process frame (in industrial install.), cables, etc.
2b
1a Voltage drop at the surge earth resistance Rst
2a
1b Induced voltages in loops
1 L1 L2 L3 PEN
20 kV
Structure 2
Telecom. cable
i1
S341
U1
some 100kV
i2
U2
0V
341e.ppt / 04.09.97
Impulse Sparkover/Puncture Voltages in Electr. Systems and Equipment up to 1000 V
2c Fields of lightning channel
535e.ppt / 04.09.97
Calculation of lightning voltage
Prot. Level Current Amplit. kA
i
I
200
II
150
î
III - IV
100
Lit.: IEC 61024-1-1
EBB
PS
External LPS
Water Gas
Cathodic protection of filler pipe
S532/3e
Z
Foundation earth electrode
532-3e.ppt / 08.09.97
Standardization in IEC TC 81
Standard IEC 61312 "Protection against lightning electromagnetic impulses (LEMP)"
Devices
Part 4: LEMP for existing structures
Part 5: Application
Guide
S877e_c
877e / 10.09.97
Screening factor Sf Magnetic screen attenuation (dB)
d
Magnetic Screen Attenuation of
V
10
110
20
1
1100
200
0.1
11000
Source: Clark, O.; Gavender, R. : Lightning Protection for Microprocessor based Electronic Systems. Recond of Conference Papers Industrial Applications Society, 36th Annual Petroleum and Chemical Industriy Conference 11-13 Sept. 1989, San Diego, CA, USA
ûE = î·Rst
t Waveform 10/350 µs
Example:
Rst ûE = 100 kA ·1 = 100 kV
S88e
88e.ppt / 04.09.97
Voltages due to lightning inside a building
100 kA
230 V
S1500e
Standardization in IEC TC 81 in November 1996
IEC TC 81
"Lightning Protection"
IEC 61024
"Protection of structures against lightning"
IEC 61312
"Protection against lightning electromagnetic impulses (LEMP)"
230 V
100 kV 100 kV
100 kV 1
1500e.ppt / 04.09.97
A Direct Lightning Stroke into Structure 1 Causes Damage due to Overvoltages in Structures 1 and 2
i
Structure 1
some kA some
230 V~ some kA
Water / Gas some kA
553e.ppt / 26.10.98 / ESC
ûs
S91/1e_a
Maximum Induced Voltages in Installation Loops
Max. Voltage
ûs
=
ku2
·
Dangerous Surges in Neighbouring Buildings
some 100 kA
some 10 kV
some 100 kV
some 10 kV 230V OV
Telecomm. Line
some kA
some 10 kA
some
553e
some kA
some
some 10 kA
Max. Voltage
ûs
=
ku3
·l
·

di dt

max.
b
ûs
l
s
Calculation Example
(di / dt) max. Distances
100 kA/µs s l ku3
b = 3 mm
= 1m
= 10 m
V
= 0.6 m ·kA/µs
ûs 600 V
91-1e.ppt / 04.09.97
1000
60
316
50
100
40
31.6
30
10
20
w
3.16
10
w = 12 mm d = 2 mm
w = 10 cm d = 12 mm
w = 20 cm d = 18 mm
w = 40 cm d = 25 mm
w = mesh width d = rod diameter
1
S761e
0
102 3
Equipment / Cables / Conductors
Impulse Sparkover/ Puncture Voltages
Longituninal volt. UL Electrical power units to enclosure/
ground
Telecommunications equipment
Integrated circuits , bipolar technique high level HTTL and operation amplifiers
Integrated circuits, MOS technique
5 ... 8 kV 1 ... 3 kV 0.5 ... 5 kV
6 ... 100 V *) 3 ... 300 V *)
di dt

max.
s a
Calculation Example
(di / dt) max. Distances
100 kA/µs s ku2
a = 10 m = 1m = 5000
V kA/µs
ûs 500 kV
91-1e.ppt / 04.09.97
S91/1e_b
Maximum Induced Voltages in Installation Loops
103
3 104
3
105
3 106 f
(Hz)
761e.ppt / 06.09.97
Reinf. Facade
Shielding of Structures
Concrete Structure
Insulating Support Ring Earth Electrode
Earthing Ref. Point Ground Plate
Causes and Effects of Overvoltages 雷击过电压的危害与预防
Causes of Thunderstorm Overvoltages
Direct/nearby stroke:
1 Stroke into external lightning protection system,
Reinforcing Steel
S665e
665e.ppt / 09.09.97
ROOF UF LF
Bonding of Roof Structures
Direct bonding
Bonding via spark gap
Transverse volt. Uq between the
of electronic equipment / circuits
Circuits with discrete components (resistances, capacitors etc.) input terminals Integrated circuits, bipolar technique (TTL)
2000
S738e
738e.ppt / 05.09.97
Surge Voltage Produced by Switching on a Fluorescent Tube
50 V div
2 µs div
S701e
701e.ppt / 05.09.97