🔍 Key Concepts
• Wye-delta starting sequence: which contactors are closed during START, TRANSITION, and RUN
• How the motor leads T1–T6 are connected to form wye versus delta in this diagram
• Role of the R contactor and resistors in changing from reduced-voltage to full-voltage operation
💭 Think About
• Identify which contacts (M, S1, S2, R) are energized immediately after you press START, and how that connects the motor windings
• During the transition period (when the timer CR(TC) operates), which contactors must change state so the motor moves from wye to delta without being disconnected from the line?
• When the motor is in its final RUN condition, trace whether current still passes through any resistors or only through solid contactor paths
✅ Before You Answer
• On the power diagram, carefully trace the path from L1, L2, L3 to T1–T6 with R open and then with R closed
• Confirm in which periods (START, TRANSITION, RUN) the R coil is energized by reading the control diagram at the bottom
• Be sure whether R is associated with the delta connection, the wye connection, or only with inserting/removing resistors during a specific period