CWS Welding Equipment & Maintenance

Question 1

Which power source output characteristic is normally used for SMAW?

Accepted Answer

Constant current (drooping)

Answer

SMAW uses constant current so amperage stays fairly stable as the welder's arc length changes.

Question 2

A power source is rated at 300 A at a 60% duty cycle. What does this mean?

Accepted Answer

It can weld at 300 A for 6 minutes out of every 10 minutes

Answer

Duty cycle is the percentage of a 10-minute period a machine can run at rated output without overheating.

Question 3

A machine is rated 200 A at 60% duty cycle. About what duty cycle is allowed at 150 A?

Accepted Answer

About 100%

Answer

Allowable duty cycle = (rated A / actual A)² × rated duty cycle = (200/150)² × 60 ≈ 107%, capped at 100%.

Question 4

On a constant-voltage GMAW power source, what mainly controls welding current?

Accepted Answer

Wire feed speed

Answer

With CV output, raising wire feed speed raises the current the machine supplies to melt the wire.

Question 5

In short-circuit GMAW, raising the inductance setting usually does what?

Accepted Answer

Slows the rate of current rise, giving a softer arc with less spatter

Answer

Inductance limits how fast current rises during each short circuit, which cuts spatter and makes the puddle more fluid.

CWS - Certified Welding Supervisor Practice Test