🔍 Key Concepts

• SCR (Silicon Controlled Rectifier) / AC-DC drive systems versus straight DC systems on drilling rigs • The role of an AC bus and a DC bus in distributing power to multiple motors • Mechanical components in DC machines, especially commutators and brushes

💭 Think About

• Think about what changes when you first generate AC power, distribute it, and then convert it to DC near the machinery, instead of generating and distributing DC directly. • Which option describes a benefit that affects the entire rig power distribution system, not just one motor? • Consider which features would reduce heavy mechanical maintenance and which would improve flexibility in how power is shared among many loads.

✅ Before You Answer

• Identify which choice deals with system‑level power distribution rather than a single piece of equipment. • Ask: does this option clearly involve using a common AC power source that can serve many converters/drives? • Verify which statement describes a true engineering advantage commonly cited for SCR/AC‑DC systems on drilling rigs and not something that is actually untrue or oversimplified (like calling them "simpler").