High-Efficiency Three Phase Distribution Transformers (10 kVA to 5 MVA)
Kokila Electricals engineers and manufactures premium-grade oil-immersed and dry-type distribution transformers customized for international utilities, heavy industrial complexes, and commercial electrical infrastructure. Operating under strict ISO 9001:2015 quality management systems, our distribution units deliver unmatched energy efficiency, low operational sound levels, and robust short-circuit withstand capabilities.
Designed in compliance with international engineering standards such as IEC 60076, IEEE C57, ANSI, and IS 1180, our transformers operate reliably under ambient temperatures up to 55°C and extreme environmental conditions. Each unit features optimized magnetic flux distribution, high-grade electrolytic copper/aluminum windings, and superior dielectric insulation fluids for a 25+ year operational lifespan.
Standard Technical Specifications
Custom electrical parameters, non-standard voltage ratios, and specialized enclosures are tailored to client project requirements.
| Parameter / Feature | Standard Specification / Range |
|---|---|
| Power Rating (kVA/MVA) | 10 kVA up to 5,000 kVA (5 MVA) — 3-Phase / 1-Phase |
| Primary Voltage Class | 3.3 kV, 6.6 kV, 11 kV, 22 kV, 33 kV (Up to 36 kV system voltage) |
| Secondary Voltage Class | 400V / 415V / 433V / 480V (Custom secondary voltages available) |
| Frequency | 50 Hz / 60 Hz |
| Cooling Method | ONAN (Oil Natural Air Natural) / ONAF / KNAN (Biodegradable Ester) |
| Vector Group | Dyn11, Dyn5, Yyn0, or as specified by procurement engineer |
| Tap Changer Type | Off-Circuit Tap Changer (OCTC: ±2.5% to ±5%) / On-Load Tap Changer (OLTC) |
| Core Material | High-permeability Cold Rolled Grain Oriented (CRGO) Silicon Steel / Amorphous Metal |
| Winding Material | High-conductivity Electrolytic Grade Copper / E.C. Grade Aluminum |
| Insulation Class | Class A (Oil-Immersed) / Class F & H (Dry Type / Cast Resin) |
| International Standards | IEC 60076, IEEE C57.12.00, ANSI, BS 171, IS 1180 (Level 1, 2, 3) |
Engineered for Maximum Reliability & Safety
Key design attributes engineered into every Kokila distribution transformer.
Low Core Loss & High Efficiency
Utilizing step-lap mitred CRGO core lamination designs to minimize no-load losses, eddy currents, and magnetizing noise, ensuring maximum energy efficiency under fluctuating load profiles.
High Short-Circuit Strength
Thermally improved insulation paper and robust mechanical clamping structures protect windings against severe electrical impulses, grid transients, and mechanical stresses during short-circuit faults.
Corrosion-Resistant Tank Enclosures
Heavy-duty mild steel (MS) tanks subjected to shot-blasting, anti-corrosive primer coating, and polyurethane/epoxy painting designed to withstand aggressive marine and tropical atmospheric corrosion.
Optimal Thermal Dissipation
Precision-welded press-steel radiator panels or corrugated tank fins maximize oil convection and air cooling, keeping oil and winding temperature rises well within specified safety limits.
Flexible Mounting Configurations
Available as Pole-Mounted distribution units for overhead power lines, Pad-Mounted transformers for underground urban distribution, or Substation-type distribution units.
Hermetically Sealed Options
Maintenance-free hermetically sealed designs prevent ambient air and moisture contact with dielectric oil, preserving oil quality and eliminating the need for silica gel breathers.
Quality Assurance & Factory Acceptance Testing
Every transformer undergoes 100% routine quality testing prior to international shipment.
Routine Factory Testing
Winding resistance, voltage ratio, phase displacement vector group check, separate-source AC withstand voltage, short-time overvoltage, no-load loss, and load loss measurements.
Dielectric & Oil Quality Analysis
Insulation resistance (Megger) evaluation and breakdown voltage (BDV) testing of mineral insulating oil to guarantee zero moisture contamination.
Type & Special Testing Capability
Third-party NABL laboratory certified type tests including Lightning Impulse Voltage Withstand test, Temperature Rise test, and Short-Circuit Withstand verification.
Export-Grade Seaworthy Packaging
Heavy-duty wooden crate packaging with moisture-barrier wrapping and rust inhibitors, ensuring safe transit for containerized ocean freight worldwide.
Request Technical Data Sheets & Quotations
Partner with an experienced ISO 9001 certified transformer manufacturer for your utility tenders, infrastructure development, or industrial plant installations.