was looking at old fuse box and have:
main switch is cv1339-4
circuit breakers are bs3871
now im stumped no info for theses types of devices in regs, or am i missing something, quite old installation prob about 30 years how do i go about finding zs values for something like this?
main switch is cv1339-4
circuit breakers are bs3871
now im stumped no info for theses types of devices in regs, or am i missing something, quite old installation prob about 30 years how do i go about finding zs values for something like this?