... UL,KEMA,VDE,TSE,CB C.ISO9001,14001 D.manufacturer E. 430 employees,15000 square meter ... indicator is designed for easy testing of phase sequence In three-phase systems with a permissible operating voltage ... the direction of the arrow, if the three phases are properly connected, otherwise the disc ... direction .By changing of two wires, the phase sequence will be corrected to corresponding designation of ...