69kV 33kV 10MVA–30MVA ONAN Copper Oil Immersed Power Transformer for Substation Step Down
69kV / 33kV
Up to 30 MVA
IEC 60076
Distribution Transformer Technical Articles, Industry Insights & Grid Updates — SOTEK Group
Core Circuit Protection & Power Distribution Equipment
Customized high/medium voltage circuit breakers, cast-resin dry transformers, and oil-immersed substations tested to IEC 62271-100 and IEC 60076 standards for Istanbul’s power grid.
3-Phase Dry Type Isolation Transformer 100kva High Voltage Dry Type Industrial Transformer
100 kVA
Class F/H
Galvanic Isolation
YAWEI Factory Supply 10/11kV 500kVA–2500kVA Step Down Dry Type Transformer with Cooling Fan
11kV Step Down
2500 kVA Max
AF Forced Air
CE Certified 10kVA–50kVA 35kV to 380V 400V Step Down Three Phase Dry Type SMPS Transformer
35kV / 400V
CE Certified
Compact Footprint
Single Phase 6kV to 220V High Frequency Honeycomb Transformer Dry Type Isolation Custom Unit
6kV to 220V
Honeycomb Coil
Custom Winding
Three Phase Dry Type Transformer 50Hz/60Hz 10kV 35kV Cast Resin Transformer for Heavy Industry
10kV / 35kV
50Hz/60Hz Dual
Vacuum Cast
High Quality 630kVA High Voltage 20kV to 415V Low Loss Dry Type Power Transformer
630 kVA
20kV / 415V
Low Loss Core
DingXin SG IEC60076 ISO CE Certified Three Phase Dry Type Step Up/Down Isolation Transformer
440V Input
220V Output
ISO & CE
Grid Engineering Analysis
Istanbul & Marmara Grid Infrastructure: Technical Demand Dynamics
Istanbul, as the economic heart of Turkey spanning both the European (BEDAŞ grid network) and Asian (AYEDAŞ grid network) continents, presents one of the most complex high-voltage electrical distribution landscapes in the Mediterranean and Middle Eastern regions. Interconnected through the main transmission corridors operated by TEİAŞ (Türkiye Elektrik İletim A.Ş.), the Istanbul metropolitan power network demands circuit protection devices and step-down substation transformers capable of enduring exceptional electrical stress, rapid load variations, and strict thermal limits.
As a specialized high-voltage Circuit Breaker Manufacturer & Exporter for Istanbul, our engineering team manufactures medium-voltage (11kV, 33kV, 36kV) and high-voltage (up to 69kV and 110kV) Vacuum Circuit Breakers (VCB), SF6 Gas-Insulated Switchgear (GIS), Air Circuit Breakers (ACB), and accompanying cast-resin dry transformers. Our protection gear directly addresses the heavy electrification of Istanbul’s industrial parks (such as Gebze Organized Industrial Zone - GOSB, Dilovası, and İkitelli OSB), dense commercial skyscrapers in Maslak and Ataşehir (Istanbul Financial Center), and coastal maritime logistical hubs.
Key TEİAŞ & BEDAŞ Technical Requirements for Imports:
- Short-Circuit Breaking Capacity: Minimum 31.5kA to 50kA breaking ratings for 15s to withstand heavy grid fault surges.
- Seismic Rating: Qualification according to IEEE 693 / EN 60068-3-3 high-seismic level standards due to Marmara fault line proximity.
- Thermal Endurance: Class F and Class H insulation systems designed to handle summer peak urban heat islands without thermal tripping.
- Corrosion Protection: C5-M marine-grade powder coating for installations along the Bosphorus Strait and Tuzla shipyard coastline.
