Heavy-Duty Oil Cooled Transformers (63 KVA to 5000 KVA up to 33kV)
At Chetan Electric Pvt. Ltd., we specialize in the design, engineering, and precision manufacturing of high-reliability Oil Cooled Transformers tailored for global power utilities, industrial manufacturing facilities, commercial complexes, and infrastructure projects. Established in 1994, our engineering facility produces custom-built oil Immersed power and distribution transformers strictly compliant with IS 2026, IS 1180, and IEC 60076 international quality benchmarks.
Our oil cooled transformers utilize prime-grade Cold Rolled Grain Oriented (CRGO) silicon steel cores, high-purity electrolytic copper/aluminum conductors, and premium-grade mineral insulating oil (per IS 335 / IEC 60296). Designed for continuous full-load operation under severe ambient conditions, each unit delivers superior thermal dissipation, minimized load/no-load losses, and prolonged operational lifespan exceeding 30 years.
Technical Specifications & Design Parameters
Every transformer built by Chetan Electric undergoes rigorous thermal modeling and electromagnetic design optimization to ensure maximum electrical efficiency and low noise emission.
| Parameter | Standard Specifications |
|---|---|
| Power Capacity Range | 63 KVA to 5000 KVA (Custom Ratings Available) |
| Primary Voltage Class | 11 kV, 22 kV, 33 kV (3-Phase, 50Hz / 60Hz) |
| Cooling Mechanism | ONAN (Oil Natural Air Natural) / ONAF (Oil Natural Air Forced) |
| Insulating Oil Standard | High Dielectric Mineral Oil per IS 335 / IEC 60296 |
| Temperature Rise Limit | 50°C in Top Oil / 55°C in Winding (over 45°C ambient) |
| Voltage Tapping Range | Off-Circuit Tap Switch (OCTS) ±5% in steps of 2.5% or On-Load Tap Changer (OLTC) up to ±15% |
| Vector Group Configuration | Dyn11, Dyn5, Ynd11 (or as per project drawing requirements) |
| Protective Accessories | Buchholz Relay, OTI, WTI, Magnetic Oil Gauge (MOG), Pressure Relief Valve (PRV), Marshalling Box |
| Surface Coating / Finish | Anti-corrosion Polyurethane / Epoxy Paint (AD Grey Shade 632 / C4 Marine Grade optional) |
Key Engineering Features & Component Construction
1. Low-Loss CRGO Steel Core
Precision-mitered step-lap core assemblies using prime-grade, low-loss CRGO laminations minimize eddy current losses, stray flux, and acoustic noise levels.
2. High Dielectric Windings
Wound with high-conductivity Electrolytic Grade Copper or Aluminum wire wrapped in multi-layer thermally upgraded kraft paper for maximum short-circuit withstand capabilities.
3. Robust Tank & Radiators
Fabricated from high-tensile steel plates with automated MIG welding, shot-blasted to Sa 2.5 standard, and pressure-tested for zero oil leakage under extreme temperature fluctuations.
4. Advanced Voltage Regulation
Fitted with Off-Circuit Tap Changer or automatic On-Load Tap Changer (OLTC) paired with Remote Tap Changer Cubicle (RTCC) and Automatic Voltage Relay (AVR) for seamless voltage stability.
Quality Assurance & CPRI Type Testing Compliance
Demonstrating our commitment to world-class engineering reliability, Chetan Electric transformers have successfully passed complete type-testing protocols at the Central Power Research Institute (CPRI), Bangalore — an internationally recognized independent testing authority. Every single production unit undergoes 100% routine factory acceptance tests (FAT) in our fully equipped testing laboratory prior to dispatch:
- • Measurement of winding resistance & voltage vector relationship
- • Measurement of voltage ratio and phase displacement check
- • Impedance voltage, short-circuit impedance, and load loss measurement
- • Measurement of no-load loss and no-load current at rated voltage
- • Separate-source AC withstand voltage test & induced overvoltage withstand test
- • Insulation resistance test and breakdown voltage (BDV) check of insulating oil
Global Deployment & B2B Procurement Support
Chetan Electric supplies custom oil cooled power and distribution transformers to overseas EPC contractors, industrial buyers, commercial developers, and government utilities across global markets. We provide comprehensive technical documentation, third-party inspection support (SGS, Bureau Veritas, TUV), and export-grade seaworthy packaging.
Request Technical Proposal & Factory Price Quote
Contact our senior electrical design engineers today to discuss your project specifications, custom voltage tapping requirements, or bulk procurement orders.
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