水線(bonding)打圈有乜用?

通常水線bonding打圈是在一些活動位才會,
例如電箱的接地和電箱的門,鐵門和門框的接地線,使到接地連續性良好,
開關門時水線bonding打圈就會不易拉断水線
至於RCD後條N線打圈是沒作用的.

For extend use propose, because most of this bonding case were installed on moveable metallic parts (e.g. metal door), so this design can provide a flexible distance movements to the bonding cable.