High impedance fault detection device tester

High impedance or down conductor fault detection devices are now commercially available for evaluation. However, security and dependability of these devices can not be tested using conventional relay test apparatus and procedures. This paper presents a test apparatus and procedures for testing high impedance fault detection devices. The apparatus is capable of playing back in real-time waveforms selected from a data library, which includes seventy seven field recordings of highimpedance faults and feeder loads. Each recording is approximately five minutes long and stored in the form of digitized data sampled at 20 kHz.