Lightning protection guide by OBO

| Kategorie: Katalog  |

Last revision 2020

Vydal: OBO BETTERMANN s. r. o. Autor: OBO BETTERMANN

Strana 182 z 288

Jak získat tento dokument?






Poznámky redaktora
Lightning strike 100% Iimp = max. 200 (IEC 62305) Earthing system 50% 100 (50%) Electrical installation 50% 100 (50%) Data cable (5%) Typical distribution lightning current TBS Blitzschutz-Leitfaden 2018 / en / 2020/01/10 14:42:40 14:42:40 (LLExport_02613) / 2020/01/10 14:42:54 14:42:54 182 Chapter The internal lightning protection system . Large surge voltages are coupled over ra- dius km.1 Lightning discharges (LEMP: Lightning Electro Magnetic Impulse) The international lightning protection standard IEC 62305 describes how direct lightning strikes to 200 are safely arrested. This then the potential difference between the local earth (equipotential bond- ing) and the active cables, which are earthed some distance away. Switching operations involving in- ductive loads create dangerous surge voltages the medium and low-voltage power networks. The highest surges are caused by lightning strikes. 3. Even from several hundred metres away, lightning currents can also cause impermissible surge voltages conductor loops, through either capacitive, inductive galvanic coupling.3 (starts 15).3.2. The voltage drop the earthing resistor calculated from the product the partial lightning current (i) and the earthing resistance (R). The current coupled in- to the earthing system and, due the voltage drop at the earthing resistor, half the lightning current is coupled into the internal installation. The partial light- ning current then divides itself among the power lines entering the building (number cores power line entering building), while around enters data cables. For further information types damage (S1–S4) see Chapter 1. According IEC 62305, lightning strikes are simu- lated with lightning surge currents of 200 (10/350 μs).2 Surge protection system for en- ergy systems Very large surge voltages are caused mainly light- ning strikes close energy systems