Down conductors
Down conductors should within the bounds of
practical constraints take the most direct
route from the air termination system the earth
termination system. This statement
is reinforced within the 2011 version of
IEC/BS 62305, being incorporated the
body the standard, rather than forming part of
an Annex (Annex IEC/BS 62305-3:2006).
—
Table Minimum thickness metal sheets metal pipes
in air termination systems (IEC/BS 62305-3 Table 3). The down
conductor spacing should correspond with the
relevant class LPS. The greater the number of
down conductors the better the lightning current
is shared between them.5 mm
Copper 0.—
Technical reference
IEC/BS 62305-3 Physical damage to
structures life hazard
Non-conventional air termination systems
A lot technical (and commercial) debate has
raged over the years regarding the validity the
claims made the proponents such systems.7 mm
(1)
Thickness prevents puncture, hot spot ignition.
Typically the air rod tall then the only
claim for the zone protection afforded this
air rod would based and the relevant
class LPS and not any enhanced dimension
claimed some nonconventional air rods.
(2)
Thickness only for metal sheets not important prevent
puncture, hot spot ignition problems.
Lateral connections sometimes referred as
coronal bands ring conductors provided either
by fortuitous metalwork external conductors
at regular intervals are also encouraged. air rod) shall be
determined only the real physical dimension
of the air termination system. Down conductors should wherever
possible installed each exposed corner of
the structure research has shown these carry
the major part the lightning current. This enhanced further
by equipotential bonding the conductive
parts the structure.g.
Natural components
When metallic roofs are being considered a
natural air termination arrangement, IEC/BS EN
62305 offers guidance the minimum thickness
and type material under consideration, well
as additional information the roof has be
considered puncture proof from lightning
discharge (see Table 6).
Class LPS Material Thickness(1)
t Thickness(2)
t’
I Lead 2.5 mm
Aluminium 0.
This topic was discussed extensively within the
technical working groups that compiled
IEC/BS 62305.
IEC/BS 62305 states unequivocally that the
volume zone protection afforded the
air termination system (e. The outcome was remain with
the information housed within this standard.5 mm
Titanium 0.
There should always minimum two down
conductors distributed around the perimeter of
the structure.65 mm
Zinc 0.
112 FURSE® EARTHING LIGHTNING PROTECTION
QUALIT SOLUTIONS FOR SAFEGUARDING PEOPLE, STRUCTURES AND SERVICES
.0 mm
Steel
(stainless,
galvanized)
4 0.
There other standard being contemplated to
run parallel with this standard IEC/BS 62305
