Grounding, Earthing, Lightning Protection
Guidelines for the Earthing System and Grounding System Scope of the grounding system The grounding system for an electrical system creates the connection to earth and must meet the following requirements: Discharge the voltage from touchable metallic system parts (chassis) to protect people from electric shocks Discharge over-currents from direct lightning strikes to earth Discharge induced currents from atmospheric discharges between two points of a power transmission line to earth EMC performance and guidelines for the grounding system
106
System
EMC performance
TT
ELCB for personnel safety is Conditionally suitable Between the ground connection of the required primary distribution network and the Surge arresters should be installed leakage current from the electrical (distributed over power system, that are caused by ground transmission lines) faults within the system. As with This type of network requires transient currents, potential difference corresponding measures for occurs due to the leakage current from devices with high leakage current devices. These transient currents can potential that are located behind the lead to faulty couplings or even faults ELCB in the outgoing direction within the system. A corrective measure here is a equipotential bonding conductor between the devices connected directly to earth. These measures basically convert the TT system into a TN-S system.
Guidelines for use
TN-C TN-C-S
Bad Ensure an unobstructed path for Because the functions and protective the PEN conductor when earth conductor are combined in TN-C expanding the system! and TN-C-S systems, current Because of the high current in the feedback occurs on the PEN PEN conductor this system is not conductors during normal operation. permitted in areas of particularly Current feedback from devices via the dangerous sources. PEN conductors can lead to faulty If devices with high total harmonic couplings. distortion are operated in a system, this type of system is not recommended.
33002439 10/2019
