As a Follow-Up to a Member's comments per the above shown Switchloops, have compiled and posted Switchloop Schematics which include some "Crude" examples of Cabling.
These Schematics cover 3 and 4 way Switchloops - both in "OFF" and "ON" state, with AC Power entering the "First Switch Location" from the Branch Circuit, or from the "Light Fixture's Outlet Box".
Comments to these items may be discussed in the Four Way Switch
Thread, within the General Discussion area.
Further comments / questions as to the drawings should be directed to me via new topic or direct E-mail contact.
1: Either NM Cable, AC / MC Cable, or Conduit systems may be applied to these drawings,
2: Equipment Grounding Conductor(s) are not shown, but would be included to complete loop circuitry as "Normally Installed",
3: For Conductors with White Colored Insulation, the drawings display Gray Colored Conductors,
4: Line Voltage may be for any systems involved.
Now, on to the pictures!!! PART 1: 3-WAY SWITCHLOOPS; INPUT AT 1ST SWITCH
Lamp State: OFF
Lamp State: ON
-A- = Branch circuit input - 2 Wire Circuit / Cable. White wire (shown as Gray in these drawings) is Grounded "Neutral" Conductor;
-B- = 1st 3-way switch location outlet box. White "Noodle" is spliced and continues throughout loop;
-C- Travelers (Black and Red), plus "Noodle" (White / Gray). 3 Wire Cable, or 3 Conductors for Conduit systems;
-D- Last 3-way switch location outlet box.
-E- 2 Wire Circuit (or Cable), out to Light Fixture outlet box.
---end part 1---