Equipment Specifications
Technical Performance Matrix: Circuit Breakers & Distribution Units
Engineering comparison of our exported medium and high-voltage circuit breakers, switchgear, and step-down distribution transformers designed for Turkish utilities.
| Equipment Type | Rated Voltage (kV) | Breaking / Interrupting Capacity | Insulation & Medium | Standard Compliance | Target Local Application in Istanbul |
|---|---|---|---|---|---|
| Indoor Vacuum Circuit Breaker (VCB) | 7.2kV – 36kV | 25kA / 31.5kA / 40kA | Vacuum Interrupter / Solid Epoxy | IEC 62271-100 / TSE | İkitelli OSB, BEDAŞ Urban Substations |
| Outdoor SF6 Gas Circuit Breaker | 33kV – 69kV | 31.5kA / 50kA | SF6 Gas Insulation | IEC 62271-100 / IEEE C57 | TEİAŞ Grid Step-Down Substations |
| Cast Resin Dry Transformer | 10kV – 35kV | 50kVA – 6,300kVA | Class F & H Epoxy Resin | IEC 60076-11 / CE | Istanbul Financial Center (İFM), Hospitals |
| Oil-Immersed Power Transformer | 33kV – 69kV | 10MVA – 30MVA ONAN | Mineral Oil / Copper Winding | IEC 60076 / ISO 9001 | Gebze Industrial Parks, Hydro & Solar Plants |
| Low Voltage Air Circuit Breaker (ACB) | 400V – 690V | 50kA / 65kA / 85kA | Air Break / Microprocessor Trip | IEC 60947-2 / CE | Ambarlı Port Logistics & Commercial Complexes |
Marmara Deployment Scenarios
Localized Application Scenarios Across Greater Istanbul
How our exported circuit breakers and integrated power transformers solve severe environmental and electrical challenges in key Marmara industrial sectors.
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1. Underground Metro & Rail Traction Lines
Istanbul’s rapidly expanding underground metro infrastructure (Metro Istanbul & Marmaray) demands rapid-arc-quenching circuit breakers and flame-retardant dry-type transformers. Our 35kV Vacuum Circuit Breakers (VCBs) and cast-resin units eliminate fire hazards in enclosed underground substations, ensuring uninterrupted 750V DC / 25kV AC traction power.
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2. Maritime & Shipyard Infrastructure (Tuzla & Ambarlı)
Shipyard cranes, shore-to-ship power connection facilities, and container handling terminals at Ambarlı Port operate in salt-laden coastal atmospheres. We supply circuit protection gear with C5-M anti-corrosion cabinet enclosures, anti-condensation heaters, and stainless-steel fasteners designed specifically for maritime humid environments.
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3. Heavy Manufacturing Hubs (Gebze & Dilovası OSB)
Heavy machinery, arc furnaces, and plastic injection plants in Gebze Organized Industrial Zone induce strong harmonic distortions and frequent load spikes. Our high-capacity 33kV step-down transformers paired with 40kA breaking capacity switchgear protect expensive industrial automation systems from line transients.
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4. High-Rise Commercial Hubs (İFM Ataşehir)
The newly developed Istanbul Financial Center (İFM) requires absolute power continuity and zero noise pollution. Our 100kVA to 2500kVA low-loss dry transformers featuring cooling fans and low-noise core stacking guarantee noise levels below 45dB while maintaining zero oil leakage risk inside high-rise basements.
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5. Thrace & Marmara Renewable Grid Extensions
Wind farms across the Thrace region and solar arrays in Marmara require step-up transformers and reclosers capable of handling bidirectional power flow. Our 69kV step-up substation transformers integrate seamlessly into green energy substations feeding into the national TEİAŞ grid.
Turkey Market Outlook
Industrial & Energy Transition Trends in the Marmara Region
Turkey’s official 2030 Energy Efficiency & Grid Modernization Strategy mandates the replacement of obsolete oil switchgear with environmentally benign vacuum and gas-insulated alternatives across all primary distribution nodes. The rapid transition toward smart grids, EV charging infrastructure along the O-4 highway corridor, and localized industrial self-generation has shifted procurement habits among Istanbul’s top electrical contractors (EPCs).
1. Shift to Eco-Friendly Dry Equipment
Urban municipalities in Istanbul strictly limit mineral-oil filled units inside residential and high-occupancy commercial zones due to fire risk, making cast-resin dry transformers mandatory.
