Electricity + Control October 2015

EARTHING + LIGHTNING PROTECTION

Testing of LPS components.

In many cases, we have found that substandard (Grade ‘B’) earth elec- trodes with a copper cladding of 40 microns are being used by many installers of earthing and lightning protection systems. This practice is non-compliant and should be avoided at all costs. A specimen of two coupled rods undergo an ‘Impact Test’ by means of a vibration hammer with a blow rate of 2 000 ± 1 000 min with a kinetic energy of impact 50 ± 10 (Nm) is applied to the top of the rod. If the rods or the couplings pass the above test without visible defects, they are sub- jected to artificial ageing and are loaded with three lightning current impulses of wave shape 10/350 μs of 50 kA and 100 kA each. In order to pass the test the transition resistance (via the coupling) must not exceed 2,5 m Ω . After the lightning impulse test the coupling is then subjected to a tensile strength test to determine whether or not the connection is sufficiently strong after the induced lightning currents. Conclusion The installation of a functional lightning protection system requires that the components and devices are tested in accordance with the latest standards. Only lightning protection systems that comprise components that are manufactured and tested in accordance with the SANS / IEC 62561 [2] series of standards can be considered to be compliant. Manufacturers` test reports must accompany all lightning protection system certification. References [1] SANS/IEC 62305. Lightning Protection Standard (LPS) series. [2] SANS/ IEC 62561: Lightning Protection SystemComponent (LPSC) series. Bibliography DEHN Lightning Protection Guide 3 rd Edition. DEHN Lightning Protection / Earthing Catalogue - January 2015 edition.

MV clamp for a test in the impulse current laboratory.

• Components and devices in functional lightning protection systems must be tested according to the latest standards before installation. • Only components and devices tested in accordance with SANS/IEC 62561 are considered to be compli- ant. • Manufacturers’ test reports must accompany all lightning protection system certification.

take note

Trevor Manas started his lightning protection career at Pontins in 1991 as an installation technician. Within two years, he was promoted to a sales engineer position. In 1996, he was promoted to the position of director and was in charge of ensuring the company`s compliance with the earthing and lightning protection codes of practice. In 1999, Trevor became the managing director of Pontins. Enquiries: Email trevor@pontins.co.za

Electricity+Control October ‘15

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