residual current devices;
earth fault loop impedance;
measurement;
D O I:
10.15199/48.2023.02.60
中图分类号:
TM [电工技术];
TN [电子技术、通信技术];
学科分类号:
0808 ;
0809 ;
摘要:
Measurement of the earth fault loop impedance in circuits with general-type residual current devices (RCDs) is problematic, because when using universal meters having a test current of 10-20 A, unwanted tripping of RCDs usually occurs. It is different in the case of circuits with time-delay type RCDs. This paper proves that the measurement can then be performed even with a high-current meter forcing a current with a peak value of about 200 A. The paper presents selected oscillograms of the test current and the results of the RCD's response during the measurement of the earth fault loop impedance.