Engineered Efficiency
Precision laser-cut CRGO silicon steel cores minimize eddy current and no-load losses well below IEC 60076 standard requirements — reducing your operational energy costs over a 30-year service life.
Distribution Transformer Manufacturer Vietnam — SOTEK Group | IEC 60076 & IEEE C57 Certified
SOTEK Engineering Capabilities
Why Power Utilities Choose SOTEK
From CRGO core cutting and precision coil winding to vacuum drying and ISO-certified testing — every SOTEK transformer is engineered for grid resilience and long-term reliability.
Custom-Tailored Specifications
Low-sound residential designs, IEEE loop-feed padmount layouts, special DETC/OLTC tap changers, or biodegradable FR3 ester fluid — our R&D team engineers to your exact project parameters.
Type-Tested & Certified
Full type tests — lightning impulse, short-circuit withstand, and temperature rise — performed at our ISO/IEC 17025 (VILAS 1183) accredited laboratory. Complete FAT documentation provided for every shipment.
B2B Export Expertise
Supplying EVN-approved transformers to utilities in the Philippines (Aboitiz Power), Australia, Kenya, and Southeast Asia. FOB Hai Phong or CIF to any global port with full Incoterms support.
Modern Manufacturing Plant
18,500 m² Tien Son facility featuring Georg automatic core-cutting lines, automated layer winding, Hedrich vacuum casting chambers, and fully automated corrugated tank welding robots.
Full Compliance Documentation
ISO 9001:2015 & ISO 14001:2015 certified. Every batch ships with full technical dossiers including test reports, CAD drawings, material certificates, and IEC/IEEE compliance declarations.
Product Catalog · IEC 60076 & IEEE C57
Our Grid Integration Equipment
SOTEK supplies premium transformers tested to IEC 60076 and IEEE C57 standards for distribution, industrial, renewable energy, and underground grid applications.
Best Seller Liquid-Filled · IEC 60076
3-Phase Oil-Immersed Transformer
Hermetically sealed corrugated tank or conservator-type. Precision CRGO core, copper/aluminium windings. Designed for 22 kV / 35 kV medium-voltage distribution grids with high overload capacity.
50 – 21,000 kVA Up to 69 kV IEC 60076 ONAN / ONAF
Cast Resin · IEC 60076-11
Cast Resin Dry-Type Transformer
Vacuum-cast epoxy resin encapsulation. Class F & H insulation. Self-extinguishing, zero fluid leakage — ideal for commercial towers, hospitals, data centers, and underground substations.
50 – 6,300 kVA Class F / H Low Noise IP20 – IP23
New Line Underground Grid · IEEE C57.12.34
Padmount Transformer
Compartmentalized liquid-filled cabinet with separate HV/LV sections. Dead-front elbow connectors, Bay-O-Net fuse protection, loop-feed or radial-feed configurations for underground distribution.
75 – 5,000 kVA IEEE C57.12.34 ANSI C57.12.28 Dead-Front
Rural Electrification · ANSI C57.12.20
Single-Phase Pole-Mount Transformer
Compact overhead distribution transformers engineered for rural electrification and remote grid extensions. Withstands harsh coastal, tropical, and extreme weather environments.
15 – 500 kVA Up to 40.5 kV ANSI C57.12.20 50/60 Hz
Energy Saving Ultra-Low Loss · Amorphous Core
Amorphous Core Transformer
Fe-B-Si amorphous alloy core reduces no-load losses by 70–80% vs. conventional CRGO. Ideal for smart grids, solar/wind farms, and green building projects with 3–5 year ROI payback.
50 – 2,500 kVA 70–80% Loss Reduction IEC 60076
Renewable Energy · GSU / Step-Up
Step-Up Substation Transformer
Generator step-up (GSU) transformers for utility-scale solar PV and wind farms. Split-winding inverter integration, K-Factor harmonic rating, and biodegradable FR3 ester fluid options up to 35 kV.
Up to 21 MVA Up to 35 kV Split-Winding FR3 Option
International Certifications & QA Grid Compliance &
View Our Certifications
Grid Compliance &
Heavy-Duty Validation
Every SOTEK transformer is manufactured under rigorous QA/QC protocols aligned with ISO 9001:2015 and ISO 14001:2015. Our in-house ISO/IEC 17025 (VILAS 1183) accredited laboratory performs full type tests before shipment.
We provide complete technical dossiers including lightning impulse test records, short-circuit withstand reports, winding resistance measurements, and insulation resistance certificates — ensuring smooth approval with your local grid operator.
IEC 60076 — International Distribution Standard
IEEE C57 — North American & Philippine Utility Specs
ISO 9001:2015 & ISO 14001:2015 Certified
TCVN 6306 — Vietnamese National Grid Standard
EVN Approved Vendor — All 5 Regional Utilities
TÜV NORD
ISO 9001 System QA Audit
QUATEST 1
Independent Core Testing Lab
ASTA
Type Testing Compliant
EVN
Grid Approved Vendor · All Regions
VILAS 1183
ISO/IEC 17025 Accredited Lab
KEMA
Short-Circuit Type Test Certified
Technical Insights & Industry News
Grid Operations & SOTEK Updates
May 18, 2026
SOTEK Extends Supply Agreement with Aboitiz Power Philippines
Delivering IEC 60076 and ANSI-compliant distribution transformers to support grid modernization across Visayas and Mindanao utility networks — a milestone in SOTEK's Southeast Asia expansion.
Read Full Report →
April 27, 2026
Launching the IEEE Tamper-Resistant Padmount Series
SOTEK R&D completes full verification of modular loop-feed padmount transformers built to IEEE C57.12.34 and ANSI C57.12.28 tamper-proof enclosure standards for underground distribution networks.
Technical Details →
March 10, 2026
Gia Binh Factory Expansion Completes Phase 2 Testing
Scaling production capacity with positive-pressure clean rooms and new automatic vertical tension winding machines — tripling cast resin coil output for global demand up to 3,150 kVA / 35 kV.
Plant Tour →