1. GOVERNMENT ENGINEERING COLLEGE DAHOD
TOPIC :- ARC WELDING TRANSFORMER
SUBJECT :- ELEMENTS OF ELECTRICAL DESIGN
PRESENTED BY:-
GUIDED BY :-
PROF :- SHAH PREET

2. .
INTRODUCTION FIGURE

3. WELDING
Welding is a process of joining two or more pieces of the same or
dissimilar materials to achieve complete coalescence.
Welding is accomplished by the use of heat and pressure.
Welding is the only method of developing monolithic structure.

4. ADVANTAGES
A large number of metals/alloys which are similar or dissimilar can be joined by welding.
Welding permits considerable freedom in design.

5. POINTS TO REMEMBER
Electric arc started by striking work with electrode
Heat of arc melts electrode and surface of base metal
Tiny globules of molten metal form on tip of electrode and transferred by arc into molten pool on work surface
After weld started, arc moved along work

6. ELECTRIC ARC WELDING TRANSFORMER

7. A. C. transformers Used to step down a. c. line power voltage to a. c
A.C. transformers Used to step down a.c. line power voltage to a.c. welding voltage
Open circuit voltage runs between volts
Drops to arc voltage when arc struck
Arc voltages
Range: 36 volts (long arc) to 18 volts (short arc)
Determined by arc length held by welder and type of electrode used

8. Voltage generated by welding machine when no welding being done Machine running idle Arc voltage Voltage generated between electrode and work during welding Load voltage Voltage at output terminals of welding machine when arc is going Combination of arc voltage plus voltage drop in welding circuit

9. Device used for holding electrode mechanically Conveys electric current from welding cable to electrode Insulated handle protects hand from heat Jaws of holder grip electrode at any angle Made of metal with high electrical conductivity and ability to withstand high temperatures

10. REQUIREMENTS FOR WELDING ANY METAL

11. Ear Protection Flume Protection
ALSO PROTECT
Ear Protection
Full ear muffs that cover entire ear or ear plugs
Dangers
Noise
Hot weld spatter or slag entering ear canal
Flume Protection
Always use proper ventilation to keep head out of fume plume.