Sparks Electrical News August 2016

CONTRACTORS’ CORNER

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RELAY TESTING SYSTEM IS QUICK AND EASY TO USE T he FREJA 500-series is the newest mem- ber of Megger's relay testing equipment Megger and the rugged hardware design is

nine current channels are required. The FREJA 549 includes four voltage channels and six cur- rent channels making it possible to test genera- tor protection with differential and undervoltage. The four voltage channels are also needed when testing auto-reclosers with synchro-check. The current capability of these channels must not be skimped – testing a 5 A relay at six times rated current means that a minimum of 30 A is needed, but the capacity to work at even high- er currents is useful in many applications. Old electromechanical protection relays are still in

generators the FREJA 536 provides a complete three-phase test system for commissioning of three-phase protection systems. The FREJA 536 can provide six current generation, and FREJA 549 can provide nine current generation, by converting the voltage channels to currents. The generators also provide high power in both the voltage and current channels to test virtually all types of protection relays. For testing three-phase differential relays, six current channels are needed and, for conveni- ent testing of some special applications, up to

built for field use over a wide temperature range, with the possibility of intelligent software to per- form rapid testing. The instruments have the beneficial combination of high compliance voltage and high current to test all electromechanical, solid-state and numerical- based overcurrent relays, including voltage con- trolled, voltage restraint and directional overcurrent. With three current generators and three voltage

widespread use, and pushing high test currents through these depends on the test set being able to deliver a high output compliance voltage – up to 50 Vrms is highly desirable. Of course, as well as looking to the past with electromechanical relays, it’s also important to look to the future and take into account protection schemes based on the IEC 61850 standard. Most users will not, at present, require facilities for test- ing these schemes, but they will want to know that their test set is future proof and that it will, when the time comes, support IEC 61850 testing. Many test sets are designed to be controlled by a PC and for complex tests this is often the best option. Indeed, Megger offers its widely used FREJA Win software for just this purpose. For simpler tests, however, it is often useful if the test set can be operated as a self-contained unit. The best test sets make autonomous operation very convenient by providing large colour display screens and clear controls. Whether the test set is operated autonomously or with a PC, its software is intuitive in operation, and a recent development of particular value is ‘wizard’-based functionality, as is offered by FREJA Win. This allows the test engineer to set up the instrument for routine tests simply by an- swering a series of straightforward questions. It then provides guidance during the performance of the test, flagging unexpected conditions and results, and providing clear advice on appropriate remedial action. Finally, the FREJA 500-series is capable of generating clear and comprehensive reports in a format that allows the test results to be conveni- ently shared. For more information, contact Megger. WORLD Power Products is a 100% South African- owned manufacturer and a specialist fabricator of high-precision sheet metal products. It boasts extensive design, fabrication and finishing facili- ties at its Johannesburg south headquarters. High- precision, custom-designed sheet metal products account for 70% of production with the balance focused on standard off-the-shelf mild steel and stainless steel cabinets, enclosures, storage sys- tems, locks and hinges as well as perforated sheets. Jan Görtzen, World Power Products’ managing director, says, “All our products are manufactured from original, innovative and unique in-house de- signs which are highly adaptable to offer customers and end users maximum versatility.” The basic cabinet module consists of 2 mmmild steel profiles welded together by means of flanges to form a rigid unit. The PB 3000 fully adjustable robust 19” floor standing mount cabinets, specially designed to house 19” equipment, electronic mod- ules and data modems, are manufactured to indus- try standard heights (12U to 47U) and in accord- ance with DIN 41494. With a standard protection rating of IP40 and manufactured for loads up to 600 kg, this series meets a wide range of require- ments in the IT equipment industry. Enquiries: +27 11 680 5524 Quality products come standard Enquiries: +27 11 391 3832

SPARKS ELECTRICAL NEWS

AUGUST 2016