The S11 Series 20kV to 400V Oil-Immersed Distribution Transformer is a high-performance power solution specifically engineered for Municipal Infrastructure Construction. Available in 250kVA and 315kVA capacities, this Three-Phase step-down transformer complies with IEC60076 international standards. It is designed to provide a stable, efficient, and cost-effective electricity supply for urban grids, public utilities, and large-scale residential developments in challenging environments.

• Superior Energy Efficiency: Utilizing high-permeability silicon steel cores, the S11 series significantly reduces no-load losses, helping municipal projects lower operational costs.
• Enhanced Durability & Longevity: Built with 100% pure oxygen-free copper windings, ensuring excellent thermal stability and a service life exceeding 25 years.
• Extreme Weather Resilience: The reinforced tank structure and anti-corrosive coating make it ideal for high-temperature and high-humidity climates.
• Zero Leakage Technology: Advanced hermetically sealed design prevents oil oxidation and moisture ingress, ensuring internal components remain pristine.
• Global Compliance: Fully certified for international engineering standards, making it the preferred choice for EPC firms and government tenders.

1. Rated Capacity: 250kVA / 315kVA (Dual rating support)
2. Voltage Ratio: 20kV primary to 0.4kV (400V) secondary
3. Vector Group: Dyn11 or Yzn11 (Optimized for unbalanced residential loads)
4. Cooling Method: ONAN (Oil Natural Air Natural) with high-efficiency corrugated radiators
5. Insulation Class: Class A, featuring high-grade mineral oil with high dielectric strength
6. Core Design: Three-column stacked core using cold-rolled grain-oriented (CRGO) silicon steel to minimize noise and eddy currents
7. Protection: Equipped with oil level gauges, pressure release valves, and multi-functional thermometer for real-time monitoring

In many African regions, fine sand and extreme dust are the primary challenges for electrical equipment. We have implemented specific engineering measures to address these difficulties:

• The Difficulty: Dust accumulation on seals often leads to premature aging of gaskets, causing oil seepage and internal contamination.
• Our Solution: We utilize Double-Sealed Nitrile Rubber Gaskets and a fully vacuum-filled corrugated tank. The tank is robotically welded to ensure zero gaps.
• Protection Upgrade: We apply a High-Gloss Electrostatic Powder Coating (UV-resistant). This smooth finish prevents dust from adhering to the surface, maintaining optimal heat dissipation and preventing the corrosion often triggered by sand abrasion.

• Q1: Does this transformer meet the specific grid standards of African countries?
  A1: Yes, our transformers are designed based on IEC standards and can be customized to match local utility requirements in Nigeria, Kenya, Ethiopia, and other regions.
• Q2: How do you support EPC firms during the tendering phase?
  A2: We provide comprehensive technical data sheets, type test reports, and 3D CAD drawings to ensure your project submission is technically superior.
• Q3: What measures are taken to prevent damage during inland African logistics?
  A3: We use heavy-duty steel channel bases and reinforced export packaging. The internal core is securely fastened to withstand vibrations on unpaved roads.
• Q4: Can this unit handle high ambient temperatures during summer peaks?
  A4: Absolutely. We have increased the radiator surface area by 15% compared to standard models to ensure safe operation at ambient temperatures up to 50°C.
• Q5: What is your typical lead time for bulk municipal orders?
  A5: For standard 250kVA/315kVA units, we maintain a production cycle of 15-25 days, with expedited options for emergency infrastructure repairs.
• Q6: Are spare parts readily available for maintenance?
  A6: While the S11 is virtually maintenance-free, we provide a standard "Easy-Replace" kit including bushings and gaskets for your peace of mind.