K-Factor

The K FACTOR TRANSFORMER is an isolating transformer that can be loaded at 100% of load plus the harmonics load without overheating. The losses generated by the harmonics can be calculated by multiplying the K factor by the stray losses. The K FACTOR is derived from a mathematical formula, which states that the eddy current losses in a transformer will be increased in direct proportion to the sum of the percentage current at a given harmonic level multiplied by the square of the harmonic order.

Advantages

  • Prevent the overheating of the transformer by increasing the stray losses with a K factor.
  • Prevent neutral overheating by over sizing it at 200%.
  • More efficient.

Application

The K FACTOR TRANSFORMER is used for non-linear loads. With the arrival of computers, faxes, printers and variable speed drives within the modern day business centers and industry we encounter harmonic problems. These loads are very non-linear and cause a non-sinusoidal waveform rich in harmonics.

The harmonics of most concern are the 3rd, 5th and 7th, causing serious problems with electrical office equipment and with power distribution systems.

These harmonics cause the following conditions:

  • Overheating of the transformer : these harmonics increase the stray losses by a factor, better known as “K factor”, and these additional losses increase the temperature of the unit.
  • High current in the neutral wire of the secondary transformer due to the presence of tripling harmonics as the 3rd , 6th and 9th . In the worst situation this current can be as high as 200% of the nominal current.
  • Blowing of breakers or fuses at or below recommended current.

Tech Sections

Characteristics

  • Reduction of skin effects by using multiple conductors of thinner dimensions.
  • Copper winding.
  • Taps 2-3% FCAN, 2-3% FCBN.
  • Delta-Wye connection standart or Delta-Zig-Zag.
  • 150oC temperature rise.
  • Insulation class 220oC.
  • Enclosure type Nema 2, 3R and 4.
  • Proper axial height of the winding. (Less than 15% between the primary and secondary winding).
  • Low flux density in high grain oriented steels.
  • Oversize neutral (200%) conductor

Options

  • Electrostatic shields
  • Aluminium winding
  • 80oC and 115oC temperature rise
  • k Factor (K4, K13, K20 and K30)
  • Nema 3R and Nema 4.
  • 50 Hz
  • Electrostatic shields
  • Aluminium winding
  • 80oC and 115oC temperature rise
  • k Factor (K4, K13, K20 and K30)
  • Nema 3R and Nema 4.
  • 50 Hz