Apart from having different sources for power i.e AC or DC , there are many other differences between AC welding machine and DC welding machine .
| A.C Welding Machine | D.C Welding Machine |
|---|---|
| AC welding machine comprises a step down transformer . | DC welding machine comprises a generator driven by an electric motor or an engine. |
| It is simpler in operation and less costlier . | Complicated operation and cost is two to three times more as compared to that of a transformer. |
| There are no moving parts so no wear and tear .Thus less maintenance. | Due to many moving parts , much wear and tear . Thus , requires more maintenance. |
| High operating efficiency about 85%. | Low efficiency about 30 to 60%. |
| Less electrical energy consumption per kg of metal deposited , about 3-4 kWh. | Higher electrical energy consumption per kg of metal deposited , about 6 to 10 kWh. |
| Power Factor is low , requires capacitors for correction . | Power Factor is comparatively high. |
| Occupies less space | Occupies comparatively less space . |