A.Founded in1980 B.CE,ROHS,SGS,UL,KEMA,VDE,TSE,CB C.ISO9001,14001 D.manufacturer E. 430 employees,15000 square meter ... This indicator is designed for easy testing of phase sequence In three-phase systems with a permissible operating voltage up to 500V.For short ... connections, not longer than 5 minutes for one test, a push ...