The ZANDZ project continues the cycle of training activities.
On 3 April at 11:00 (Moscow time) we will hold the webinar «Creeping discharges in lightning protection».
It is known since the beginning of the previous century, that having achieved a lightning rod or some other on-ground structure, the development of lightning may continue at the expense of forming the spark channel along the ground surface. Such creeping charges may be distributed to dozens of meters leaving specific traces on the ground surface, looking like rigs at the tillage. Therefore, lightning current can enter the protected territory, not from above, but from the bottom, by-passing the installed lightning rods.
Several years ago it was considered that extended creeping discharges are characteristic only of high-resistance soils, in which their length can be about a hundred of meters. Recently our native specialists created a mobile source of a pulse current with record parameters, which is capable of imitating lightning current with an amplitude of 100 kA. The tests carried out with its help proved the possibility of forming creeping spark discharged dozens of meters long in high-resistance soils, for example in black soil or in moist clay. They can present serious danger for underground cable cicruits of control and automation, can burn up hydrocarbon fuel leakage or heavy gas mixtures becoming the source of fires.
Unfortunately, there is no word about creeping discharges and discharge fighting methods in the native regulatory documents AD 34.21.122-87 and IS-153-34.21.122-2003. Due to this reason, the planned webinar will concentrate on the calculation method of estimation of the ultimate length of spark channels, means of their reduction and protection means against their penetration to the protected territory.
You can learn more about creeping discharges and discharge-fightning methods during our webinar.
Cost: free, registration required.
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