🔍 Key Concepts

• Open motor enclosure versus totally enclosed or drip-proof types • How much of the internal windings/rotor are directly exposed to the surrounding air • Presence and size of ventilation openings or slots in the housing

💭 Think About

• Compare how much of the inside of each motor you can actually see—on which one are the internal parts least protected by a full outer shell? • Which motor would allow dust or fingers to reach the rotor or windings most easily because there is no substantial outer casing in the way? • Look for the motor whose cooling relies on being almost completely exposed to ambient air rather than air moving through small vents or over fins.

✅ Before You Answer

• Identify which illustration shows large, unobstructed openings or nearly no enclosure around the rotor and windings • Eliminate any motor that clearly has a continuous outer shell with only small vents or fins for cooling • Before choosing, ask: "On this motor, could I almost touch the rotor/windings from the outside?" — if not, it is probably not the open enclosure type.