This standard is applicable to devices for surge protection against indirect and direct effects of lighting or other transient overvoltages these devices are packaged to be connected to 50/60 Hz a.c (Published Document (JS))
This part of JS 61557 specifies requirements for combined performance measuring and monitoring devices that measure and monitor the electrical parameters within electrical distribution systems. These requirements also define the performance, in single and threephase a.c. or d.c. systems having rated voltages up to 1 000 V a.c. or up to 1 500 V d.c. (Published Document (JS))