🔍 Key Concepts

• Wye-connected stator windings and how the three phase leads relate to the internal coils • How an ohmmeter reading changes when a coil is open versus intact • The basic purpose and normal use of a growler when testing motor/generator windings

💭 Think About

• Ask yourself: If one stator coil is open, what would you expect to measure between the external motor leads in a wye connection? Would one pair show infinite resistance or just a different value? • Consider what a growler actually detects. Is it usually used to find open circuits, shorted turns, or grounded windings? How does the sound/vibration change? • Think about whether testing between the shaft (rotor) and stator leads can reveal an open in the stator winding or if that mainly checks for grounds/insulation faults.

✅ Before You Answer

• Be clear on the difference between testing between phase leads vs. between shaft and leads and what each test tells you • Verify in your study materials what a growler is primarily designed to detect (open, shorted, or grounded coils) • Confirm how an open coil in a wye-connected three‑phase motor affects the measured resistance across the three external leads