🔍 Key Concepts

• Trace the control circuit from the GP supply, through the overload relay and control relay (CR), to the two indicator lamps labeled Run and Overload. • Understand how an overload relay works: on overload it changes the state of its auxiliary contacts, which both drops out the motor contactor and sends a signal to an alarm/indicator. • Note the dashed lines between the relay coils and contacts (P1–P6). These show which contacts change state when the coil is energized or de‑energized.

💭 Think About

• In a motor overload condition, will the line contactor (LC) and control relay (CR) be energized or de‑energized? How does that affect the Run lamp circuit path from the GP supply to P5? • Look at contacts P3 and P4 associated with the overload relay. In an overload trip, do these contacts close or open, and what does that do to the Overload lamp circuit to P6? • Compare the current path to each lamp for two situations: (1) motor running normally and (2) overload relay tripped. Which lamp(s) can still get power when the overload relay has opened the circuit to the line contactor coil?

✅ Before You Answer

• Verify which contacts in series with the Run lamp (contact CR) are normally open and only closed when the motor is commanded to run. • Verify which contacts in series with the Overload lamp (P3–P4) are arranged to change state only when the overload relay trips, not during normal running. • Be sure that in an overload condition, the motor is no longer energized (LC drops out), so any statement that implies the motor is still running should be viewed critically.