Question 1 of 2707066636eed28f7522a1c51dd73

The winch shown in the illustration operates in any of the positions with the master switch in the 'lower' direction, but will not 'hoist' in any of the master switch hoist speed positions. Which of the listed faults could be the cause? Illustration EL-0102

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Question 1 of 27070
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Q

The winch shown in the illustration operates in any of the positions with the master switch in the 'lower' direction, but will not 'hoist' in any of the master switch hoist speed positions. Which of the listed faults could be the cause? Illustration EL-0102

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🔍 Key Concepts

• Study which master switch (MS) contacts are closed in ALL hoist positions but not required for lower. • Trace the control power path from the UV (undervoltage) relay through the master switch to the H (hoist) contactor coil. • Compare this with the path to the L (lower) contactor coil to see which MS contact is unique to hoist operation.

💭 Think About

• If the winch works in every LOWER speed, what parts of the circuit (including certain MS contacts) can you rule out as faulty? • Looking at the contact chart on the left, which one of MS 2, MS 3, MS 4, or MS 5 is in series with the hoist circuit for all hoist speeds, such that if its springs failed the hoist coil would never energize? • How do the limit switches LSH/LSL and the H/L selector contacts interact with the MS contacts—where is the single point that affects only hoist, not lower?

✅ Before You Answer

• Verify for each of MS 2, MS 3, MS 4, and MS 5 exactly which hoist positions (1–5) they are closed in—look for the one used in every hoist speed. • Confirm which MS contact is in the supply line that feeds the H contactor coil but not the L contactor coil. • Make sure that the fault you pick would still allow full operation in all lower positions, consistent with the symptom given.