Earthing Cable Size Calculator _verified_ 💎

The fundamental requirement for an earthing conductor is that it must survive the fault current without overheating or melting before the protective device operates.

The minimum required cross-section is 35 mm² (next standard size). earthing cable size calculator

A calculator would perform this instantly and often add a safety margin or round up to the nearest commercial cable size. The fundamental requirement for an earthing conductor is

A 415V industrial panel has a prospective earth fault current of 15 kA. The upstream MCCB trips in 0.1 seconds. The earthing conductor is copper with PVC insulation (k = 143). Find the minimum size. A 415V industrial panel has a prospective earth

: The operating time of the protective device (fuse or circuit breaker) in seconds (

When a "short circuit to earth" happens, massive amounts of current surge through the system. According to physics, current flow generates heat ($I^2Rt$). If the cross-sectional area of the cable is too small, the resistance is high, and the heat generated can exceed the thermal withstand capacity of the insulation or the conductor itself.