Electricity + Control August 2017

ELECTRICAL PROTECTION + SAFETY

abbreviations

MCR – Measurement, Control and Regulation EMC – ElectroMagnetic Compatibility IT – Information Technology PLC – Programmable Logic Controller SMS – Short Message Service SPD – Surge Protective Device

Conclusion In water and wastewater treatment, there is an in- creased failure risk in large systems due to surge voltages, often with far-reaching consequences for persons and the environment. A comprehensive and well-planned lightning and surge protection concept is therefore crucial. Using surge protec- tion with telecommunicating status indication en- sures quick detection in the control room. Due to the compact design − with only 3,5 mm width for the narrowest components − the space needed for MCR surge protection can be reduced signifi- cantly. Used in explosion-protected areas it is trou- ble-free with the available approvals. Thanks to the comprehensive product range, there is a suitable solution for every application in water and waste- water technology. References [1] DIN EN 62305-2. 2013. Protection against lightning − Part 2: Risk management. [2] DIN EN 60079-0. 2013. Explosive atmospheres − Part 0: Equipment − General Requirements. [3] DIN EN 60079-11. 2012. Explosive atmos- pheres − Part 11: Equipment protection by in- trinsic safety ‘I’. [4] DIN EN 61643-21. 2013. Surge protective de- vices for low voltage − Part 21: Surge protec- tive devices connected to telecommunications and signaling networks − Performance require- ments and testing method.

Use also in explosion-protected areas A lightning and surge protection concept is es- sential because of the higher risk in potentially ex- plosive structural systems, often with far-reaching consequences for persons and the environment. In general, observation of lightning protection standard DIN EN 62305 [1], applicable for nearly all structural systems, is sufficient. Part 2 of the standard describes risk management for structural systems, which takes into account the effects of lightning strikes. The standard relates to all struc- tural systems − even systems with explosion risk in accordance with DIN EN 60079-0 [2]. The ‘in- trinsic safety Ex-I’ type of protection is useful as a secondary protection measure in this environ- ment. This type of protection limits voltages and currents so that a potentially explosive mixture of ignition energy and temperature is not reached. DIN EN 60079-11 [3] is the specific standard for these intrinsically safe circuits − here too, refer- ence is made to the necessity of lightning and surge protection. For all systems that require high availability, a failure lasting for even a short time is unaccept- able. That is why the requirements for surge pro- tection are also more stringent for such systems. The surge protection of the Termitrab complete TTC-Ex product range was designed for such systems. The Ex-i certification of the TTC-Ex com- ponents permits the use in field distributors for Ex-zones 1 or 2. Additional approvals attest to the suitability in accordance with Fisco (fieldbus intrin- sically safe concept).

Take Note!

Lightning and surge protection is essen- tial in large water and wastewater treatment systems. Many manufacturers offer MCR surge protec- tive devices. This company has launched the world’s narrowest (3,5 mm wide) surge protection for MCR.

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Dipl.-Ing. Ralf Hausmann is in Product Marketing, Surge Protection Trabtech at Phoenix Contact.

tonyr@phoenixcontact.co.za www.phoenixcontact.com/webcode/0144

16 Electricity + Control

AUGUST 2017