🔍 Key Concepts

• Heat dissipation in stator windings and how dirt, oil, or moisture on insulation affect it • Relationship between load, ambient temperature, and motor operating temperature • What insulation resistance readings (megger tests) tell you about cleanliness and moisture on windings

💭 Think About

• Ask yourself: If the insulation surface is dirty or contaminated, what change would you most likely see in the motor’s actual running condition for a given load and ambient temperature? • Consider which option describes a symptom that results from poor heat transfer or current leakage in the windings, rather than a mechanical issue. • Think about which condition would directly warn you about insulation problems before an actual breakdown or short occurs.

✅ Before You Answer

• Verify which choice directly reflects thermal stress on the windings rather than mechanical problems like imbalance or misalignment. • Check which option describes a condition that would normally be found by trending temperature versus load and ambient over time. • Eliminate any options that describe conditions that are usually considered good signs (e.g., better than normal readings) rather than warning signs.