Heavy‑duty three‑phase oil‑immersed distribution transformer, IEC & GB certified. Low‑loss, low‑noise performance with corrosion‑resistant steel tank and premium silicon‑steel core. Custom ratings, taps and mounting available for commercial, industrial and harsh‑environment power distribution grids.
Key Features & Advantages
Our oil immersed distribution transformers are engineered as static electrical devices that transform AC voltage and current based on electromagnetic induction principles, efficiently transmitting electrical energy while directly supplying power to end users. These robust units deliver reliable performance in various power distribution networks.
• Advanced Core Design
Utilizes novel high-permeability silicon steel core with full oblique seven-step lap joints for uniform magnetic flux distribution, significantly reducing no-load excitation current and core losses.
• Premium Windings
High and low voltage windings made from high-quality oxygen-free copper wire with multi-layer cylindrical structure for excellent electrical performance and durability.
• Hermetically Sealed Tank
Fully sealed corrugated radiator tank design ensures an aesthetic appearance, compact footprint, and effective protection against environmental factors while allowing thermal expansion.
• Optimized Cooling System
Axial oil ducts inside the coils direct oil flow toward high-temperature areas for superior heat dissipation, lower temperature rise, and higher overload capacity.
• Robust Construction
Axial clamping, special lifting plates, advanced fasteners, and proven processes enable the transformer to withstand transportation vibrations. The no-core-lifting design saves inspection time and costs.
• Eco-Friendly & Low Maintenance
Oil-immersed technology provides excellent insulation and cooling without pollution, low noise, high efficiency, and virtually maintenance-free operation over a long service life.
These features make our transformers ideal for urban and rural power grids, industrial facilities, commercial buildings, and renewable energy integration, answering common questions like“what do power transformers do” and “what is inside a power transformer” — a high-grade magnetic core, copper windings, and insulating/cooling oil all housed in a durable sealed tank.
Specifications & Parameters
Our 3 phase distribution transformer series is available in a wide range of ratings to meet diverse application needs. Typical technical parameters (custom configurations available upon request):
| Category | Specification / Description |
| Rated Capacity | 50 kVA to 2500 kVA (or higher on demand) |
| High Voltage (HV) | 6 kV, 6.3 kV, 10 kV, 10.5 kV, 11 kV, 20 kV, 33 kV (±2×2.5% or ±5% tapping range) |
| Low Voltage (LV) | 0.4 kV, 0.415 kV, 0.433 kV, 0.69 kV (Customizable) |
| Frequency | 50 Hz / 60 Hz |
| Vector Group | Dyn11, Yyn0, Yzn11 (common for distribution applications) |
| Cooling Method | ONAN (Oil Natural Air Natural) |
| Impedance Voltage | 4% ~ 6% |
| No-load Loss | Optimized low values per capacity (e.g., significantly reduced compared to conventional designs) |
| Load Loss | Low copper losses at 75°C |
| Temperature Rise | Top oil ≤ 60°C, winding ≤ 65°C (standard limits) |
| Insulating Oil | High-quality mineral oil (or eco-friendly options) |
| Altitude | ≤ 1000 m (custom designs for higher altitudes available) |
| Short-Circuit Withstand | Designed to meet IEC/IEEE standards |
| These parameters ensure high efficiency, low losses, and reliable operation even under fluctuating loads, making them suitable for demanding high voltage power transformers roles in the power grid. | |
Packaging, Warranty & Certifications Packaging：
Transformers are securely packed in robust wooden crates or seaworthy containers with protective measures against moisture, shock, and vibration during transportation. All units undergo rigorous factory testing before shipment.
Warranty：
Standard 12–18 months from commissioning (or up to 36 months from shipment), covering manufacturing defects. Extended warranty options and service packages are available for peace of mind.
Quality Certifications：
Compliance with IEC 60076 series
- IEEE/ANSI C57 standards where applicable
- ISO 9001 quality management system
- Additional certifications such as UL, CE, or others available upon specific market requirements.
Technical Support：
As a professional distribution transformer suppliers, we focus on delivering safe, efficient, and compliant products that support stable power grid operations.
Contact us for custom solutions, quotations, or the latest insights related to power grid transformer news today. Our oil immersed transformers combine advanced technology with proven reliability for long-term value in any distribution network.
An oil immersed distribution transformer that suits one site can be wrong for the next, so the last part of the specification is usually settled with your own engineers. Altitude, ambient temperature, humidity and dust all affect how the insulation and cooling are dimensioned, and a poorly ventilated electrical room is a different case from an open plinth outdoors. The tank is finished in a corrosion-resistant light grey coating that holds up in coastal or industrial air. Insulating oil is worth deciding early as well: high-grade mineral oil is the standard fill, and eco-friendly alternatives are available where a project carries an environmental requirement. Vector group and tapping are matched to your earthing arrangement and to the way load is balanced across the phases, and the mounting arrangement and cable entry are agreed on the drawings before production starts.
Buying a transformer for a project needs more than a catalogue number. Our engineering team works with you from the first enquiry: reviewing your load, duty cycle and grid conditions, then matching the right rectifier or oil-immersed distribution transformer to the application. We support customised and OEM builds, and where certification applies our units are supplied to IEC 60076 and CE/ISO standards. After delivery we stay involved with installation and commissioning guidance and troubleshooting support, backed by warranty and global service.
Keep it in its crate or on its pallet in a dry, well-ventilated place, clear of standing water, dust and corrosive fumes. Leave the fittings and cable boxes covered until commissioning, and do not store anything against the tank walls. Site delays are common on projects, so tell us at the order stage if the unit will stand for a long period and we will send the storage and preservation notes that apply to it.
Most of the hum comes from the core itself: with every cycle it magnetises and de-magnetises, the laminations change dimension very slightly, and anything flexible around them turns that movement into sound. The magnetic circuit in these units is designed so the flux crosses evenly, and the sealed tank is stiff rather than a light sheet-metal cover, so there is little to amplify. Where a sound limit applies — a power grid transformer standing beside housing, offices or a hospital — tell us the figure you have to meet and we will confirm the level for your rating.
Yes. Ratings, voltages, impedance and vector group are all set from your network data at the design stage, so the unit is built to your drawing rather than picked from a stock list. As power distribution transformer suppliers working project by project, we start from your single-line diagram and send drawings for approval before anything is manufactured. If your network has an unusual earthing arrangement or a heavily unbalanced single-phase load, mention it early, because it changes how the winding and vector group are specified.
Cooling is by natural oil circulation and natural air flow, with no fans or pumps involved. For an oil immersed power transformer that is the simplest arrangement there is: heat leaves the windings through the oil and then through the tank walls to the surrounding air, so there is nothing to switch on as load rises and nothing to service. It suits sites where routine attention is limited. If your duty cycle stays hot for long periods, or the unit will sit in a poorly ventilated room, tell us at the enquiry stage and we will confirm whether the standard rating is right for that location.
Less than most people expect. The oil circuit is sealed, so normal operation does not call for filter changes or a regular oil top-up routine. What is worth doing is a periodic walk-round: look for oil weeping around gaskets, valves and tank seams, and note anything that changes — a slow weep, a warmer tank than usual, or a difference in the sound of the unit. Service guidelines are supplied with every transformer, and our engineers can talk your maintenance team through them.
Both are normal. Outdoors the unit usually stands on a prepared concrete base; indoors it goes into an electrical room with a clear path for air to move around the tank. What decides the layout is clearance and ventilation rather than the transformer itself, and units are often installed close to the load they serve because cable runs are short. Send us the room or base dimensions and how the space is ventilated, and we will confirm what the installation needs.
