Electricity + Control April 2019

round up ELECTRICAL PROTECTION + SAFETY

Smart power solutions

inverter/charger will automatically switch over to the grid and recharge the batter- ies. When the preselected state of charge is reached, the load is switched automat- ically and seamlessly back to the inverter. The generator-assisted mode is used in an off-grid situation. The batteries are charged from an installation of solar panels and/or wind generators and the load re- quirements are permanently serviced from the inverter. In the event that the renewa- ble energy supply and/or the battery power is insufficient to service the required load, a suitably sized back-up generator is used. While the generator is running it charges the batteries and once the required charge has been met, the system automatically switches back to the inverter – thus opti- mising the run-time of the generator. Netshield’s smart power solutions of- fer customers a range of power supply and storage options to ensure reliable power feeds to critical business services. Enquiries: Marien Dreckmeyr at Netshield SA.Tel. +27 (0)12 841 0320, or email: sales@netshieldsa.com

With the national power system in its present state, load shedding has become a daily disruption as it reduces the risk of a national blackout. But that doesn’t reduce the impact on business. It has become critical for businesses to make alternative power arrangements. One such alterna- tive is the Netshield Inverter and Battery Charger range. Inus Dreckmeyr, CEO at Netshield South Africa, says running a generator is still a costly power supply option and put- ting all business equipment and devices onto an alternative power system is not generally financially viable or practical. In- stead, Dreckmeyr suggests that business- es need to decide what their ‘core’ energy requirements are, calculate the power re- quirement for the exact use case, and then build a solution to fit these requirements. The Netshield Inverter/Battery Charg- er range, a true sine wave inverter and high-power battery combination provides a flexible power sourcing solution. The inverter/battery charger unit can be used in three use cases, defined as: high-

power deep cycle line interactive UPS mode, grid-assisted mode, or as a genera- tor- and grid-assisted energy source. The high-power deep cycle line interac- tive UPS mode is used when the power utility implements load shedding, or when there is an unstable grid connection. The inverter/charger is used as a backup pow- er source. When the grid is available, the charger keeps the batteries (not included) fully charged and the load runs from the grid. When the grid power feed fails, the inverter automatically switches into online mode, within 12 milliseconds, to supply the load. Backup time is scaled in line with the actual load requirements and the siz- ing of the connected battery bank. The grid-assisted inverter mode is used when there is a grid connection as well as additional renewable energy supply, from photovoltaic solar panels, for exam- ple. In this case, the inverter, which runs from the battery and renewable resource, provides the primary energy feed. In the event that the alternative sources and bat- teries cannot supply sufficient power, the

Electricity + Control

APRIL 2019

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