1. Definition of terms
1) Lightning Protection (LP: Lightning Protection)
A complete system for protecting not only people but also structures, including internal systems and contents, from brain discharges,
Generally consists of LPS (Lightning Protection System) and SPM (LEMP Protection Measure)
2) Lightning Protection System (LPS)
A complete system used to reduce physical damage caused by lightning strikes to structures.
The lightning protection system consists of an external system and an internal system.
3) Lightning Protection Zone (LPZ)
Zone where the brain electromagnetic environment is defined
4) Lightning Protection Level (LPL: Lightning Protection Level)
A level determined by a set of lightning current parameters related to the probability of the maximum and minimum design values not exceeding naturally occurring lightning discharges.
LPL is used to design protection measures according to lightning current parameters.
5) LEMP Protection Measures (SPM)
Measures to protect internal systems from the effects of lightning electromagnetic impulses (LEMP)
2. Lightning protection zone (LPZ)
1) Area where the brain electromagnetic environment is defined
[Figure 1] Lightning protection zone classification
[Figure 2] Lightning protection zone concept diagram
2) Measures to protect the electrical and electronic equipment of a building from lightning surges include one or more of the following protective measures: grounding and bonding, magnetic shielding and surge inflow path shielding, SPD installation, and insulation interface configuration.
3) The space to be protected is divided into lightning protection zones (LPZ), which make areas of various risk values compatible with the strength of the electronic system and establish zones for equipotential bonding at the zone boundaries, and select protection measures accordingly.
4) The principle for dividing into different lightning protection zones is as shown in [Figure 1].
|
classification |
Justice |
Target equipment |
|
LPZ 0A |
○ Areas where there is a threat of lightning from direct lightning and general electromagnetic fields. ○ The internal system is susceptible to all or part of the lightning surge current flowing. |
○ Exterior lights (street lights, security lights) ○ Surveillance cameras, etc. |
|
LPZ 0B |
○ Areas protected from direct lightning strikes but subject to the overall threat of electromagnetic lightning fields ○ The internal system is prone to a portion of the lightning surge current flowing. |
○ Rooftop faucet (cubicle) facilities ○ Outdoor air conditioner ○ Aviation obstruction indicator ○ Antenna, etc. |
|
LPZ 01 |
○ Areas where surge currents are limited by current classification, insulation interface, or SPD in border areas ○ Spatial shielding is used to weaken the electromagnetic field caused by a lightning strike. |
Equipment at the entrance to the building (Water distribution equipment, MDF, telephone exchange, etc.)
|
|
LPZ 02 |
○ Areas where surge currents are limited by current classification in border areas, insulation interfaces, or the use of additional SPDs ○ Additional spatial shielding is used to further weaken the formation of brain electromagnetic fields. |
○ Disaster Prevention Center ○ Central Monitoring Room ○ Computer center, etc. |
[Figure 3] LPZ defined by LPS
6) Lightning protection areas are determined based on protection measures such as LPS, shielding lines, magnetic shielding, and SPD.
7) As a general principle for protection from lightning, the electromagnetic properties of the protected structure must be commensurate with the structure's ability to withstand the stress of the level of damage to be reduced (physical damage, failure of electrical and electronic systems due to overvoltage). Must be inside LPZ