The Usune 750kVA three-phase dry type transformer is an oil-free power distribution unit that completely eliminates flammable insulating oil, relying instead on air for insulation and heat dissipation. This fundamentally resolves safety hazards associated with oil-immersed transformers, such as oil leaks, fires, and pollution. Leveraging standardized production lines and rigorous incoming material quality control, we have optimized the core and winding structures to balance safety, energy efficiency, and ease of installation. The equipment ensures stable, long-term operation at full load and demonstrates exceptional environmental adaptability. As a premier supplier of power distribution equipment, Usune provides highly stable dry-type transformer solutions to customers in both domestic and international markets.
The 750kVA three-phase dry type transformer utilizes high-temperature resistant insulation materials and contains no insulating oil; consequently, it does not suffer from oil leaks, fires, or explosions during overload or short-circuit conditions. It eliminates the need for auxiliary facilities such as oil pits or firewalls, significantly reducing infrastructure and safety-related investment costs for the distribution room.
Operation generates no waste oil and emits no harmful gases. It allows for direct indoor installation without the need for waste oil recovery equipment, fully meeting the stringent environmental compliance standards required for hospitals, schools, and subways.
The optimized laminated silicon steel core and compact winding structure effectively minimize electromagnetic vibration, resulting in low operating noise. Partial discharge levels are strictly controlled within domestic and international standards to prevent insulation aging, ensuring decades of stable, continuous operation.
Constructed with high-grade grain-oriented silicon steel cores, the unit exhibits significantly lower no-load and load losses compared to standard transformers. Long-term operation effectively reduces energy consumption and lowers electricity-related operating costs for the enterprise.
Features an air-insulated, naturally air-cooled structure that eliminates the need for periodic insulation oil testing or replacement. Routine maintenance requires only simple dust removal and inspections, resulting in substantial savings on labor and spare parts costs over the equipment's lifecycle.
Operates reliably in ambient temperatures ranging from -20°C to +40°C. It is suitable for indoor environments characterized by high humidity, altitudes up to 1,000 meters, and dusty conditions, making it ideal for specialized locations such as basements, tunnels, sterile medical wards, and educational buildings.
The 750kVA three-phase dry type transformer is compact and lightweight, minimizing the space required in the power distribution room. Standard lifting lugs and pre-configured terminals facilitate transport and hoisting, effectively shortening the installation timeline.
The Usune 750kVA three-phase dry type transformer achieves voltage transformation and power transmission based on the principle of electromagnetic induction. Its core operating logic is as follows:
1. Alternating current (AC) flowing through the primary winding generates a periodic alternating magnetic flux within the laminated iron core;
2. The alternating magnetic flux permeates the secondary winding, inducing an alternating electromotive force (EMF) in the secondary coil through electromagnetic induction;
3. Based on the turns ratio between the primary and secondary windings, the AC voltage is stepped up or stepped down to facilitate power transmission.Unlike oil-immersed transformers, this unit utilizes air as the primary medium for winding and core insulation as well as heat dissipation, eliminating the need for liquid insulating oil. Heat generated during operation is dissipated via natural convection or forced air cooling; the process is safe and hazard-free, ensuring reliable voltage transformation and power transmission.
| Item | Technical Parameter |
| Rated Capacity | 750 kVA (model range 30～2500 kVA customizable) |
| HV Rated Voltage | 10kV / 10.5kV |
| LV Rated Voltage | 0.4kV |
| Rated Frequency | 50/60Hz dual-frequency compatible |
| Vector Group | Dyn11 |
| Impedance Voltage | 4%～6%, standard configuration 6% |
| Item | Technical Parameter |
| Ambient Temperature | -20℃～+40℃ |
| Applicable Altitude | ≤1000m |
| Relative Humidity | ≤95%, no condensation allowed |
| Standard Installation Site | Indoor power distribution room, basement, underground space |
A Grade-A general hospital in East China replaced aging oil-immersed equipment with two Usune 750kVA three-phase dry type transformers to power critical equipment in the ICU, imaging center, and operating rooms.
- Project Challenges: Traditional oil-filled equipment posed fire risks, operational noise disturbed the patient care environment, and routine maintenance required significant manpower.
- Application Results: The oil-free structure met the hospital's strict fire safety standards; low partial discharge characteristics ensured the stable operation of precision medical equipment; the maintenance-free design reduced annual maintenance costs by 70%; and the equipment has operated fault-free for three consecutive years.
A food processing plant in Zhejiang adopted Usune 750kVA dry-type transformers to power production line machinery.
- Project Requirements: A clean, oil-free production environment; energy-efficient equipment; and suitability for dusty workshop conditions.
- Application Results: Low-loss cores effectively reduced the plant's power consumption; the air-insulated structure eliminated the risk of oil contamination for food ingredients; and the dust-resistant winding structure ensured continuous, stable operation in a dusty environment.
A1: The standard model is designed for indoor use, suitable for environments at altitudes ≤1000m, temperatures between -20°C and +40°C, and humidity ≤95% (non-condensing). For outdoor use, protective enclosures and rainproof structures can be customized to suit complex outdoor conditions.
A2: Compared to oil-immersed transformers, this product eliminates the need for oil changes, oil testing, and oil pit cleaning, classifying it as maintenance-free equipment. However, quarterly inspections are recommended to check for dust accumulation on windings, terminal tightness, and ventilation airflow; preventing dust-induced airflow blockage helps maintain heat dissipation and extends the equipment's service life.
A3: Usune units come standard with the Dyn11 vector group, featuring low zero-sequence impedance and strong capabilities for suppressing three-phase load unbalance and harmonics, thereby stabilizing the 0.4kV output voltage. They are well-suited for applications with significant single-phase loads—such as hospitals, commercial buildings, and factories—effectively minimizing the impact of voltage fluctuations on sensitive equipment.
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