Ht-instruments SPEED418 Manuel d'utilisateur télécharger pdf (Page 4)

400 Series

EN - 3

14.6.2. Installation parts to be checked ............................................................................................. 78

14.6.3. Allowable values .................................................................................................................... 78

14.7. Fault loop impedance measurement ............................................................................... 78

14.7.1. Purpose of the test ................................................................................................................. 78

14.7.2. Installation parts to be checked ............................................................................................. 78

14.7.3. Allowable values .................................................................................................................... 78

14.8. Earth resistance measurementin TT systems ................................................................. 79

14.8.1. Purpose of the test ................................................................................................................. 79

14.8.2. Installation parts to be checked ............................................................................................. 79

14.8.3. Allowable values .................................................................................................................... 79

14.9. Voltage and current Harmonics ....................................................................................... 80

14.9.1. Theory .................................................................................................................................... 80

14.9.2. Limit values for harmonics ..................................................................................................... 80

14.9.3. Presence of harmonics: causes ............................................................................................. 81

14.9.4. Presence of harmonics: consequences ................................................................................. 82

14.10. Power and Power Factor definition ................................................................................. 82

14.10.1. Note ........................................................................................................................................ 83

14.10.2. Conventions on powers and power factors ........................................................................... 83