Stable power supply, safe and reliable! Our single-phase pole-mounted transformer safeguards your electrical needs.
01 General
1.1 Project Description
75 kVA 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 34.5GrdY/19.92kV with ±2*2.5% tapping range (NLTC), the secondary voltage is 0.24/0.12kV, they formed a vector group of Ii0.
A single-phase pole mounted transformer is a type of power transformer that is mounted on a telephone pole and is primarily used in distribution systems to reduce high voltages to low voltages suitable for domestic, commercial or small industrial users. It is mounted on a pole and fixed by a bracket or suspension device for easy maintenance and floor space saving. Suitable for medium and low voltage distribution network, mainly used in residential areas, agricultural irrigation, small commercial places and other scenarios with low load. Transformers are also equipped with durable porcelain or composite insulators to ensure long-term performance in different environmental conditions.
Single-phase pole mounted transformer works on the principle of electromagnetic induction. When the high voltage side winding is connected to the AC power supply, the alternating current generates an alternating magnetic field in the iron core, which induces the electromotive force in the low voltage side winding to complete the voltage transformation. The ratio of the input voltage on the voltage side and the output voltage on the low voltage side is proportional to the ratio of turns on both sides of the winding.
1.2 Technical Specification
75 kVA transformer specifications type and data sheet
| Delivered to | Canada |
| Year | 2024 |
| Type | Single phase pole mounted transformer |
| Standard | IEEE C57.12.20 |
| Rated Power | 75 kVA |
| Frequency | 60 HZ |
| Phase | 1 |
| Cooling Type | ONAN |
| Primary Voltage | 34.5GrdY/19.92 kV |
| Secondary Voltage | 0.24/0.12 kV |
| Winding Material | Aluminum |
| Angular displacement | Ii0 |
| Impedance | ≥1.5% |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5% |
| No Load Loss | 0.143KW |
| On Load Loss | 1.154KW |
| Accessories | Standard Configuration |
1.3 Drawings
75 kVA pole mounted transformer diagram drawing and size.
02 Manufacturing
2.1 Core
| The coil core used by the single-phase column transformer is one of its core components, which is used to provide the path of magnetic flux, so as to achieve electromagnetic induction. Compared with the traditional laminated core, the rolled core avoids cutting joints and improves the magnetic flux continuity of the core. The continuity of the coil core significantly reduces hysteresis and eddy current losses, thereby improving the efficiency of transformer operation. The iron core has no splicing gap, and the magnetic flux distribution is uniform, which effectively reduces the vibration and noise in operation. Reduces joint air gaps in conventional iron cores, reduces the risk of local overheating, and extends equipment life. |  |
2.2 Winding
 | Foil wound low voltage winding provides low resistance path, wire wound high voltage winding provides uniform voltage distribution, the overall electromagnetic performance is superior. Low voltage foil winding and transformer oil contact area, higher heat dissipation efficiency; The high voltage wire winding has good temperature rise control due to its compact distribution. The foil winding has high short-circuit resistance and the wire winding structure is stable. The combination of the two improves the reliability of the transformer. The foil winding saves cross-sectional space, the wire winding is compact, and the overall design is more lightweight and efficient. |
2.3 Tank
| Made of high quality steel plate with high strength and corrosion resistance. The tank wall is designed with corrugated sheets to improve heat dissipation efficiency. Fitted with sealing washers and bolts to ensure tank tightness and prevent transformer oil leakage and external moisture from entering. The transformer oil circulates in the tank by natural convection, transferring the heat generated during the operation of the iron core and coil to the tank wall and eventually to the outside world. Transformer oil completely submerges the core and windings, providing excellent electrical insulation and preventing short circuits between the windings or between the windings and the fuel tank. The tank provides physical protection for the core and windings against shock, vibration or contamination from the external environment. |  |
2.4 Final Assembly
 | Core and Winding Assembly: Combine the core and completed primary and secondary windings, ensuring a tight fit with no looseness. Tank Installation: Place the assembled core and windings into the transformer tank, secure them according to specifications, and leave openings for connections. Insulation and Sealing: Install insulators, sealing gaskets, and terminals to ensure proper insulation for high-voltage and low-voltage connections. Oil Filling and Air Removal: Fill the transformer with insulating oil and remove air from the tank to ensure the oil fully covers the windings and core, preventing localized overheating. |
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: Ii0 | -0.07 | Pass |
| 3 | Polarity tests | / | Subtractive | Subtractive | Pass |
| 4 | No-load losses and excitation current | % | I0 :: provide measured value | 0.18 | Pass |
| kW | P0: provide measured value(at 20℃) | 0.122 | |||
| / | the tolerance for no load loss is ±10% | / | |||
| 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 ±6% | / | Pass |
| % | Z%: measured value | 3.30 | |||
| kW | Pk: measured value | 1.117 | |||
| kW | Pt: measured value | 1.239 | |||
| % | Efficiency not less than 98.5% | 99.01 | |||
| 6 | Applied Voltage Test | / | LV: 10kV 60s | No collapse of the test voltage occurs | Pass |
| 7 | Induced Voltage Withstand Test | / | Applied voltage (KV):0.48 | No collapse of the test voltage occurs | Pass |
| Duration(s):48 | |||||
| Frequency (HZ): 150 | |||||
| 8 | Insulation Resistance Measurement | GΩ | LV-HV to Ground | 47.2 | Pass |
| 9 | Leakage Test | / | Applied pressure：20kPA | No leakage and no Damage | Pass |
| Duration：12h | |||||
| 10 | Oil Test | kV | Dielectric Strength | 57.1 | Pass |
| mg/kg | Moisture Content | 9.9 | |||
| % | Dissipation Factor | 0.00211 | |||
| mg/kg | Furan Analysis | / | |||
| / | Gas Chromatography Analysis | / |
04 Packing and Shipping
05 Site And Summary
In modern power systems, single-phase pole-mounted transformers have become a reliable solution for efficient power transmission due to their excellent performance and stable power supply. Whether in residential areas, commercial properties, or industrial environments, they play a vital role. Our single-phase pole-mounted transformers not only offer high-efficiency energy conversion but are also subjected to rigorous quality control, ensuring safety and durability. By choosing our products, you will receive high-quality power support to assist your project’s success. Thank you for your interest in our products; feel free to contact us for further information!
