Ground or Earth fault protection Relay - RCB, RCD

Connection types of Ground / Earth fault protection

In star point of an over current relay -

                           Fig: Ground fault relay connection in star point of over current relay

In Secondary of a ring type Current transformer

                   Fig: Ground fault relay connected to secondary of ring type current transformer

In neutral point of a Generator, Power Transformer, Motor

Fig: Ground fault relay connected to star point of power transformer or a Generator / or a motor