by Russell Hattingh, Johnson Controls
Whether to use screw or reciprocating compressors in air conditioning or refrigeration applications is a decades-old question with no simple answer. The fact is, the correct choice depends on a range of factors such as application and operating conditions. Advances in reciprocating (or “recip”) compressors, however, may well add weight to the argument in their […]by Uwe Putlitz, Joint Building Contracts Committee
Subcontractors carry out major and important portions of building and construction work but are far too often last in the queue when it comes to recognition and legitimate treatment. The Joint Building Contracts Committee’s (JBCC’s) Principal Building Agreement (PBA) and the Nominated/Selected Subcontract Agreement (NSSA) are both designed to link the employer with the contractor […]Information from ATI Systems
Eldon is an electrical enclosure range at the right price, quality and service choice. The Eldon sales and service staff at ATI Systems are highly motivated, knowledgeable and attentive. Their level of attention is aimed at long-term partner relationships. Easy engineering and assembly are two of Eldon’s central development drivers. A recent example is the […]Information from DEHN Africa
Notes on providing lightning protection for LED mast lights with double or reinforced insulation; large masts fitted with supply distributors PVC masts and others. LED mast lights for street, walkway and open space lighting are mounted at light point heights of several metres to ensure large fields of illumination. This, however, is only possible if […]Information from Osram
An innovative digital lighting concept brings new splendor to the artistic treasure of the world’s largest basilica. The famous St Peter’s Basilica at the Vatican now shines in brilliant light following nearly 18 months of planning and the installation of a new LED lighting system. The entire lighting concept for the project was tailor-made by […]by Venkat Nandivada Master Bond
Special optical adhesives enable the encapsulation of LEDs, termination of optical fibres and the assembly of complex lens systems. Optical grade epoxies, silicones and UV curable compounds offer engineers great versatility for bonding, sealing, coating and encapsulation applications. These systems adhere well to diverse substrates and offer excellent temperature resistance, stress relief and protection from […]by Hugh Falkner, Fred Nelson, Geoff Parry, Anibal de Almeida and João Fong, Leonardo Energy
This article explores how the cost of condition monitoring for motors can be optimised through examination of the value of each test performed. Part I of this article (see Vector, January 2019, page 24) explores reliability-centered maintenance; the ideal frequency of condition monitoring, the management of spares, assessment of motor efficiency and the risk of […]by Mike Rycroft, EE Publishers
Variable speed drives (VSDs) usually consist of a variable frequency source derived from the main supply by means of a DC converter. Techniques using magnetic coupling allow the motor to be run at its optimum speed while supplying a VSD to the load, as well as providing mechanical separation of motor and load. Magnetic couplings […]Information from ABB
To safeguard their future, mining companies must improve performance, cut production costs, reduce environmental impact, and increase automation. Mining companies face major challenges in terms of sustainable growth. As demand for commodities exceeds supply, mining companies search for new deposits in remote and inhospitable regions where production costs are high. In addition, they seek to […]by Mike Rycroft, EE Publishers
Until recently, the biofuels industry in South Africa was based on maize and jatropha as feedstock. This changed when biofuels were limited to non-food and non-toxic crops. Initial expectations for the biofuels industry in South Africa were based heavily on specific crops as feedstock but the main contenders, maize and jatropha, have been removed from […]by Engineering in Britain Information Services, 1967
From the ICMEESA Archive In food processing applications, pyroclor-filled transformer units save space and curb the costs involved with cable installations. In a modern food factory where electric power may be required for boilers, ovens, dryers, refrigerators and furnaces, as well as for mixing, grinding, sorting and packaging machinery of all kinds, the cost of […]by Dr HA van der Linde and W Leaper, Leaper Innovate Green Energies
Energy storage by compressed air counters the disadvantages of lead-acid batteries while providing a lower energy-to-volume ratio. Lead-acid stationary batteries have been the storage method of choice since 1859 but they have always had the disadvantage of low energy-to-volume ratio. While other, often improved stationary battery technologies have since emerged, they too ultimately face the […]by Russell Hattingh, Johnson Controls
Whether to use screw or reciprocating compressors in air conditioning or refrigeration applications is a decades-old question with no simple answer. The fact is, the correct choice depends on a range of factors such as application and operating conditions. Advances in reciprocating (or “recip”) compressors, however, may well add weight to the argument in their […]Information from Fluke
Failed multimeters are often discovered to have been subjected to higher voltage than the technician thought they were measuring. As distribution systems and loads become more complex, the possibilities of transient overvoltages increase. Motors, capacitors and power conversion equipment such as variable speed drives can be prime generators of spikes. Lightning strikes on outdoor transmission […]Information from Dehn Africa
Not implementing lightning and surge protective measures at PV installations is a recipe for disaster in countries such as South Africa. South Africa is seeing the rise of small-scale embedded generation (SSEG) as end-users and businesses alike work towards reducing their reliance on the national grid. Small-scale embedded generation refers to power generation under 1 MVA, […]