Dry Type Transformers

ADVANTAGES

  • Maintenance Free, Non Toxic
  • Non Inflammable, Non Hygroscopic
  • High Reliability, High Surge Voltage withstand
  • High Short Circuit Strength
  • High Overload Capacity
  • Low Partial Discharge
  • Smaller Size & Weight, Cost Effective
  • Low Noise Level & Weight, Cost Effective
  • Low Noise Level & Operating Cost

MAIN FEATURES

Dry Type Transformer Manufactures

  • Magnetic circuit: with CRGO lamination M3 to M5, MOH and ZDKH types
  • Electric circuit: copper 99.9% pure electric grade, foil for LV and strip for HV, duly casted with resin under vacuum
  • Dielectric circuits: Nomex glass fibre components along with resin casted components
  • Thermal Circuit: natural cooling through effective axial and radial ducts and air vent between LV to HV and LV to Core.

SPECIFIC FEATURES

  • Design conforms to relevant standards IEC 76, IEC 726, IS 11171, IS 2026 and as per any other international standards
  • Designed to withstand short circuit forces, thermal stresses and electrical impulses. Low partial discharge
  • Low load power losses and low noise
  • Fire retardant, compact and best suited for indoor installations
  • Installation can be very close to load centre thereby LT cable cost saving
  • Advanced manufacturing techniques to ensure cost effectiveness
  • Reliable, user friendly, easy to install and occupies less space

SPECIFICATIONS

  • Cast resin dry type transformer 11kV/433V, 3phase, 50 Hz
  • Off circuit tap links ± 5% in steps of 2.5%
  • Class F and H insulation
  • HV Delta connected, LV Star connected with Dyn 11 vector group
  • Natural air cooling and forced air cooling
  • Duty cycle – continuous
  • Winding material – copper
  • Enclosure – IP 23 to IP 33 and as per customer specifications
  • Cable boxes on HV and LV
  • Painting shades as per IS and IEC standards

STANDARD FITTINGS

  • Rating and diagram plate
  • Earthing terminals – 2
  • Off-circuit tap links
  • Enclosure – IP 23 with cooling louvers
  • Lifting lugs
  • Jacking lugs

OPTIONAL ACCESSORIES

  • PT-100 sensors in each coil
  • Winding temperature scanner with alarm and trip coil

INSPECTION AND TESTING

  • Incoming material inspection at vendors place
  • Stage inspections at end of each process
  • Identification and traceability

Final routine tests as per IS and IEC standards conducted as follows

  • Voltage ratio
  • Winding resistance
  • Impedance voltage
  • No load current with losses and load losses
  • Separate source voltage withstand test
  • Insulation measurement
  • Induced over voltage test
  • Noise level measurement