400 kVA Dry Transformer

Overview: The 400 kVA Dry Transformer is designed for the modernization of the 6.3 kV and 20 kV CHE Scropoasa substation. This high-performance, three-phase transformer operates without protective casing and features a durable, maintenance-free construction, ideal for supplying 0.4 kV AC services in a 50 Hz environment.

Key Specifications:

• Power Rating: 400 kVA
• Voltages:
  • 6.3 kV Model: Primary 6.3 kV / Secondary 0.4 kV
  • 20 kV Model: Primary 20 kV / Secondary 0.4 kV
• Cooling System: Natural air circulation
• Temperature Class: According to SR EN 60076-3
• Maximum Winding Overtemperature: 100°C
• Noise Intensity: 63 dB
• Insulation: Epoxy resin and quartz powder blend for maintenance-free operation, moisture resistance, and fire safety.
• Core: Low-loss cold-rolled silicon steel with high magnetic permeability and low hysteresis and eddy current losses.
• Windings: Copper with epoxy resin insulation; high mechanical strength against short-circuit forces.

Technical Features:

• Connection: Dyn-5
• Adjustment: 5-step voltage adjustment with ±2x2.5% range on the high voltage side, performed in the absence of voltage.
• Insulation Level: F
• Environmental Conditions:
  • Maximum Ambient Temperature: +40°C
  • Minimum Ambient Temperature: -30°C
  • Altitude: <1200 meters
  • Humidity: <100% at 20°C
  • Seismicity: 760±15 mmHg

Accessories:

• Trolley: With bidirectional wheels and a wheel locking device
• Temperature Sensors: At least 3 PT100 
• Temperature Control Unit: Integrated into the protection, signaling, and monitoring system
• Lifting Lugs: For easy handling
• Neutral Terminal: Accessible on the low voltage side for the 400 kVA, 6.3/0.4 kV transformer

Compliance:

• Standards: EN 60076, CEI 60076 series, IEC 60185, DIN-VDE 0414-1
• ECO Design Directive: Compliant with 548/2014 and subsequent amendments

Operational Flexibility:

• Overload Capability:
  • 10% overload for 1 hour
  • 20% overload for 30 minutes
  • 30% overload for 15 minutes
  • 40% overload for 8 minutes
  • 50% overload for 4 minutes
• Overexcitation Tolerance: Capable of operating with a 5% maximum deviation from nominal voltage and frequency.

Testing

All transformers undergo rigorous factory testing, including:

• Verification of transformation ratio
• Connection group checking
• Winding resistance measurement
• Insulation resistance and absorption coefficient testing
• Dielectric loss angle tangent measurement
• Applied voltage and induced voltage tests
• Measurement of no-load and short-circuit losses
• Winding overheating and homopolar impedance measurement
• Noise level assessment
• Dielectric rigidity of the oil

For detailed information, technical queries, or to request a customized quote, please reach out to our dedicated sales team. We are committed to providing top-notch, reliable transformer solutions that meet your specific requirements. Contact us today to experience our exceptional service and expertise.