The average no-load voltage in a DC arc welding circuit is _____ volts.

The average no-load voltage in a DC arc welding circuit is _____ volts.

• A. 10-20
• B. 15-30
• C. 60-80
• D. 15-40

Answer: (C)

The key point is the open-circuit (no-load) voltage of the welding power source. In DC arc welding, this no-load voltage is kept around 60 to 80 volts. It has to be high enough to reliably strike the arc when the electrode is brought to the work, but not so high that it creates excessive hazards when the circuit is open. Once the arc starts, the voltage drops to the arc voltage (usually around 20–40 V) while the current is controlled by the welding setting. The lower ranges in the other options wouldn’t reliably initiate the arc, which is why the 60–80 volt range is the proper choice.

The key point is the open-circuit (no-load) voltage of the welding power source. In DC arc welding, this no-load voltage is kept around 60 to 80 volts. It has to be high enough to reliably strike the arc when the electrode is brought to the work, but not so high that it creates excessive hazards when the circuit is open. Once the arc starts, the voltage drops to the arc voltage (usually around 20–40 V) while the current is controlled by the welding setting. The lower ranges in the other options wouldn’t reliably initiate the arc, which is why the 60–80 volt range is the proper choice.