 |
| Impedance | 2% |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5% |
| No Load Loss | 0.060 kW |
| On Load Loss | 0.810 kW |
1.3 Drawings
75 kVA pole mounted transformer diagram drawing and size.
02 Manufacturing
2.1 Core
 | The amorphous alloy core offers ultra-low no-load loss (70% less than silicon steel) and near-zero eddy current losses. Its lightweight yet robust wound design ensures optimal magnetic performance for pole-mounted applications, delivering unmatched energy efficiency in power distribution. |
2.2 Winding
| This pole-mounted transformer employs an optimized winding design: aluminum foil for low-voltage winding (cost-effective with good heat dissipation) and copper wire for high-voltage winding (superior conductivity and durability). This hybrid configuration ensures high efficiency, thermal stability and reliable performance in distribution networks. |  |
2.3 Tank
 | The tank of a pole-mounted transformer is typically a sealed structure made of corrosion-resistant steel plates, welded into a cylindrical or rectangular shape, with its surface treated by sandblasting and coated with anti-corrosion paint to withstand harsh outdoor conditions. The tank is filled with insulating oil for cooling and insulation, designed to be compact and lightweight, the tank is securely mounted on utility poles via welded or bolted brackets. |
2.4 Final Assembly
| 1. Winding Installation: Slide the HV/LV windings onto the core, ensuring proper insulation alignment and secure mechanical fixation. 2. Electrical Connections: Connect winding leads to tap changers, bushings, and other components, verifying contact resistance. 3. Core-Coil Drying: Place the assembled active part into a drying oven for vacuum heating to remove moisture and ensure insulation integrity. 4. Tank Placement: Hoist the dried active part into the tank, then secure it with base bolts. 5. Accessory Installation: Mount pressure relief valve, OCTC, surge arrester boss, sealing all joints. 6. Oil Filling & Sealing: Vacuum-fill insulating oil to the specified level, conduct oil sampling tests, and confirm leak-tightness to complete assembly. |  |
03 Testing
| 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 | Polarity tests | / | Additive | Additive | Pass |
| 4 | No-load losses and excitation current | % | I0 :: provide measured value | 0.33 | Pass |
| kW | P0: provide measured value(85℃) | 0.048 | |||
| (105%)P0: provide measured value(85℃) | 0.058 | ||||
| / | the tolerance for no load loss is ±10% | / | |||
| 5 | Load losses , impedance voltage,total losses and efficiency | / | t:85℃ the tolerance for impedance is ±15% the tolerance for total load loss is ±6% | / | Pass |
| % | Z%: measured value | 2.03 | |||
| kW | Pk: measured value | 0.740 | |||
| kW | Pt: measured value | 0.791 | |||
| % | Efficiency not less than 98.94% | 99.42 | |||
| 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):60 | |||||
| Frequency (HZ): 120 | |||||
| 8 | Insulation Resistance Measurement | GΩ | HV-LV·to·Ground | 120 | Pass |
| LV-HV to Ground | 20.2 | ||||
| HV&LV to Ground | 20.9 | ||||
| 9 | Leakage Test | / | Applied pressure：20kPA | No leakage and no Damage | Pass |
| Duration：12h | |||||
| 10 | Oil Test | kV | Dielectric Strength | 55.7 | Pass |
| mg/kg | Moisture Content | 9.7 | |||
| % | Dissipation Factor | 0.00317 | |||
| mg/kg | Furan Analysis | 0.03 | |||
| / | Gas Chromatography Analysis | / |
04 Packing and Shipping
4.1 Packing
 | The pole-mounted transformer is securely packaged in a sturdy wooden crate designed to withstand transportation and handling. The wooden box is constructed with durable timber, featuring reinforced corners and edges for added protection. Inside, the transformer is firmly anchored using braces and cushioning materials to prevent movement and shock damage. The exterior of the crate is marked with handling instructions, weight specifications, and directional labels to ensure proper logistics. |
4.2 Shipping
| This pole-mounted transformer will be securely packed in a customized wooden crate with shock-proof and moisture-resistant packaging, then loaded onto a truck using forklifts for delivery to the port. It will be shipped in a 40ft standard container (humidity-controlled with desiccants) under CIF terms to the Port of Montreal. Upon arrival, the crate can be unloaded using container forklifts or cranes. Full marine insurance (110% invoice value, All Risks) covers the entire shipment until 14 days post-arrival. |  |
05 Advantages & Disadvantages Of Pole-Mounted Transformers
Pole-mounted transformers are popular. Why? Long service life, easy installation, and they just work. Here’s what makes them stand out:
Versatile Applications: Homes, small commercial buildings, even remote areas-these transformers handle it all.
Flexible Power Supply: Single-phase output is standard. Need more power? Combine them into three-phase. Simple.
Cost-Effective: Cheaper than other oil-immersed transformers, yet performance stays solid.
Space-Saving: Small, lightweight, perched on a pole-no ground space wasted.
Enhanced Safety: Up high, out of reach of people and animals. Vandalism risk? Lower.
Durable: Closed design protects the oil. Lifespan? Often 30–60 years.
Easy Installation: Light enough for one pole. Quick to mount.
But it’s not all perfect.
Environmental Exposure: Wind, rain, climbing animals… all can cause damage.
Maintenance Challenges: If something breaks, you need to work up there. Not impossible-but costs go up.
