Soldering

Soldering Points : Soldering, Jointing of bare Copper Conductors, Jointing of Insulated Conductors, Jointing of metal-sheathed cables Joints between conductors are today carried out with the aid of mechanical junctions, and for small cables in particular the system of making twisted, scarf and married joints has been shifted to telegraph wires and temporary wiring. Usually the wires and cables are manufactured in 100 metres lengths. For house wiring, the length may be more or less that 100 meters lengths. For house wiring, the length may be more or less that 100 meters. It is very necessary that the joints should be mechanically and electrically strong. Its importance is realized when damages are caused by bad joints. Hence. it is worthwhile to have good practice for making efficient joints. Jointing of bare Copper Conductors In providing a joints of any kind, contact surfaces must be made such that the resistance of the electrical path does not exceed to that of the unbroken conductor. In this case it can be achieved by thoroughly cleaning and wire brushing, followed by a coating of tinning to prevent oxidation before applying pressure between the surfaces to be joined. Jointing of Insulated Conductors The outer braid should be removed by slicing with a pocket-knife ensuring that the rubber and the conductors are not cut or nicked. The serving tape should be removed and the braiding cut back farther than the rubber and the conductor, thus preventing moisture being carried along the braid to the conductor itself. A good compounded insulating tape should be used to provide a seal for the outer braiding. Jointing of metal-sheathed cables In jointing of metal sheathed cables, the same care must be taken as in jointing the insulated conductors and, in addition and mechanically and electrically continuous joint must be made in the metal sheath. This is normally affected by means of suitably designed metal junction boxes with mechanical gripping devices to provide satisfactory and speedy methods of jointing without the use of solder.