Crafting excellence, delivering the future—Single-phase pole-mounted transformers, illuminating every watt of the world.
01 General
1.1 Project Description
75 kVA single phase pole mounted transformer was delivered to Canada in 2024. The rated power of the transformer is 75 kVA with ONAN cooling. The primary voltage is 34.5kV with ±2*2.5% tapping range (NLTC), the secondary voltage is 0.12/0.24kV, they formed a vector group of Ii6.
A utility pole transformer is a type of power transformer mounted on a telephone pole, usually located along streets, highways, or in rural areas. These transformers play a vital role in the distribution of power from the transmission line to the user, and are intermediate devices that regulate voltage levels and ensure safe and efficient power supply. A single-phase pole mounted transformer is an electrical device used to transmit electrical energy between two or more circuits by electromagnetic induction. It usually consists of two wire coils (called primary and secondary winding) wound around a common magnetic core. When alternating current (AC) flows through the primary winding, it creates a changing magnetic field in the core, which in turn induces a voltage in the secondary winding. This voltage can be higher or lower than the primary voltage, depending on the ratio of turns between the primary and secondary windings.
1.2 Technical Specification
75kVA single phase utility pole transformer specification and data sheet
| Delivered to | Canada |
| Year | 2024 |
| Type | Single phase pole mounted transformer |
| Standard | CSA C2.2 |
| Rated Power | 75KVA |
| Frequency | 60HZ |
| Phase | Single |
| Cooling Type | ONAN |
| Primary Voltage | 34.5KV |
| Secondary Voltage | 0.24/0.12KV |
| Winding Material | Aluminum |
| Polarity | Additive |
| Impedance | 1.5% |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5% |
| No Load Loss | 0.205KW |
| On Load Loss | 0.870KW |
| Accessories | Standard Configuration |
| Remarks | N/A |
1.3 Drawings
75kVA utility pole transformer dimensions and weight details
02 Manufacturing
2.1 Core
| The core is made of premium cold-rolled grain-oriented silicon steel sheets, often enhanced with special surface treatments to minimize core loss. The core is constructed using a continuous winding process, forming a seamless, closed magnetic circuit. This design significantly reduces the magnetic resistance caused by joints. The wound core ensures a uniform and continuous magnetic path, reducing hysteresis and eddy current losses, thereby enhancing efficiency. The wound core typically has a regular shape, which reduces volume and weight, meeting the demand for lightweight and easy installation. |  |
2.2 Winding
 | Precisely designed turns ratio ensures the voltage and current relationship between the primary and secondary windings meets specifications. Minimizes leakage magnetic loss through optimized conductor cross-sections and arrangement, ensuring efficient energy transfer. High-strength clamping structures enhance resistance to short-circuit forces, preventing mechanical deformation caused by electromagnetic stress. Heat generated within the winding is efficiently dissipated through inter-layer cooling channels or circulation of insulating oil, preventing excessive temperature rise. |
2.3 Tank
| The tank is usually made of high-quality stainless steel, with high mechanical strength and corrosion resistance, ensuring long-term stable operation of the tank in harsh environments. The exterior is coated with anti-rust and anti-corrosion paint, often in light gray or other environmentally friendly finishes, protecting against rust and extending the tank’s service life. Advanced sealing welding techniques ensure strong, leak-proof seams, maintaining the safe storage of transformer oil. Advanced sealing welding techniques ensure strong, leak-proof seams, maintaining the safe storage of transformer oil. |  |
2.4 Final Assembly
 | (1) Coil Winding and Assembly:
(2) Insulation Treatment:
(3) Tank Assembly:
(4) Installation of External Components:
03 Testing |
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 | 0.00 | Pass |
| 3 | Polarity tests | / | Additive | Additive | Pass |
| 4 | No-load losses and excitation current | % | I0 :: provide measured value（100%） | 0.30 | Pass |
| kW | P0: provide measured value（100%） | 0.186 | |||
| % | I0 :: provide measured value（105%） | 1.15 | |||
| kW | P0: provide measured value（105%） | 0.268 | |||
| / | the tolerance for no load loss is ±15% | / | |||
| 5 | Load losses , impedance voltage,total losses and efficiency | / | t:85℃ the tolerance for impedance is ±7.5% the tolerance for total load loss is ±8% | / | Pass |
| % | Z%: measured value | 2.55 | |||
| kW | Pk: measured value | 0.841 | |||
| kW | Pt: measured value | 1.027 | |||
| % | Efficiency not less than 98.94% | 99.01 | |||
| 6 | Applied Voltage Test | / | HV:50KV 60S LV: 10kV 60s | No collapse of the test voltage occurs | Pass |
| 7 | Induced Voltage Withstand Test | / | Applied voltage (KV):69 | No collapse of the test voltage occurs | Pass |
| Duration(s):60 | |||||
| Frequency (HZ): 120 | |||||
| 8 | Insulation Resistance Measurement | GΩ | HV-LV to Ground : LV-HV to Ground: HV&LV to Ground: | 102.8 79.5 77.3 | Pass |
| 9 | Leakage Test | / | Applied pressure：20kPA | No leakage and no Damage | Pass |
| Duration：12h | |||||
| 10 | Oil Test | kV | Dielectric Strength | 55.4 | Pass |
| mg/kg | Moisture Content | 9.8 | |||
| % | Dissipation Factor | 0.00257 | |||
| mg/kg | Furan Analysis | 0.03 | |||
| / | Gas Chromatography Analysis | / |
04 Packing and Shipping
05 Site And Summary
Utility pole transformer is a kind of important equipment widely used in power distribution system. It is favored for its compact structure, easy maintenance and high cost efficiency. Because of its key role in the power system, it is very important to keep the single phase column transformer in good running condition to ensure the stability and security of the power supply. Our expertise ensures reliable, efficient power distribution solutions that meet the unique requirements of each project.
