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