BS EN 62305-1:2011 pdf download

BS EN 62305-1:2011 pdf download.Protection against lightning Part 1: General principles(IEC 62305-1:2010).
3.13
virtual origin of impulse current
01
point of intersection with time axis at a straight line drawn through the 10 % and the 90 % reference points on the stroke current front (see Figure A.1): It precedes by 0.1 T1 that instant at which the current attains 10 % of its peak value
3.14
time to half value on the tail of impulse current
T2
virtual parameter defined as the time interval between the virtual origin 01 and the instant
at which the current has decreased to half the peak value on the tail (see Figure A.1)
3.15
flash duration
T
time for which Ihe lightning current flows at the point of strike
3.16
duration of long stroke current
TLONG
time duration during which the current in a long stroke is between 10 % of the peak value during the increase of the continuing current and 10 % of the peak value during the decrease of the continuing current (see Figure A.2)
flash charge
0FLASH
value resulting from the time integral of the lightning current for the entire lightning flash duration
3.18
Impulse charge
0SHORT
value resulting from the time integral of the lightning current in an impulse
3.19
long stroke charge
0LONG
value resulting from the time integral of the lightning current in a long stroke
3.20
specific energy
WIR
value resulting from the time integral of the square of the lightning current for the entire flash duration
NOTE It represeslis th, energy dissipated by ttee lightning Current in a unit resistance,
3.21
specific energy of Impulse current
value resulting from the time integral of the square of the lightning current for the duration of the impulse
NOTE The spectec energy en a long troêe current is neghgble
3.22
structure to be protected
structure for which protection is required against the effects of lightning in accordance with this standard
NOTE A structure to be pqotected may be pat of a larger Ctructure,
3.23
line
power line or telecommunication line connected to the structure to be protected
3.24
telecommunication lines
lines intended for communication between equipment that may be located in separate structures, such as a phone line and a data line
3.25
power lines
distribution lines feeding electrical energy into a structure to power electrical and electronic equipment located there, such as low voltage (LV) or high voltage (HV) electric mains
3.26
lightning flash to a structure
lightning flash striking a structure to be protected
3.27
lightning flash near a structure
lightning flash striking close enough to a structure to be protected that it may cause dangerous overvoltages
3.26
electrical system
system incorporating low voltage power supply components
3.29
electronic system
system Incorporating sensitive electronic components such as telecommunication equipment, computer, control and instrumentation systems, radio sy5tems, power electronic installations
3.30
internal systems
electrical and electronic systems within a structure
3.31
physical damage
damage to a structure or to its contents) due to mechanical, thermal, chemical and explosive effects of lightning
3.32
injury of living beings
permanent injuries, including loss of life, to people or to animals by electric shock due to touch and step voltages caused by lightning
NOTE Mhcigh living beings may be nIured in other ways, in the. standard the term injury to liwog beings is limited to he threat du, to .lectricat shock type ol damage Dl).
3.33
failure of electrical and electronic systems
permanent damage of electrical and electronic systems due to LEMP
3.34
lightning electromagnetic impulseLEMP
allelectromagnetic effects of lightning current via resistive，inductive and capacitivecoupling that create surges and radiated electromagnetic fields
3.35
surge
transient created by LEMP that appears as an overvoltage and/or an overcurrent
3.36
lightning protection zoneLPz
zone where the lightning electromagnetic environment is defined
NOTE The zone boundaries of an LPZ are not necessarily physical boundaries (e.g. walls,floor and ceiling).3.37
riskR
value of probable average annual loss (humans or goods) due to lightning, relative to thetotal value (humans or goods) of the structure to be protected
3.38
tolerable riskR
maximum value of the risk which can be tolerated for the structure to be protected
3.39
lightning protection levelLPL
number related to a set of lightning current parameters values relevant to the probabilitythat the associated maximum and minimum design values will not be exceeded in naturallyoccurring lightning.