FURSE GUIDE TO BS EN 62305 PDF
Furse have now launched an updated Guide to BS EN Protection Against Lightning. This latest edition incorporates guidance on the. This handbook offers a guide for any designers of the structural Lightning protection system to comply with the requirements of BS EN range of standards. An overview of BS EN , its impact on lightning protection and the support and advice Earthing design considerations and full details of the Furse range of earthing materials .. illustrations and design examples, the Guide provides.
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The bonding conductor should have a direct connection to an earth bonding bar which in turn should be connected to the earth termination system.
A Guide to BS EN Protection Against Lightning_图文_百度文库
Earth electrodes in soil should be copper or stainless steel when they are connected to reinforcing steel embedded in concrete, to fuide any potential electrochemical corrosion. R1 risk of loss of human life R2 risk of loss of service to the public R3 risk of loss of cultural heritage R4 risk of loss of economic value Hereafter the primary risks will be referred to collectively as Rn where the subscript n indicates 1, 2, 3 or 4 as described above.
In reality, most structures have more than just one service connected as shown in Figure 5. For a three-phase 4 wire system, only 3. The LPZ concept as applied to the structure is illustrated in Figure 2.
Our interpretation of the lightning protection requirements can be 622305 by the flow chart shown in Figure 4.
It defines by its five annexes the lightning current parameters that are used to design and then select the appropriate protection ffurse detailed in the other parts. The spatial shield could also take the form of continuous metal — for example a metallic housing enclosing sensitive electronics. The risk process ro takes the designer through a series of calculations using dn formulae to determine the actual risk R for the structure under review. Typically, Annex A normative which discuss the positioning of the air rods finials states unequivocally that the volume or zone of protection afforded by the air termination system eg air rod shall be determined only by the real physical dimension of the air termination system.
Typically, add another section of earth rod to increase its length from 2.
Lightning Protection Standard BS EN 62305
This topic is covered in greater detail in Section 5 of this guide. In larger or extended structures several bonding bars may be required but they should all be interconnected with each other.
In addition the standard contains the following explicit statement that we believe applies to the UK: Shielding in subsequent inner LPZs can be accomplished by either adopting further spatial shielding measures, for example a screened room, or through the use of metal cabinets or enclosure of the equipment.
NO Calculate separation distance s Can separation distance be achieved?
Furse release 3rd edition of their renowned Guide to Lightning Protection
All metal pipes, power and data cables should, where possible, bx or leave the structure at the same point, so that it or its armouring can be bonded, directly or via equipotential bonding SPDs, to the main earth terminal at this single point.
Indeed, this also leads to downtime — the biggest cost to any industry.
In the case of overhead lines entering the structure, the physical dimensions of the lines are used to determine the effective collection area. Example of main equipotential bonding www.
The dimension for tape and stranded conductors fixed to horizontal surfaces should be 1,mm and not go stated mm. Other material used instead of copper should have cross-section ensuring equivalent resistance Table 5. Example of mesh air termination 37 www. Sometimes they re-enter the cloud base further ffurse, in which case they are regarded as cloudto-cloud discharges.
Only the passage of time will confirm this, or decide that it was a major advancement in our understanding of all the parameters needed to be addressed when evaluating the risk gudie lightning inflicted damage to humans, the structures they inhabit and the electrical systems they use. The term LEMP simply defines fursf overall electromagnetic effects of lightning that include conducted surges both transient overvoltages and transient currents as well as radiated electromagnetic field effects.
Similarly the loss of vital financial information for example that could not be passed onto clients of a Financial institution due to damage, degradation or disruption of internal IT hardware caused by lightning transients. If the overall earth reading is greater than 10 ohms then the length of the earth rod electrode should be increased by the addition of further sections to the extensible earth rod.
Furse release 3rd edition of their renowned Guide to
Particular attention should be paid to evidence of corrosion or yuide likely to lead to corrosion problems. How many metallic services are there entering or leaving the structure? These cable systems should not come into close proximity with lightning protection conductors, typically those located on or beneath the roof or on the side of structures equipment location will be discussed later in this guide.
L4 relates to the structure and its contents; to the service and the loss of activity, due to the loss. Each contains electronic equipment, which is connected to earth through its mains power supply. Normal mains power supply These destructive transient overvoltages can be conducted into electronic equipment by: At present three standards are published within the BS Ro series.