Which device is used to cool larger AC welding machines?

• A. Electric-motor-driven fan
• B. Water-cooled radiator
• C. Air-cooled cabinet
• D. Manual blower

Answer: (A)

Cooling a welding machine hinges on getting heat away from the power components. An electric-motor-driven fan provides active, forced air cooling, pushing air through the machine's internal passages to carry heat away from transformers, rectifiers, and other hot parts. This setup is reliable and simpler than adding a water-cooling loop, making it well-suited for larger AC machines that still need portability.

Water-cooled radiators are more efficient but add plumbing, pump, radiator, and coolant maintenance, which is why they’re typically reserved for the very largest or most duty-heavy units. An air-cooled cabinet doesn’t actively remove heat beyond the built-in cooling airflow, and a manual blower isn’t practical for sustained cooling. So the device used to cool larger AC welding machines is the electric-motor-driven fan.