Products and Services – PT

Products and Services

Specifications

  • Rating: 28/40MVA
  • Voltage Ratio: 88/11kV
  • Tap changer: OLTC (on-load tap changer)
  • Cooling: ONAF (oil natural air forced)

Rating
Ratings up to 315MVA, complying with IEC 60076, BS 171 and SABS 780 specifications.

Voltage
All voltages up to and including 300kV.

Cooling
Oil immersed with natural or forced air cooling, ONAN/ONAF/ODAF.

Core
Three-limb boltless core constructed of cold rolled grain oriented steel with interleaved mitre cut joints.

Windings
Double or auto-wound, with tertiary if required. Rectangular copper, CTC paper insulated in the form of multi-layer disc or helix windings.

Tappings
For HV or LV voltage variation connected to off-circuit or on-load tap switches.

Tanks
Robustly constructed, with heavy gauge underbase and welded from high quality steel plate to withstand vacuum processing. Removable radiators with elliptical section cooling tubes connected to the tank via shut-off valves.

Painting and surface treatment
Prior to painting, the tank and related parts are shot blasted to grade SA 2,5 and external surfaces are treated with a rust preventative undercoat and two top coats of heavy duty outdoor oil paint. Special finishes for highly corrosive areas can be supplied if required.

Insulation
Oil impregnated high-grade electrical paper and pressboard. The windings are normally fully and uniformly insulated for lower voltages, and for the higher voltages partially graded or fully graded depending on the customer’s requirements.

Impulse level
All ratings have been tested for impulse withstand levels in accordance with IEC 60076.

Fittings and accessories
A full range of standard and special fittings is available and can be incorporated as required.

Terminals
Open type bushings for outdoor use or cable boxes as required.