HT instruments SPEED418 User Manual
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