Features Of Furnace Transformer

  • Electrostatic earth shield offered between primary and secondary side windings for secure protection of rectifier components against voltage surges in primary side windings. (Ref. D-2)
  • Utilize reduced current densities to limit losses due to harmonic currents.
  • Utilize reduced flux density to limit core losses due to harmonic flux.
  • Developed to suit 6 Pulse / 12 Pulse or other rectifier circuits as required by furnace manufacturer. Two active parts in one tank can also be provided.
  • Confirming to I.S. 2026 and I.S. 4540 - standards for power transformer and specifications for rectifiers.

Technical Specifications

TypeIndoor/ Outdoor Pad Mounted
DutyOn Load / Off Load
Voltage Class3.3, 6.6, 11, 22, 33 Kv or special class by customer
Vector GroupDyn11, Dyn5, Dyn1 or other specified by customer
No. of phase3 phases
Frequency50/60 Hz
Tap Range±10% in on load and ±7.5% in off load or other specified by customer.
Winding MaterialCopper with multiple paper covering
Applicable StandardsIS-2026, IEC 60076
PaintingEpoxy, Polyurethane or specified by customer

Why weight and dimensions of induction furnace transformers are higher than conventional transformer?

  • To achieve reduced current densities, more conductor cross-section areas are required, Hence core weight increases.
  • To achieve reduced flux density, more core cross-section are is required, hence core weight increases.
  • In a transformer, core weight and copper weight are inter dependent. Increase in conductor cross-section requires that core window is bigger resulting in the increase of core weight also. Similarly, an increase in core cross-section is achieved by increasing core dia. which increases mean Dias of winding and the lengths of their mean turn. This increases copper weight also, increase in core and copper weights increase the overall dimensions, increasing oil quantity, structural steel, etc.
  • When an electrostatic shield is provided between the windings, more radial gap is required between the windings. This further increase core weight, copper weight, oil quantity and structural steel.