Electricity + Control January 2017

ROUND UP

EARTHING + LIGHTNING PROTECTION

Optimal surge protection for wind turbines with DFIG systems

2015 saw a huge boost for the wind industry, with annual installa- tions surpassing 60 GW for the first time in history. At the end of last year, the new global total amounted to 432,9 GW, denoting a cumulative market growth of more than 17%.

This unprecedented growth has led to an increased concern around the lighting and surge protection of wind turbines, a concern that is addressed by the introduction of DEHNguard DG SE H 1000 VA FM surge protector, specifically designed to minimise the risk of failure resulting from surges when it comes to wind turbines with doubly-fed induction generator (DFIG) systems. This powerful new arrester is rated for voltages up to 1 000V and discharges currents up to 40 kA (8/20 µs). Its module locking system ensures that neither shock nor vibration during transportation and use, or even an enormous force of discharge, can loosen the protec- tion modules.The protection modules can also easily be replaced - without tools - by simply pressing the module release button. DEHN guard SE H 1000 VA FM is ideally suited for wind turbines (with DFIG-Double Fed Induction Generator), however it can also be used for other applications with up to 100 V, such as, photovoltaic (PV) systems, railways systems, industrial plants and cable cars. Enquiries: Kirk Risch.Tel. +27 11 704 1487 or email kirk.risch@dehn-africa.com * Automatic disconnection of supply * Polarity * Functional performance In addition to this the following tests are under consideration: • Electric strength test; • Voltage drop. The basic requirements for test equipment used in installation test- ing consists of general requirements for test equipment, specific requirements for combined measuring equipment and the specific requirements for measuring/testing: • Insulation resistance • Loop impedance • Resistance of the earth connection • Resistance to earth • RCD performance in TT and TN systems • Phase sequence • Insulation monitoring devices for IT systems Available from Comtest , the Fluke 1660 Series Multifunction Instal- lationTesters are measuring equipment which fully fulfil the require- ments as described above, and the three different models in the series comply with specific parts of this norm.They are specifically designed to carry out the tests specified, and all local standards and regulations in the safest and most efficient way. Enquiries: Comtest.Tel. +27 (0) 10 595 1821 or email sales@comtest.co.za

Installation testing protects appliances, wirelessly shares data

Growing concern for public safety and the increasing complexity of today’s fixed electrical installations in domestic, commercial and industrial premises places extra responsibility on electrical test engineers who are charged with verifying conformity to South Africa’s Certificate of Compliance (COC) safety standards. SouthAfrica’s electrical contractors are well versed in the verifica- tion requirements of the COC, and that the audit should be carried out in the following sequence: • Visual inspection • Testing of the following: * Continuity of protective conductors * Insulation resistance * Protection by separation of circuits * Floor and wall resistance

Introducing arc protection system to local market

DEHN Africa recently launched its DEHN- short arc fault protection system to the local market, with an intensive training session held at its Johannesburg office. Overseen byAndreas Schumacher, Prod- uct Manager: Safety Equipment/ Arc Fault Protection from DEHN + SÖHNE, DEHN Africa sales engineer, Tatenda Gora, con-

ducted the training which was entitled:The Introduction of DEHNshort to South Africa - protection through detection for arc faults in low voltage switchgear assemblies. The training session covered topics including a description of arc faults; the standards and norms of arc fault protec- tion; an introduction to the DEHNshort

product and its application; as well as a demonstration of the new product offering. The comprehensive training was aimed both at DEHN Africa staff and partners as well as local clients. Enquiries: Kirk Risch.Tel. +27 (0) 11 704 1487 or email kirk.risch@dehn-africa.com

Electricity+Control January ‘17

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