What is the functional purpose of the "MS 2"...

🔍 Key Concepts

• Trace where the MS 2 contacts are physically located in the control circuit and what components they feed (H coil, L coil, UV coil, or contactor stages). • Compare the master switch position chart (which MS contacts close in each hoist/lower notch) with the speed/point sequence for the hoist motor. • Note how the first and second point hoisting/lowering are normally achieved in multi-speed/stepped-resistor hoist controllers.

💭 Think About

• When only the very first hoist position is selected, which MS contacts actually complete a path to any coil or contactor? Does MS 2 take part at this stage, or at a later point? • Follow the circuit from the power source, through UV and OL, down through MS 2: which coil(s) can be energized only when MS 2 is closed? What operating condition does that correspond to? • Does MS 2 have any connection to the UV coil circuit itself (for resetting), or is it clearly in the speed/point selection chain? What does that tell you about options C and D?

✅ Before You Answer

• Verify exactly which master switch positions (hoist and lower) show an "X" under MS 2 in the master switch chart. • Confirm whether MS 2 is in series with any of the point contactors (1A, 2A, 3A, 4A) or the H/L coils; that will tell you whether it is tied to first or second point operation. • Make sure the UV coil circuit path is understood: check if MS 2 is anywhere in that loop before choosing an answer that involves UV resetting.

What is the functional purpose of the "MS 2" contacts in the hoist controller circuit shown in the illustration? Illustration EL-0102

The "MS 2" contacts are used to select for "second point" hoisting and lowering

The "MS 2" contacts are used to select for "first point" hoisting and lowering

The "MS 2" contacts are not used in this particular application

The "MS 2" contacts are used for resetting the under voltage (UV) contactor

🔍 Key Concepts

💭 Think About

✅ Before You Answer