What parameters are included in an oil filled transformer specification?

Parameters include rating, voltage ratio, frequency, vector group, impedance, insulation level, losses, temperature rise, cooling class such as ONAN or ONAF, and tap changer details. Oil related parameters include fluid type, total oil volume, tank design (sealed or conservator), breather, pressure relief, radiator and fan arrangement, and oil sampling points. Monitoring parameters include oil level indicator, top oil and winding temperature indicators, alarms, and optionally online sensors. The spec also defines testing, painting, sound limits, seismic requirements, containment expectations, and documentation deliverables.