Types of Short Circuit Faults

The most common type of short circuit in a three phase system is a single conductor to earth fault (Fig 1. Phase-to-earth). This is when one of the conductors in a circuit comes into contact with an earth.

下一个最常见的短路类型是与导体故障的相位或导体的相位（相位相位） - 当电路中的两个导体彼此接触时。

接下来是一个双相或双导体到接地故障（图3.相位 - 朝地） - 电路中的两个导体中的两个同时与地球接触。

And lastly, the least common type of short circuit is a balanced three phase or three conductor fault (Fig 4. Three-phase) – when all three conductors come into contact with an earth. Whilst this is uncommon, it can happen, and design engineers must go to considerable lengths to guard against the consequences of such an event.

In all cases these faults are short circuits – the path of least resistance is through a fault, and not through the equipment you are attempting to power.