3
Original Case
IEC 62305-2 [2010] Example E3 - Office building
true
false
false
false
As a second case study, an office building with an archive, offices and a computer centre is considered (Figure E.2).
Loss of human life (L1) and economic loss (L4) are relevant for this type of structure.
It is required to evaluate the need for protection. This implies the determination of only the risk R1 for loss of human life (L1) with the risk components RA, RB, RU and RV (according to Table 2) and to compare it with the tolerable risk RT = 10–5 (according to Table 4). Suitable protection measures will be selected to reduce the risk to or below the tolerable risk.
Following the decision taken by the owner an economic evaluation is not requested; therefore the risk R4 for economic loss (L4) is not considered.
0
4
500
0
1
Primary Structure
0
20
40
25
0
2
1
0
0
1
0
L1 - Power line
0
0
1
0
0
2
0
0
LS1
0
0
200
0
1
1
-1
0
0
0
1
2.5
1
0
0.2
L2 - Telecom line
1
0
0
0
0
1
0
0
LS1
1
0
1000
0
0.5
1
-1
0
0
0
1
1.5
1
0
1
Z1 - Entrance area
1
2
0
0
0
0.001
0
1
0
0
0
0
1
0
0
4
8760
7
24
52
1
0.01
0
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z2 - Garden (outside)
1
0
0
0
0
0.01
0
1
0
0
0
0
1
0
0
2
8760
7
24
52
1
0.01
0
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
true
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z3 - Archive
0
7
4
0
0
1E-05
0.1
1
0
0
0
1
1
3
0
20
8760
7
24
52
2
0.01
0.02
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z4 - Offices
0
7
6
0
0
1E-05
0.001
1
0
0
0
1
1
3
0
160
8760
7
24
52
2
0.01
0.02
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z5 - Computer centre
0
7
6
0
0
1E-05
0.001
1
0
0
0
1
1
3
0
14
8760
7
24
52
2
0.01
0.02
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0.001
0.001
0.001
0
-1
Solution A
IEC 62305-2 [2010] Example E3 - Office building
true
false
false
false
The risk R1 in the structure is mainly concentrated in zone Z3 due to physical damages caused by lightning striking the structure or the connected lines (components RB ≈ 49 % and RV ≈ 50 % together cover 99 % of the total risk) (see Table E.20).
These dominant risk components can be reduced by:
providing the whole building with an LPS conforming to EN 62305-3 reducing component RB via probability PB. Lightning equipotential bonding at the entrance – a mandatory requirement of the LPS - reduces also the components RU and RV via probability PEB,
providing zone Z3 (archive) with protection measures against the consequences of fire (such as extinguishers, automatic fire detection system etc.). This will reduce the components RB and RV via the reduction factor rp,
providing lightning equipotential bonding conforming to EN 62305-3 at the entrance of the building. This will reduce only the components RU and RV via probability PEB.
Combining different elements of these protective measures the following solution could be adopted:
protect the building with a Class III LPS conforming to EN 62305-3, to reduce component RB (PB = 0,1); this LPS includes the mandatory lightning equipotential bonding at the entrance with SPDs designed for LPL III (PEB = 0,05) and reduces components RU and RV.
0
4
500
0
1
Primary Structure
0
20
40
25
0
2
1
0
0
1
0
L1 - Power line
0
0
1
2
0
2
0
0
LS1
0
0
200
0
1
1
-1
0
0
0
0.05
2.5
1
0
0.2
L2 - Telecom line
1
0
0
2
0
1
0
0
LS1
1
0
1000
0
0.5
1
-1
0
0
0
0.05
1.5
1
0
1
Z1 - Entrance area
1
2
0
0
0
0.001
0
1
0
0
0
0
1
0
0
4
8760
7
24
52
1
0.01
0
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z2 - Garden (outside)
1
0
0
0
0
0.01
0
1
0
0
0
0
1
0
0
2
8760
7
24
52
1
0.01
0
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
true
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z3 - Archive
0
7
4
0
0
1E-05
0.1
1
0
0
0
1
1
3
0
20
8760
7
24
52
2
0.01
0.02
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z4 - Offices
0
7
6
0
0
1E-05
0.001
1
0
0
0
1
1
3
0
160
8760
7
24
52
2
0.01
0.02
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z5 - Computer centre
0
7
6
0
0
1E-05
0.001
1
0
0
0
1
1
3
0
14
8760
7
24
52
2
0.01
0.02
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0.1
0
0.001
0.001
0.001
0
-1
Solution B
IEC 62305-2 [2010] Example E3 - Office building
true
false
false
false
The risk R1 in the structure is mainly concentrated in zone Z3 due to physical damages caused by lightning striking the structure or the connected lines (components RB ≈ 49 % and RV ≈ 50 % together cover 99 % of the total risk) (see Table E.20).
These dominant risk components can be reduced by:
providing the whole building with an LPS conforming to EN 62305-3 reducing component RB via probability PB. Lightning equipotential bonding at the entrance – a mandatory requirement of the LPS - reduces also the components RU and RV via probability PEB,
providing zone Z3 (archive) with protection measures against the consequences of fire (such as extinguishers, automatic fire detection system etc.). This will reduce the components RB and RV via the reduction factor rp,
providing lightning equipotential bonding conforming to EN 62305-3 at the entrance of the building. This will reduce only the components RU and RV via probability PEB.
Combining different elements of these protective measures the following solution could be adopted:
protect the building with a Class IV LPS conforming to EN 62305-3, to reduce component RB (PB = 0,2); this LPS includes the mandatory lightning equipotential bonding at the entrance with SPDs designed for LPL IV (PEB = 0,05) and reduces components RU and RV;
use fire extinguishing (or detection) systems to reduce components RB and RV. Install a manual system in the zone Z3 (archive) (rp = 0,5).
0
4
500
0
1
Primary Structure
0
20
40
25
0
2
1
0
0
1
0
L1 - Power line
0
0
1
1
0
2
0
0
LS1
0
0
200
0
1
1
-1
0
0
0
0.05
2.5
1
0
0.2
L2 - Telecom line
1
0
0
1
0
1
0
0
LS1
1
0
1000
0
0.5
1
-1
0
0
0
0.05
1.5
1
0
1
Z1 - Entrance area
1
2
0
0
0
0.001
0
1
0
0
0
0
1
0
0
4
8760
7
24
52
1
0.01
0
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z2 - Garden (outside)
1
0
0
0
0
0.01
0
1
0
0
0
0
1
0
0
2
8760
7
24
52
1
0.01
0
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
true
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z3 - Archive
0
7
4
1
0
1E-05
0.1
1
0
0
0
1
1
3
0
20
8760
7
24
52
2
0.01
0.02
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z4 - Offices
0
7
6
0
0
1E-05
0.001
1
0
0
0
1
1
3
0
160
8760
7
24
52
2
0.01
0.02
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Z5 - Computer centre
0
7
6
0
0
1E-05
0.001
1
0
0
0
1
1
3
0
14
8760
7
24
52
2
0.01
0.02
0
0
0
0
false
0
0
0
false
0
0
0
0
0
0
0
0
0
0
1
0
0
0
false
false
false
false
false
false
false
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0.2
0
0.001
0.001
0.001
0
-1
EN 62305:2010 Annex E Examples
A. N. Other Contracting
1234 A. N. Other Street
A. N. Other Town
A. N. Other county
ANOT HER
[Annex NE Examples]
NA
The following calculation is taken from Annex E of NF EN 62305-2:2010
The example was based upon the equivalent example contained within IEC 62305-2:2010
A. N. Other