Furse Earthing & lightning protection

| Kategorie: Katalog  |

Vydal: ABB s.r.o.

Strana 111 z 132

Vámi hledaný text obsahuje tato stránku dokumentu který není autorem určen k veřejnému šíření.

Jak získat tento dokument?






Poznámky redaktora
The air rods should spaced not more than m apart and strike plates are used an alternative, these should strategically placed over the roof area not more than apart.— 03 — 04 The mesh method IEC/BS 62305 lists four different air termination mesh sizes that are defined and correspond the relevant class LPS. Vertical air rods (finials) strike plates should mounted above the roof and connected to the conductor system beneath. — 03 Effect the height the reference plane on the protection angle — 04 Concealed air termination network — 05 Determination the protective angle (IEC/ BS 62305-3 Table 2) Concealed conductor Vertical air termination Down conductor — 05 Note Not applicable beyond the values marked with Only rolling sphere and mesh methods apply these cases Note the height air-termination above the reference plane the area protected Note The angle will not change for values below 2m h (m) Class LPS I III IV α° 80 60 40 20 0 2 60 111 TECHNICAL REFERENCE IEC/BS 62305-3 PHYSICAL DAMAGE STRUCTURES LIFE HAZARD . This method suitable where plain surfaces require protection the following conditions are met: • Air termination conductors must positioned at roof edges, roof overhangs and the ridges of roof with pitch excess (5.7°) • metal installation protrudes above the air termination system Modern research lightning inflicted damage has shown that the edges and corners roofs are most susceptible damage. The IEC/BS 62305 Standard permits the use of conductors (whether they fortuitous metalwork dedicated conductors) under the roof. all structures particularly with flat roofs, perimeter conductors should installed close the outer edges the roof practicable