Hermetically‑sealed oil‑filled distribution transformer with corrugated wound‑core tank, no conservator tank. Reduces no‑load loss 25‑35% for near‑zero‑maintenance operation. IEC & GB compliant, available in three‑phase and pad‑mounted types. Perfect for mining, metallurgy, petrochemical and utility harsh‑environment power distribution.
Key Features & Advantages
• Fully Sealed Corrugated Tank
Replaces traditional oil conservator and radiators; wave fins handle thermal expansion/contraction naturally, isolating oil from air to slow aging and prevent insulation moisture.
• Maintenance-Free Operation
Normal running requires no routine maintenance due to enhanced sealing and improved components.
• Energy-Efficient Rolled Core
High-quality cold-rolled silicon steel wound core eliminates traditional seams, lowering no-load losses by 25%–35% and no-load current by 60%–80%, while reducing noise for a more eco-friendly distribution transformer.
• Strong Short-Circuit Resistance
Integrated core clamping strengthens coil anti-short-circuit capability.
• Robust Surface Treatment
Oil tank undergoes degreasing, derusting, and phosphating, then coated with three-proof paint for excellent corrosion resistance in harsh environments (metallurgy, petrochemical, mining).
• Compact & Aesthetic Design
Smaller footprint than conventional units with traditional oil tubes; beautiful appearance suitable for space-constrained installations.
• High Reliability & Long Life
Bolted or welded tank-cover connection prevents oil-air contact, extending transformer lifespan and improving operational reliability over standard oil-immersed designs.
These features make it a preferred choice in the oil filled distribution transformer market, outperforming many dry type distribution transformer alternatives in cooling and heavy-load scenarios while offering the reliability expected from a quality electrical distribution transformer.
Specifications & Parameters
Our three phase distribution transformer is available in a wide range of standard ratings (customizable upon request). Typical parameters include:
| Category | Specification / Description |
| Rated Capacity | 50 kVA to 2500 kVA (common: 100, 200, 315, 500, 630, 800, 1000, 1250, 1600, 2000 kVA) |
| Rated Voltage | HV: 6 kV / 10 kV / 11 kV / 20 kV / 35 kV; LV: 0.4 kV / 0.433 kV (others available) |
| Frequency | 50 Hz / 60 Hz |
| Phase | Three-phase |
| Connection Group | Dyn11 (or per customer specification) |
| Cooling Method | ONAN (Oil Natural Air Natural) |
| Temperature Rise | Top oil ≤ 60°C, Winding ≤ 65°C (standard) |
| Impedance Voltage | 4%–6% (depending on capacity) |
| Tapping Range | ±2 × 2.5% or as specified |
| Core Type | Wound/rolled core from low-loss cold-rolled silicon steel |
| Tank Type | Hermetically sealed corrugated (wave) tank |
| Insulating Liquid | Mineral oil (or biodegradable options on request) |
| Standards Compliance | IEC 60076, IEEE C57, or equivalent national standards |
| Exact no-load and load losses are optimized per capacity for high efficiency (e.g., significantly below traditional designs). Dimensions, weight, and oil volume vary by rating—contact us for detailed datasheets tailored to your electrical distribution transformer needs. Suitable for both pole-mounted and pad mounted distribution transformers installations. |
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Packaging, Warranty & Certifications Packaging：
Robust wooden crate or container packaging with moisture-proof and shock-resistant measures for safe international transport. Accessories (bushings, nameplate, etc.) securely fastened.
Warranty：
Standard 12-18 months warranty against manufacturing defects (extendable options available). Covers core, windings, tank, and insulation system.
Quality Certifications：
ISO 9001 (Quality Management), ISO 14001 (Environmental), CE marking (where applicable), and type-test reports per IEC/IEEE standards. PCB-free oil certification and compliance with relevant energy efficiency regulations.
Technical Support：
This oil filled distribution transformer combines proven reliability with modern sealed technology, making it an excellent long-term investment for any power distribution project.
Contact us for custom solutions, quotations, or the latest insights related to power grid transformer information.
Internally, the core is wound rather than stacked. Rolling it from low-loss cold-rolled silicon steel removes most of the transverse and longitudinal joints, and fewer joints mean lower no-load current, fewer reactive losses and quieter running. The tank is light-grey steel with high-efficiency cooling fins and a bolted or welded cover that keeps the oil sealed inside. Before any paint goes on, the tank is degreased, derusted and phosphated; the three-proof topcoat then stands up to the corrosive air found around smelters, chemical plants and coastal sites. The insulating oil is a low-toxicity mineral grade, with biodegradable options available on request. Core winding, tank fabrication and finishing all happen under one roof — the build you would expect from established distribution transformer manufacturers.
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.
A conventional oil immersed distribution transformer keeps a conservator above the tank and lets the oil breathe through a breather. This design removes that route completely: the corrugated fins expand and contract with the oil, so the insulating liquid never contacts air and there is no breather to service. With less moisture and oxygen in the oil, ageing slows and service life is longer.
Under normal running conditions there is no routine maintenance to schedule. The sealed tank removes oil top-ups and breather checks, and the internal components are selected for long service intervals. We still recommend the visual inspections set out in the manual — tank, bushings, nameplate and connections — and our team can help you set an inspection routine that suits the site.
Yes. Capacity, high-voltage and low-voltage ratings, impedance, tapping range and connection group are all set to your specification, and Dyn11 is only our standard starting point. As distribution transformer manufacturers we adapt the core, winding and tapping design rather than ask you to accept a stock unit.
Oil filled units cool more effectively and carry more overload in outdoor or harsh conditions, which is usually the better fit for mining, petrochemical and heavy industrial sites. Dry type transformers remain the usual choice indoors or where oil is restricted. Send us the load profile and site conditions and we will give you a straight comparison.
Standard builds use low-toxicity mineral oil, and biodegradable insulating liquids are available on request. As a power transformer supplier we confirm the oil choice at the drawing stage so it matches your environmental and fire-safety requirements. If your project carries a specific oil specification, tell us early and we will build it into the design.
Yes. The sealed tank has no conservator and no external radiator bank, so the unit suits both pad-mounted enclosures and pole-mounted three phase distribution transformer installations. Final mounting details depend on the enclosure or pole hardware you use, so confirm the arrangement at the drawing stage and we will match the tank, bushings and lifting supports it.
