Question 3277 Deck General

The correct answer is C) Required power can be drawn from a common AC bus. The chief advantage of an SCR or AC-DC system over a straight DC system for powering drilling rig machinery is that the required power can be drawn from a common AC bus. This allows for more efficient power distribution and easier integration with the rig's overall electrical system, as AC power can be more easily transmitted over longer distances compared to DC power. The other options are not as relevant - commutators are not a significant factor, SCR systems are not necessarily simpler, and multiple DC-powered machines can be operated from a DC bus, but the ability to tap into a common AC power source is the key benefit.