Switzerland – Installation services of transformers – 6 piece regulating transformers 40MVA ONAN (50MVA ONAF) 110//10/20kV

The supply, installation and commissioning of six on-load tap-changer (OLTC) transformers, 110kV, with primary voltage switchable from 10kV to 20kV, with an apparent power of 40MVA ONAN, respectively 50MVA ONAF. Both the high voltage (HV) and low voltage (LV) windings are permanently rated for 50MVA. Operation is envisaged without forced cooling up to 40MVA, above 40MVA the OLTC transformer must automatically switch on the forced cooling. Purpose of the OLTC transformer, with tertiary winding for voltage regulation. Operating mode continuous duty. Design power transformer with primary side tap changer, low voltage switchable from 10kV to 20kV. Type oil-immersed transformer with air bushings on both the LV and HV sides for outdoor installation or twice indoor installation and road transportable version for delivery. Expected lifetime 60 years