For the overload simulation of metal-oxide varistors, one main parameter is to be considered: W hen testing individual protection measure components, this must be taken into account by choosing appropriate test parameters for each component. As a general rule for protection, the structure to be protected shall be in an LPZ whose electromagnetic characteristics are compatible with the capability of the structure to withstand stress causing the damage to be reduced physical damage, failure of electrical and electronic systems due to ov erv oltages. For more details see IEC Lightning flashes to, or nearby, structures or lines connected to the structures are hazardous to people, to the structures themselves, their contents and installations as well as to lines. All Furse SPDs offer enhanced SPD performance enhanced SPD with industry leading low let-through voltages voltage protection level, Up , as this is the best choice performance with to achieve cost-effective, maintenance-free repeated protection in addition to preventing costly system downtime.
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Expected overcurrents, associated with a specific lightning protection level LPL are given in Tables E. Therefore the efficiency of a protection measure is assumed equal to the probability with which lightning current parameters are inside such range. The ultimate aim of the risk assessment is to quantify and if necessary reduce the relevant primary risks i. The maximum value of the impulse current determines, through the corresponding level of residual voltage, whether the maximum dielectric strength on the resistor collar is exceeded.
This is to ensure that those reinforcing bars likely to carry lightning iec 62305-1 have Figure For parameters exceeding this range, a residual risk iec 62305-1 damage remains. All International European Italian Selector: Lightning is not the only threat… The more stored energy, the larger the resulting transient.
BS EN 62305-1:2011
Also known as IEC In general, the damage due to the acoustic shock iec 62305-1 is insignificant on metal parts of the LPS but can cause damage to surrounding items.
In this case, no laboratory test is necessary 662305-1 check the mechanical behaviour of a conductor bent at a right-angle as long as the cross-sectional areas of the present standard requirements are fulfilled. As a result protection was often fitted after equipment damage was suffered, often through obligation to insurance companies. 62350-1
They are used for positioning of the air-termination system and to define the lightning protection zone LPZ 0 B see 8. Depending on the test item and the iec 62305-1 damage mechanisms, the tests for the first positive impulse or the long stroke can be applied singly or as a combined test, where the long stroke follows the first impulse immediately.
W here an individual evaluation is not possible, the current parameters may be assessed by means of the following procedures. Appropriate SPDs should be fitted wherever common mode and differential mode between live services cross from one LPZ to another. Selection of the most suitable protection measures shall be made by the designer of the protection measures and the owner of the structure to be protected according to the type and the amount of each kind of damage, the technical and economic aspects of the different protection iec 62305-1 and the results of risk assessment.
The time parameters are unchanged. The typical condition encountered in LPS applications consists of natural oscillation periods of the structure much longer than that iec 62305-1 the applied force duration of the lightning current impulse. Numerical values to be considered are those relevant to the lightning flash. When the current is interrupted or switched services connected to the structure, e.
Therefore it is vitally important to use a I I correctly designed air termination system. NOTE 2 These systems usually fall under special regulations produced by various specialized authorities.
Enhanced SPDs Whilst outright damage to equipment is not desirable, the need to minimize downtime as a result of iec 62305-1 of operation or malfunction of equipment can also be critical.
The lower the earth electrode resistance the more likely the lightning current will choose to flow down that path in preference iev any iec 62305-1, allowing the current to be conducted safely to and dissipated in the earth l Good corrosion resistance. Risk management IEC All measures iec 62305-1 protection against lightning form the overall lightning protection. Information on surges due to lightning at different installation points is given in Annex E.
Structural lightning protection can no longer be in isolation from transient overvoltage or surge protection of equipment.
BS EN IEC standard series | Konika Hossain –
Effects of lightning current causing possible damage Uec effects Thermal effects linked with lightning current are relevant to the resistive heating caused by iec 62305-1 circulation of an electric current flowing through the resistance of a conductor or into an LPS. In this case, the peak value of the current impulse and its specific energy needs to be reproduced during the test.
The system to be protected shall be located inside an LPZ 1 or higher. The value of the probability of occurrence of lightning current peak v alues exceeding the prev iously considered is reported in Table A. For an unshielded drop wire, values could be 5 times higher.
NOTE It is assumed that the resistance of the idc is approximately equal to the resistance of all line conductors in parallel. Lightning protection is cost effective if the sum of the cost C RL of residual loss in the presence of protection measures and the cost C Iec 62305-1 of protection measures ied lower than the cost C L of total loss iec 62305-1 protection measures: Help Center Find new research papers in: