Generic Design Data of KOLEKTOR ETRA TRANSFORMERS
Magnetic Laminations
- Materials:
- Conventional Oriented C.G.O. Class Laminations
- HI-B High Magnetic Orientation Steel Sheets
- Laser-Treated Magnetic Laminations
- Core Construction:
The magnetic core (available in 2, 3, or 5 legs) is constructed by stacking steel sheets. Laminations are secured using heat-shrink polyglass strips and anti-magnetic steel clamps, with varnish-glued lower yokes and limbs to minimize oscillations and vibrations caused by magnetostriction forces. - Frame Design:
The core is enclosed in a rigid frame with clamps and legs to ensure safe transportation and withstand short-circuit forces.
Windings
- Material: High-purity electrolytic copper (Cu-ETP).
- Design Specifications:
- Single- or multi-layer windings for phase currents up to 1,000 A and voltages up to 72.5 kV (245 kV for custom designs).
- Disc windings (helical, continuous, or interlaced) for higher voltage applications.
- Properties:
- Specific electrical conductivity: 58 Sm/mm² (10.0 MS/in²).
- Yield strength (Rp0.2): 90–160 N/mm² (13–23 ksi).
Thermal Insulation Classes
- Enamel Insulation (PVA): Thermal Class E (120°C/248°F), IEC 60317-0-2 compliant.
- Paper Insulation:
- Thermal Class A (105°C/221°F), IEC 554-3-5 compliant.
- Thermally Improved Paper, Thermal Class E (120°C/248°F), IEC 554-3-5 compliant.
Cooling Systems
- Designed per IEC 60076-7 and IEEE C57.12.00 standards.
- Configurations include radiators, oil coolers, and heat exchangers (OF and OD types only) with modular components for easy installation and maintenance.
- Cooling systems can be installed remotely and equipped with pumps for high-efficiency oil circulation and enhanced heat dissipation.
Heritage and Innovation
With a repository of over 4,000 transformer models, KOLEKTOR ETRA® blends decades of expertise with innovation, offering field-proven solutions tailored to demanding high-voltage applications in the U.S. and globally.
Testing and Standards
All transformers meet dual standards for compatibility with U.S. and international requirements:
- IEC 60076 / IEEE C57.12.90: Temperature rise, dielectric, short-circuit, and insulation tests.
- IEC 60354 / IEEE Loading Guide: Loading recommendations for oil-immersed transformers.
- NF C13-200 / NESC C2: Guidelines for installations with voltages >1 kV to ≤245 kV.
Assembly Inspections
Each core, winding, reservoir, and component undergoes rigorous inspections, including:
- Voltage ratio and interphase measurements.
- Insulation resistance testing.
- Short-circuit loss measurement before drying.
- Monitoring of transformer oil during the drying process.
Tailored for the U.S. Market
Through our US-ISATION program, we adapt our transformers to meet U.S. standards and industry needs:
- Imperial/Metric Dual Configuration: Components and systems available in imperial (lbs, inches, gallons) or metric (kg, mm, liters).
- Compliance: Fully compliant with U.S. IEEE, ANSI, and NESC standards, ensuring seamless integration into American infrastructure.
