VSK with frequency inverter and SE-E5 Hermetic compact screw compressor VSK with frequency inverter, protection device SE-E5 (replaces SE-E5, fully exchangeable) and direct-on-line start Last revision of the diagram:17.04.2020 Technical documents for further information:SB-300: Operating instructions Hermetic compact screw compressors VSKCT-120: Protection devices for BITZER compressors