On-Load Tap Changer (OLTC)

Sei is the exclusive representative in Latin America for Hyundai Heavy Industries Bulgaria for the On-Load Tap Changers. Hyundai entered the OLTC market by acquiring Elprom, a company manufacturing OLTCs since 1952 in Bulgaria. Hyundai’s OLTC are designed up to 300kV and can be supplied with vacuum, SF6 or oil technology. The OLTCs are engineered to meet the highest operational seismic and short circuit requirements. Type tests are performed by recognized labs such as KEMA and CESI.

Hyundai’s OLTC are designed up to 300kV and can be supplied with vacuum, SF6 or oil technology. The OLTCs are engineered to meet the highest operational seismic and short circuit requirements. Type tests are performed by recognized labs such as KEMA and CESI.

RS 21 SERIES
    Rated currents (A):
  • 310 – single phase design
    Rated voltage (kV):
  • 72,5
    Step voltage (V):
  • 1200
    Connection diagrams:
  • reverse change-over selector
    Number of steps:
  • up to 23
    Selector switch insulation level:
  • L
    Carrying flange shape:
  • Ellipti
RS 5 AND RS 5.3 SERIES
    Rated currents (A):
  • 200, 400, 630 and 1250 - three phase design for delta connected windings
    Rated voltage (kV)
  • 41,5 and 72,5 - full insulation between phases of delta connected windings
    Step voltage (V)
  • up to 3000
    Connection diagrams:
  • with and without coarse and reverse change-over selector
    Number of steps:
  • up to 27
    Selector switch insulation level:
  • K and L
    Carrying flange shape:
  • round or elliptic
RS 6 AND RS 6.3 SERIES
    Rated currents (A):
  • up to 1250 - three phase design for regulation at neutral point
    Rated voltage (kV):
  • 41.5; 72.5; 123; 170; 245 and 300
    Step voltage (V):
  • up to 2500
    Connection diagrams:
  • with and without coarse and reverse change-over selector
    Number of steps:
  • up to 27
    Selector switch insulation level:
  • K, L and M
    Carrying flange shape:
  • round or elliptic
RS 7.3 SERIES
    Rated currents (A):
  • 200, 400, 630 and 800 - single phase design
    Rated voltage (kV):
  • 41,5; 72,5; 123;170 and 245 - single phase design
    Regulation schemes:
  • with multiple change-over selectors
    Number of steps:
  • up to 125
    Selector switch insulation level:
  • L, M, N for single phase execution
    Carrying flange shape:
  • round
RS 9 AND RS 9.3 SERIES
    Rated currents (A):
  • 200, 400, 630 - three phase design for regulation at neutral point
  • 200, 400, 630, 800, 1200 and 1600 - single phase design for all connection diagrams
    Rated voltage (kV):
  • 41,5; 72,5; 123; 170; 245 and 300
    Step voltage (V):
  • up to 4000
    Connection diagrams:
  • with and without coarse and reverse change-over selector
    Number of steps:
  • up to 35
    Selector switch insulation level:
  • K, L, M, N and P
    Carrying flange shape:
  • round or elliptic
RS 12 SERIES
    Rated currents (A):
  • 200, 400, 600
    Rated voltage (kV):
  • 41,5; 72,5 and 145
    Step voltage (V):
  • up to 2000
    Electrical endurance
  • 800 000 s.o.
    Switching operations till inspection:
  • 300 000 s.o.
    Number of steps:
  • over selector 12/23
    Carrying flange shape:
  • over selector 12/23