🔍 Key Concepts

• Forward/reverse motor starter control circuits and how the F (forward) and R (reverse) contactor coils work • The difference between normally open (NO) and normally closed (NC) auxiliary contacts when a coil is energized vs de‑energized • Mechanical/electrical interlocking in Figure B that prevents both forward and reverse contactors from being energized at the same time

💭 Think About

• When the motor is running forward, which contactor coil must be energized, and which one must be de‑energized? Trace that in Figure B. • For an energized coil, what happens to its own NO and NC auxiliary contacts throughout the circuit? Now, what about the contacts belonging to the de‑energized coil? • Look at the interlock contacts labeled F and R in series with each coil. In forward operation, which of those must be open or closed to prevent the opposite direction from starting?

✅ Before You Answer

• Identify which coil (F or R) is actually powered when the circuit is in forward run and confirm the current path from L1 to L2. • For each statement, verify whether it matches the real state of that device’s NO/NC contacts under coil energization (not their resting state). • Confirm that any contact belonging to the non‑energized coil is still in its normal (rest) position, since that coil is not picked up.