CHAPTER ONE
HISTORY/INTRODUCTION
1.0            The machine is specially designed for industrial and agricultural welding. It is only powered from A.C power source for all welding.
The unit is designed to operate on single phase 240v A.C. supply and it is mainly a transformer unit. It is capable of operating from 25 Amps socket for most of its output range. The current drawn form the mains supply may exceed the 25 Amps, hence the unit must be provided with 30A switch fuse input as those provided for electric cookers, heaters etc. this connection must be made to the dead side of a 30A circuit. The circuit should not be shared by any other appliance.
          The unit consists of the following main components single phase transformer (with tap changing secondary). The transformer is a step-down transformer with different tapping at H, M and L; welding tung cables.
          The transformer is a conventional-cooled, single phase transformer which has shell type of lamination core and insulated windings of copper cols. In addition, the windings are given double insulation with the use of varnish solution which helps to prevent short-circuiting in the windings.
With the help of Angle iron and lamination core, the core loss, iron loss in the machine is reduced to minimum. They also help to reduce humming in the machine. Hence, efficiency of the machine is greatly improved.
1.1            AIMS AND OBJECTIVES
Sequel to the vast need and use of iron rods, metal bars and pipes, right from the domestic level up to industrial extent, the arc welding machine was built in order to ensure that the ulterior motive of the manufacturers of these products (iron rods, metal bars and pipes) by their manufacturers is being achieved as part f technological advancement. With the electric Arc welding machine, the difficulty of using iron rods, bars and pipes in construction works has been removed.