Upgrade your grid with single phase pole mounted transformer - steady performance, easy installation.
01 General
1.1 Project Description
50 kVA single phase pole mounted transformer was delivered to Guyana in 2025. The rated power of the transformer is 50 kVA with ONAN cooling. The high voltage is 13.8 kV with ±2*2.5% tapping range (NLTC), the low voltage is 0.12/0.24 kV, they formed a vector group of Ii0.
Our 50 kVA, transformer power pole designed for step-down service in overhead distribution networks. The transformer features a high-voltage (primary) rating of 13.8 kV, which is a common distribution voltage level for rural and suburban feeders, and a low-voltage (secondary) rating of 0.12/0.24 kV (120/240 V) – a split-phase configuration that provides both 120 V for general lighting and receptacle loads and 240 V for larger appliances such as water pumps, air conditioners, or small machinery.
With a nominal power capacity of 50 kVA, this unit is ideally suited for supplying a small cluster of residential customers, a small commercial facility, or an agricultural service point. The transformer is designed for pole-mounting using standard brackets or a davit arm, ensuring easy access for maintenance and disconnection. Its enclosure is weather-sealed and filled with dielectric fluid (typically mineral oil or an environmentally friendly alternative) to provide electrical insulation and efficient heat dissipation.
Primary terminations are equipped with two bushings (live-front design) or a single bushing with a grounded tank (dead-front design), compatible with external fuse cutouts, surge arresters, and grounding systems. The secondary side provides a three-wire output (L1, L2, neutral) with the neutral bonded to the tank and the system ground for safety. This 50 kVA transformer meets relevant ANSI/IEEE standards for temperature rise, impedance, and insulation levels, ensuring reliable operation in outdoor environments with varying ambient temperatures and loading patterns.
1.2 Technical Specification
50 kVA transformer power pole specifications type and data sheet
| Delivered to | Guyana |
| Year | 2025 |
| Type | Pole mounted transformer |
| Standard | IEEE & ANSI C57.12.00 |
| Rated Power | 50 kVA |
| Frequency | 60HZ |
| Phase | 1 |
| Polarity | Subtractive |
| Cooling Type | ONAN |
| Primary Voltage | 13.8 kV |
| Secondary Voltage | 0.12/0.24 kV |
| Winding Material | Copper |
| Angular displacement | Ii0 |
| Impedance | 2% |
| Tap Changer | ±2*2.5%(total range=10%) |
| No Load Loss | 0.16 kW |
| On Load Loss | 0.512 kW |
| Total loss | 0.672 kW |
1.3 Drawings
50 kVA transformer power pole diagram drawing and size.
02 Manufacturing
2.1 Core
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2.2 Winding
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2.3 Tank
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2.4 Final Assembly
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03 Testing
3.1 Test Equipment (ISO 17025-Compliant Lab)
- 0.05-class 3-phase power analyzer
- 0.1-class automatic ratio bridge
- Partial discharge measurement system
- Insulation resistance tester (0.1MΩ – 1000GΩ)
- Automatic oil dielectric tester (2kV/s, 6 repeats)
- 200kV/5A AC withstand voltage system
- Precision pressure sensors (0.1 class) for leak tests
3.2 Test Results
We apply rigorous test methods to ensure long-term reliability. Key tests and results are summarized below.
| Test Item | Method / Condition | Requirement | Measured Result | Conclusion |
| Resistance measurement | Voltmeter-ammeter method, computer-controlled DVM, cold resistance | Consistent design values | LV loop resistance (120V): 14.278 & 14.622 Ω – very low deviation | ✅ Pass |
| Ratio test | IEEE ratio bridge; balance at R/R1 | Deviation ≤0.5% | Main tap deviation: 0.00% | ✅ Pass |
| Polarity | Ratio meter | Subtractive | Subtractive | ✅ Pass |
| No-load loss & current | Rated voltage excitation | P0 ≤184W (guaranteed 160W +15%) | P0 = 148W (12W lower); I0 = 1.021% | ✅ Better than spec |
| Load loss, impedance, efficiency | 85℃, short-circuit method; power analyzer | Z% tolerance ±10%; total loss ≤+6% | Z% = 2.08%; Pk=503W; Total loss 651W (target 672W); Efficiency 98.96% | ✅ Pass |
| Applied voltage test | HV: 34kV/60s; LV: 10kV/60s | No breakdown | HV 34kV/60s, LV 10kV/60s – no collapse | ✅ Pass |
| Induced voltage test | 2× rated voltage (27.6kV), 150Hz, 48s | No breakdown | Applied 30.48kV for 48s – passed | ✅ Pass |
| Insulation resistance | Insulation resistance tester (GΩ range) | >10 GΩ recommended | HV-LV to ground: 96.2 GΩ; LV-HV to ground: 38.4 GΩ; HV&LV to ground: 50.4 GΩ | ✅ Excellent |
| Leak test (sealing) | 20 kPa oil pressure, 12 hours | No leakage, no damage | 20 kPa / 12h – no leakage, no damage | ✅ Pass |
| Oil dielectric strength | 6 samples, 2kV/s ramp, 25mm gap | ≥45 kV | Average 66.06 kV (range 63.8–69.2 kV) | ✅ Superior |
3.3 Key Reliability Takeaways
- Insulation resistance >96 GΩ ensures safe operation in humid or polluted environments.
- Oil dielectric strength of 66 kV (well above 45 kV) indicates excellent oil quality and dry insulation.
- Sealing test at 20 kPa for 12h guarantees no oil leakage over decades of service.
- High efficiency (98.96%) reduces operating costs and heat generation.
04 Packing and Shipping
4.1 Packing
- Standard: Export-grade, moisture-proof and shock-proof (IP20 / IP54 optional).
- Internal protection: Tank filled with dry nitrogen or insulating oil – prevents rust during transit.
- Base design: Welded steel base with lifting holes for slings.
- Shock absorption: Elastic pads at bottom – suitable for sea, air, and road freight (5-10Hz vibration).
- Exterior cover: Waterproof plastic film + multi-layer corrugated cardboard – dust and moisture protection.
4.2 Shipping
- Lead time: Short – annual capacity >10,000 units.
- Documentation: Each transformer includes English test report, data sheet, certificate of conformity, installation manual.
- Torque check: All HV and LV terminal bolts are re-torqued before packing.
- Compact size: Easy container loading (dimensions: 925×675×695 mm, weight 263 kg).
- Shipping documents: Packing list, commercial invoice, COO, export declaration, tracking number.
05 Site And Summary
In summary, our single-phase pole mounted transformer offers the advantages of compact structure, reliable operation, low losses, and maintenance-free performance, making it an ideal choice for urban and rural distribution networks, rural grid upgrades, residential communities, and temporary power supply applications. Each transformer is manufactured in strict compliance with international and industry standards, with full-process quality control to ensure long-term stable operation even in harsh environments. Choosing us means not only selecting a high-quality product but also gaining access to professional technical support and lifecycle service guarantees. For more information or customized solutions, please feel free to contact us.
