Toshiba Cv-6ha , Contactor Magnetic, Ctry.mfg Toshiba Part Cv-6ha, 100-110 V Ac/dc, 50/60 Hz, 7.2 Kv, 6.6-3.3 Kv Operational Voltage, 400a, Draw-out Type, Vacuum Contactor With Clf Fuse. The Toshiba HCV-6KAU and HCV-6KALU vacuum contactors described in this manual are suitable for use on systems of 7.2kV 720A 7.2kA. Arc interruption is accomplished inside sealed vacuum interrupters mounted on track-resistant insulators. Vacuum interrupters use low-surge contact materials, which exhibit low current chopping levels reducing switching over-voltage.