China
Africa
Explore chapters and articles related to this topic
Introduction to Composite Materials
Published in Robert M. Jones, Mechanics of Composite Materials, 2018
In the 1960s, aluminum wire clad with about 10% copper was introduced as a replacement for copper wire in the electrical wiring market. Aluminum wire by itself is economical and lightweight, but overheats and is difficult to connect to terminals at wall switches and outlets. Aluminum wire connections expand and contract when the current is turned on or off so that fatigue breaks the wire causing shorts and, consequently, potential fires. On the other hand, copper wire is expensive and relatively heavy, but stays cool and can be connected easily to wall switches and outlets. The copper-clad aluminum wire is lightweight and connectable, stays cool, and is less expensive than copper wire. Moreover, copper-clad aluminum wire is nearly insusceptible to the usual construction-site problem of theft because of far lower salvage value than copper wire.
Power Delivery Systems: Transmission and Distribution
Published in J. Lawrence, P.E. Vogt, Electricity Pricing, 2017
A number of aerial conductors are used in overhead primary distribution lines. While copper wire has less resistance than aluminum wire of the same cross-sectional area, it is also heavier and more costly. Therefore, aluminum conductors are used more often now for new primary line construction. However, a considerable number of copper conductors currently exists in older portions of distribution systems. Copper conductors do have an application in modern distribution construction, such as for jumper wires for connecting transformers and other line equipment to the primary lines. Copper wires are also used to ground electrical equipment and the neutral conductor by means of copper ground rods driven into the earth at the base of poles where prescribed by construction standards. A list of many of the sizes and types of aerial conductors that are manufactured for distribution applications is provided in Table 5.4.
Fixed Electrical Contacts and Joints
Published in Frank W. Kussy, Jack L. Warren, Design Fundamentals for Low-Voltage Distribution and Control, 2017
Frank W. Kussy, Jack L. Warren
There are several acceptable ways to connect cables. These include wire-bending screws, crimp-on wire-grip connectors, screw-type connectors, and spring-type connectors. For any of these connectors, care must be taken to use the proper connector material, particularly with aluminum wire. Before 1972, there were no special UL endurance test requirements for aluminum wire connections. Steel or copper wire-bending screws and wire grips were often used to fasten aluminum wires in residential housing. Aluminum wire has a higher coefficient of thermal expansion than that of a steel or copper screw lug. After repeated heating and cooling, the wire extrudes and the connections become loose. After a period of years, overheating can occur and a serious fire hazard can result. All such installations should be rewired to eliminate this hazard. Connections of aluminum wire with a wire-bending screw to copper should be made with a wire nut. The copper wire should be connected to the terminal.
Numerical model of natural convective heat transfer within a solar dryer using an indirect double pass collector
Published in International Journal of Ambient Energy, 2018
R. Srinivasan, T. Balusamy, M. Sakthivel
The drying chamber was designed based on many factors, such as the quantity of product to be dried, the required velocity of air and the relative humidity of air passing through the food material. The drying chamber has dimensions of 500 mm×500 mm×750 mm and it was made by wood of 5 mm thickness. The drying chamber houses three trays with dimensions of 500 mm×500 mm and made of aluminium wire mesh. The gap of 100 mm is provided between trays. This dryer has the capacity of drying 1 kg of any product. A conical-shaped chimney provided at the top of the drying chamber has dimensions of 200 mm diameter at base, 65 mm diameter at exit and 1000 mm height. The chimney was made of 0.7 mm-thick aluminium sheet and it is painted black at the outer surface to enhance the chimney effect. The chimney effects the air flow rate by the principle of buoyancy (Koua and Fassinou 2009).
High-performance programmable grounded resistor and its applications
Published in Automatika, 2018
Charu Rana, Dinesh Prasad, Neelofar Afzal
The interconnect resistance of MOSFET also gets affected by temperature variations and is expressed as below: where Ri is a resistance at temperature Ti and the value of α is an empirical temperature coefficient of resistance with value 0.004 for copper wire and 0.0043 for aluminium wire. R0 and T0 are reference resistance and temperature, respectively. Suppose R0 is 30 kΩ at 20°C, the value of Ri at 30°C is 30.12 kΩ for copper and 30.129 kΩ for aluminium after using Equation (12) and results in an increase of 4% and 4.3%, respectively. It can be seen that the variations in interconnect resistance and mobility due to temperature will almost nullify each other. Thus, proposed circuits are less prone to error due to temperature variations.
Design improvement of flexible textile aluminium-air battery
Published in The Journal of The Textile Institute, 2020
Aleksandrs Vališevskis, Uģis Briedis, Žaneta Juchnevičienė, Milda Jucienė, Miguel Carvalho
Rigid aluminium wire mesh (0.28 mm diameter wire) is compared to Mtex® aluminium-textile composite material. Mtex® fabric has textile base and textile-like tactile feel, but is not permeable, thus it is used only in the underlaying layer. Please note that for this experiment batch 20x20 mm size cells were prepared with 6.25 times smaller surface area than for other experiment batches. Cells of this size are intended for use in multicell batteries, which are currently in the development phase. The results are presented in Table 2. Voltage-current characteristic is shown in Figure 2.