Abstract: A ground fault detection system is taught which may be utilized on delta or wye connected polyphase electrical systems. The presence of a ground fault causes the neutral to ground voltage of a wye connected electrical system to increase to some value other than zero. Since a delta power system can be interconnected with a wye monitoring system to create an artifical neutral, a ground fault detector and pulsing arrangement can be provided between ground and the appropriate monitoring neutral. This system includes a coil which actuates a relay system which causes a first resistor to be alternately connected into and disconnected out of the ground current return path. The connection is made in parallel with a fixed resistor. This causes a change in the value of ground fault current with a given periodicity and frequency which in turn induces electromagnetic radiation around that path through which the ground fault current flows.