The LEP Superconducting RF system has reached its maximum configuration of 288 four-cell cavities powered by 36 klystrons in 1999. In 2000, this system, together with 56 cavities of the original copper RF system, routinely provided more than 3630 MV, allowing the beam energy to be raised up to 104.5 GeV. This has required not only operating the cavities more than 15% above their design gradient, but has also demanded a very high operational reliability from the entire system. Since 1995 energy upgrade from 45 GeV / beam with Superconducting cavities up to 104.5 GeV From 360 MV --> 3666 MV LEP circumference : 26.7 km, RF system in four straight sections one-cavity segment of module * 18 Power converter 100 kV / 40 A + 22 control racks in klystron tunnel RF Power Plant for SC cavities 8 cavities per klystron two 1.3 MW RF klystrons per 4 MW DC power supply Interlock trips lead to loss of accelerating voltage: RF trip: 8 cavites off, loss of about 100 MV ! High Voltage trip: 16 cavities off, loss of about 200 MV ! 1.3 MW cw klystron main cavity parameters