2. Severe Earthquake Readiness
Following strict AFAD and TEİAŞ seismic directives, imported switchboards and circuit breakers must pass dynamic shake-table testing up to 0.5g ground acceleration without structural damage.
3. Digital Substation Integration
Modern procurement demands circuit breakers fitted with IEC 61850 compliant intelligent electronic devices (IEDs) for real-time SCADA monitoring and predictive maintenance.
Factory Competence & Quality Control
Why Leading Turkish Engineering & EPC Firms Partner With Us
Our state-of-the-art manufacturing campus operates under international ISO 9001:2015 and ISO 14001:2015 quality standards, deploying automated laser core-cutting and vacuum casting technology.
🔬 ISO/IEC 17025 Accredited Laboratory
Every batch of circuit breakers and transformers undergoes full Factory Acceptance Testing (FAT) — including lightning impulse, short-circuit withstand, partial discharge (<5 pC), and temperature rise verification.
⚙️ Precision CRGO & Vacuum Casting Tooling
Equipped with Georg (Germany) automated cut-to-length silicon steel core lines and Hedrich vacuum resin casting chambers, guaranteeing low no-load losses and long insulation life.
📜 Global Type-Test Certifications
Our transformer and switchgear series are fully verified by ASTA, KEMA, TÜV, and CE certification bodies, making local utility homologation in Turkey fast and friction-free.
🚢 Direct Export Logistics to Haydarpaşa & Ambarlı
Streamlined sea freight packaging with wooden ocean cases and sea-worthy moisture barrier vacuum bags, delivering FOB or CIF directly to major Turkish ports within optimal lead times.
Buyer Guidance
Procurement FAQ for Electrical Engineers in Istanbul
Answers to technical, regulatory, and logistics queries commonly raised by Turkish project managers and importers.
Are your exported circuit breakers compliant with TEİAŞ and BEDAŞ grid codes?
Yes. Our high and medium-voltage Vacuum Circuit Breakers (VCBs) and distribution transformers are engineered strictly per IEC 62271-100 and IEC 60076 standards. They meet the short-circuit withstand levels, impulse voltage requirements, and terminal connection layouts mandated by TEİAŞ and regional Turkish distribution companies.
What is the typical ocean freight transit time to Istanbul ports (Ambarlı / Haydarpaşa)?
Direct container shipping from our manufacturing facilities to Ambarlı Port or Haydarpaşa Port in Istanbul generally takes between 18 to 25 days depending on shipping line schedules. Full logistics support including Bill of Lading (B/L), CE declarations, and Certificate of Origin (COO) is provided.
Can you customize transformer secondary voltages to match 380V / 400V / 415V Turkish industrial standards?
Absolutely. We offer complete custom winding configurations. Input voltages (6kV, 10kV, 11kV, 20kV, 33kV, 35kV, or 69kV) can be stepped down to standard Turkish low-voltage distribution levels including 380V, 400V, 415V, or custom industrial taps with manual (DETC) or automatic under-load tap changers (OLTC).
How do your cast-resin dry transformers perform under high seismic conditions?
Our dry-type transformers feature monolithic glass-fiber reinforced epoxy resin encapsulation. The core and winding structures are anchored with heavy-duty structural steel frames designed to withstand seismic shaking up to Zone 1 severity (0.5g ground acceleration) compliant with IEEE 693 requirements.
Do you offer third-party inspection services before shipping?
Yes. We welcome third-party factory inspection agencies such as SGS, TÜV NORD, Intertek, or customer-appointed engineers to conduct live Factory Acceptance Testing (FAT) in our ISO 17025 accredited laboratory prior to container loading.
What warranty and technical support are provided for orders exported to Turkey?
All exported equipment comes with a standard 12-month to 24-month operational warranty backed by 24/7 remote engineering support. Replacement spare parts (such as vacuum interrupters, auxiliary switches, digital protection relays) can be dispatched rapidly via air freight to Istanbul.
Request Technical Specifications & B2B Export Quotation
Connect with our senior electrical engineering team to receive CAD drawings, type-test certificates, and competitive direct factory quotes for your project in Istanbul.