What is the purpose of the NC contact labeled 'R' in line 1?

• A. To prevent the reverse coil from energizing at the same time as the forward coil
• B. To break the seal-in circuit for the forward coil
• C. Both A & B
• D. None of these

Answer: (A)

In a reversible motor control, you need an interlock so both directions can’t be on at once. The contact labeled R is a normally closed interlock in the line to the reverse coil. When the forward coil is energized, this R contact opens in that circuit, cutting power to the reverse coil. That stops the reverse path from energizing while the forward path is active, preventing a conflict or short between forward and reverse. The function described here is specifically to block the reverse circuit during forward operation, not to break a seal-in in the forward circuit—that would be a different interlock function. So the purpose is to prevent the reverse coil from energizing at the same time as the forward coil.