A coordination-free ground-fault relay for AC mine distribution systems

A brief review of the coordination-free, ground-fault-protection concept is presented, followed by a discussion of major design considerations. The actual design of a coordination-free relay system is then described along with laboratory test results. Based on experimental data, it is found that the coordination-free ground fault relay meets operational objectives. When tested with a commonly utilized ground check monitor, it was found that this system should be usable for projected cable lengths up to 4000 ft.<>