Electricity + Control June 2015

ELECTRICAL PROTECTION + SAFETY

Figure 7: Test set-up for a complete LED street lighting system in the laboratory.

Conclusion The laboratory tests in cooperation with LED light manufacturers and the practice-oriented system test of a complete LED system, consisting of a cable distribution cabinet, metal mast, cable junc- tion box and LED light – in conjunction with practical experiences are important elements of an efficient protection concept for LED street lighting systems. A well-founded protection concept can only be implemented by means of a complete system consisting of cascaded SPDs (see Figure 5 ) which is specifically developed for this application, in the cable junction box or in the LED light and a coherent earthing concept where all metal masts must be con- nected to the protective conductor of the SPDs used. This allows safety control potential differences and ensures the availability of the LED street lighting system – also in the case of surges. This is the only way to ensure that an investment for retrofitting street lighting systems with the new LED technology achieves the predicted lifetime and uncalculated follow-up costs are prevented.

References [1] IEC 61000-4-5. 2014. Surge immunity.

[2] EN 61643-11. 2011. Low voltage surge protective devices. Part 11: Surge Protective Devices connected to low voltage power systems – requirements and test methods. [3] IEC 60364-4-41:2005. Low-voltage electrical installations - Part 4-41: Protection for safety - Protection against electric shock. [4] IEC EN 60598-1. 2008. Practical guide to testing and certifica- tion requirements for luminaires.

Bernd Leibig studied Electrical Engineering at the University of applied Science Georg-Simon-Ohm Nuremberg. Between 1993 and 2008 he held various positions in R&D, sales and project management at DIEHL Stiftung Nuremberg / Germany. Since 2008 he has been product manager, surge protection red / line Dietmar Dürr studied Electrical Engineering at Grundig Academy in Nuernberg. In1998 he joined Dornier Medical Systems as a field Service Engineer. From 2000 to 2009 he was employed by DEHN + SÖHNE, in various positions. He worked as key account manager for SMA from 2009 to 2014. He is currently area sales

at DEHN + SÖHNE GmbH + Co. Kg. in Neumarkt / Germany.

manager with DEHN + SÖHNE. Enquiries: Alexis Barwise. Email alexis.barwise@dehn-africa.com