How to size a generator set

  Many factors influence generator set sizing, making it time consuming to manually calculate required generator capacity. Parameters that determine the required generator set size include minimum generator set load; maximum allowable step voltage dip and step frequency dip; altitude and temperature; duty cycle, fuel, phase, frequency and voltage. Sizing software, such as Cummins Power […]

The causes and effects of inter-system ground noise

  Non-isolated computer equipment connections such as RS-232, parallel and USB can cause inter-system ground noise which AC power protection equipment cannot correct. The uninterruptible power supply (UPS) system is essential to any business computer system but it cannot protect the computer completely from all power related problems. Energy management company Schneider Electric has identified […]

Not-so-smart metering: an end-user’s point of view

  Smart metering, we have been told, allows the utility to read the meter remotely and the end-user to monitor and control energy consumption. The reality, however, is somewhat less appealing. Never having had such a facility available before makes one fairly ignorant of what can be expected and, as is usual in these cases, […]

Lightning protection: leave it to the experts

  by Hans van de Groenendaal, EE Publishers Lightning protection is a serious, yet often underestimated issue, which requires professional equipment, installed professionally. Dehn Protection South Africa MD Alexis Barwise shares some strong views on the subject. Barwise says it is inadvisable to apply a rule of thumb and to think you and your property […]

Benefits of simulation models for assessing energy savings on mine cooling systems

by Alistair Holman, Dr. Johann van Rensburg and Dr. Deon Arndt, CRCED Pretoria, North West University At a time of immense economic pressure and fragile labour relations in South Africa, it is important for mines to be energy efficient, reduce energy costs, ensure safe working conditions and to minimise unwanted downsizing. Download PDF

Characteristics and performance of a carbon dioxide trans-critical water to water heat pump

by Paul Maina and Zhongjie Huan, Tshwane University of Technology A study and findings on improvements in the efficiency of high-pressure CO2 heat pumps by varying their various operational parameters. Download PDF

Commercial heat pumps: a retrospective M&V case study

  by R Larmour, University of Cape Town Aspects of the measurement and verification (M&V) of a commercial energy efficiency project including optimal data usage; target specification and the possible effects of the subsidy structure on M&V credibility. Download the Pdf

Truths about UPS safety

  by Bob Lauricella and Zach Greenhaw, Eaton This article answers some common questions about UPS maintenance and how to reduce the risks associated with servicing UPSs and their batteries. When working with data center and commercial facility power systems, shocks of 100 to more than 2000 mA are possible. Energised electrical equipment also presents […]