HT 400 Series, Руководство пользователя

Страница: 5 / 88

400 Series
EN - 3
13.7. Fault loop impedance measurement ............................................................................... 78
13.7.1. Purpose of the test ................................................................................................................. 78
13.7.2. Installation parts to be checked ............................................................................................. 78
13.7.3. Allowable values .................................................................................................................... 78
13.8. Earth resistance measurementin TT systems ................................................................. 79
13.8.1. Purpose of the test ................................................................................................................. 79
13.8.2. Installation parts to be checked ............................................................................................. 79
13.8.3. Allowable values .................................................................................................................... 79
13.9. Voltage and current Harmonics ....................................................................................... 80
13.9.1. Theory .................................................................................................................................... 80
13.9.2. Limit values for harmonics ..................................................................................................... 80
13.9.3. Presence of harmonics: causes ............................................................................................. 81
13.9.4. Presence of harmonics: consequences ................................................................................. 82
13.10. Power and Power Factor definition ................................................................................. 82
13.10.1. Note ........................................................................................................................................ 83
13.10.2. Conventions on powers and power factors ........................................................................... 83