Page 38 - CITS - Welder - Trade Theory
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WELDER - CITS



           Principle of Arc welding
           When high current passes through an air gap from one  conductor to another,  It  produce very intense and
           concentrated heat in the from spark.

           The temperature of this spark /arc is approx 3400° C to 4000°.Which can melt and fuse the metal very quickly to
           produce a homogeneous weld.






























           Characteristics of Arc
           Welding power source construct and design deferent shape and size. Supply the current AC and DC both .and its
           voltage and amperage output are controlled.





























           Constant current characteristics

           Constant Current power  source  is used with a coated electrode.  This type power  sources less variation  in
           amperage and greater variation in arc voltage. Slightly increasing the arc length increase  the arc voltage and
           decreases arc amperes.
           Constants voltage  characteristics:  The voltage is always constant, the voltage is set  while  the amperage
           depend on the speed of wire feed in the welding gun.
           Increasing the speed of the wire feed increases the amperage. And decreasing with decreasing.



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                                          CITS : C G & M - Welder - Lesson 6&7
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