🔍 Key Concepts

• Identify which devices are normally open (NO) and which are normally closed (NC) in a standard motor starter circuit • Think about what changes state when the motor is running normally versus when it is starting or in an overload (OL) condition • Understand how the holding (seal‑in) circuit using auxiliary contact M keeps the motor energized after the start button is released

💭 Think About

• When the motor is running normally, which component actually keeps the control circuit energized: the start push-button or auxiliary contact M? • In a normal (non‑trip) condition, would the overload contact OL be carrying current (closed) or interrupting current (open)? • After you release the start push-button, what position do its contacts return to, and how does that compare to the stop push-button’s normal position?

✅ Before You Answer

• Verify which devices in the diagram are labeled as NO and which as NC at rest • Confirm that in normal operation with the motor running, the overload has not tripped, so its contact state reflects that condition • Trace the control circuit path from L1 through the stop, start, M contact, and OL to the coil, and note which single device must be open while everything is operating properly