Three-Phase 50 kVA Oil-Immersed Power Distribution Transformer
Jan 22, 2026
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Core Advantages
The three-phase 50 kVA oil-immersed power distribution transformer converts high voltage to low voltage, typically from 10 kV to 0.4 kV, with minimal energy loss, ensuring consistent power supply for daily operations. High energy efficiency: the unit complies with IE2 efficiency standards, with no-load loss as low as 120 W and load loss of 850 W, reducing annual electricity consumption by 10 to 15 percent compared with traditional models. Superior heat dissipation: high-quality mineral insulating oil provides ONAN cooling, enabling continuous operation under full load even in high-temperature environments. Stable three-phase output: the three-phase design delivers balanced voltage, protecting motors, air conditioners, and industrial controllers from fluctuations. Durable structure: the core uses high-grade cold-rolled silicon steel sheets, and the tank is made of 3 mm thick galvanized steel with an anti-corrosion coating for outdoor installation. Low maintenance: the sealed tank design minimizes oil evaporation and contamination, requiring only annual oil sampling and testing.
Technical Specifications
| Parameter | Specification |
|---|---|
| Rated capacity | 50 kVA |
| Phase configuration | Three-phase, four-wire (3P4W) |
| Primary voltage | 10 kV (customizable: 6 kV / 20 kV) |
| Secondary voltage | 0.4 kV (400 V) |
| Frequency | 50 Hz / 60 Hz |
| Cooling method | ONAN |
| Insulation class | Class A (105 degrees C) |
| Temperature rise | Up to 55 K top oil / 80 K winding |
| Protection level | IP23 |
| Connection group | Dyn11 (Yyn0 optional) |
| Weight | Approximately 820 kg |
| Overall dimensions L x W x H | 1480 x 980 x 1350 mm |
| Noise level | Up to 52 dB at 1 m |
Typical Application Scenarios
Residential communities: supplies 200 to 300 households with power for air conditioners, refrigerators, and home appliances. Commercial districts: powers small shopping malls, office buildings, and hotels with mixed lighting, elevator, and HVAC loads. Small industrial plants: supports light manufacturing such as textile workshops and food processing facilities. Rural power grids: converts 10 kV to 0.4 kV for villages, farms, and agricultural irrigation equipment. Infrastructure auxiliary: provides power for road toll stations, communication base stations, and water treatment pump rooms.
Quality Control and Certification
Key components such as copper windings, silicon steel sheets, and insulating oil are tested by third-party laboratories to meet IEC 60076 requirements. Production uses automated winding machines with a tolerance of plus or minus 0.1 mm and laser cutting for the tank. Before delivery, each transformer undergoes insulation resistance testing (at least 1000 megaohms at 25 degrees C), a temperature rise test at full load for 8 hours, a short-circuit withstand test at 1.5 times rated current for 2 seconds, and an oil dielectric strength test of at least 35 kV. The unit complies with CE, IEC, GB/T 6451, and ANSI standards.
Frequently Asked Questions
Q: How many households can a 50 kVA transformer serve?
A: Under typical residential load profiles, a 50 kVA unit can supply 200 to 300 households when air conditioning and heating loads are moderate; the exact number depends on the coincident demand factor.
Q: What is the no-load loss of this transformer?
A: The no-load loss is as low as 120 W, and the load loss at rated current is 850 W, which together reduce annual energy consumption by 10 to 15 percent compared with conventional designs.
Q: What tests are performed before delivery?
A> Each unit is tested for insulation resistance, temperature rise at full load, short-circuit withstand, and oil dielectric strength, in addition to routine ratio, polarity, and loss measurements.
Q: Is the transformer suitable for outdoor installation?
A: Yes. The galvanized steel tank with anti-corrosion coating and IP23 protection is designed for outdoor use, though a weatherproof enclosure is recommended for extreme environments.
Q: Can the voltage ratio be customized?
A: Yes. Primary voltages of 6 kV, 10 kV, or 20 kV and secondary voltages of 0.4 kV or other values can be configured, with the insulation level adjusted to match.
Q: What maintenance is required?
A: The sealed design requires only annual oil sampling and testing of dielectric strength and moisture, plus routine inspection of bushings, tap changer, and accessories.
For the latest 50 kVA oil-immersed transformer price list and technical datasheet, contact our sales team with your voltage, installation environment, and load requirements.