Higher rated circuits has a much lower R1+R2, producing voltage drop on the transformer and in turn a lower touch voltage whereby disconnection can be longer without worry of physiological harm.
I think this was discussed before, and I still think that's a dangerous assumption. Take a typical 63A BS 88-3/BS1361 fuse (commonly used for distribution circuits in domestics) - Max Zs for 5s is 0.68Ω so fault currents could be as low as 338A - is that sort of additional load really going to collapse the output of a public supply transformer?
Higher rated circuits has a much lower R1+R2, producing voltage drop on the transformer and in turn a lower touch voltage whereby disconnection can be longer without worry of physiological harm.
I think this was discussed before, and I still think that's a dangerous assumption. Take a typical 63A BS 88-3/BS1361 fuse (commonly used for distribution circuits in domestics) - Max Zs for 5s is 0.68Ω so fault currents could be as low as 338A - is that sort of additional load really going to collapse the output of a public supply transformer?
