🔍 Key Concepts
• Carefully trace which master switch (MS) contacts are closed in the 4th point in LOWER on the diagram at the left
• From those MS contacts, follow the circuit to see which contactors (H, L, 1A, 2A, 3A, 4A) are energized or de‑energized
• Notice the difference between master switch contacts numbers (3,4,5,6,7,8) and the labeled contactors (H, L, 1A, 2A, 3A) so you don’t mix them up
💭 Think About
• On the master‑switch chart, which X’s line up under Lower – 4th notch for MS 1 through MS 8? List exactly which contact numbers are closed at that position
• Starting from the control power source, which closed MS contacts provide a complete path to energize each contactor coil (H, L, 1A, 2A, 3A)?
• At 4th point lower, is the circuit using high speed or low speed, and how many accelerating contactors (1A–3A/4A) must be picked up to get that speed?
✅ Before You Answer
• Double‑check which MS contact numbers are actually marked with X’s in the Lower–4 column before comparing to choices C and D
• Verify which contactor coils (H, L, 1A, 2A, 3A, 4A) have an unbroken path back to the return line at Lower–4 before comparing to choices A and B
• Confirm whether any previously energized contactors at lower points remain held in by their own auxiliary contacts or by the master switch when moving to 4th point lower