This post contains basic 3 Way and 4 Way lighting control Switch Loop Schematics.

With a "Complete" closed circuit, the Lamp is shown to be "On". If the Lamp is shown to be "Off", the circuit is open via one or more switches.

Schematics set #1; 3-Way Light Control Switch Loops:


Lamp "Off"


Lamp "On"


Schematics set #2; 3 / 4 Way Lighting Control Switch Loops:


Lamp "Off"


Lamp "Off"


Lamp "On"


Lamp "On"

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.

Please note:

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

Legend:
-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---

PART 2: 4-WAY SWITCHLOOPS; INPUT AT 1ST SWITCH



Lamp State: OFF



Lamp State: ON

Legend:
-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- 4-way switch location outlet box;

-E- Travelers (Black and Red), plus "Noodle" (White / Gray). 3 Wire Cable, or 3 Conductors for Conduit systems;

-F- Last 3-way switch location outlet box.

-G- 2 Wire Circuit (or Cable), out to Light Fixture outlet box.


---end of part 2---

PART 3: 3-WAY SWITCHLOOPS; INPUT AT LIGHT FIXTURE OUTLET BOX



Lamp State: OFF



Lamp State: ON

Legend:
-A- = Branch circuit input - 2 Wire Circuit / Cable. White wire (shown as Gray in these drawings) is Grounded "Neutral" Conductor;

-B- Light Fixture and outlet box. Note: Line Ungrounded "Hot" conductor is connected to the White wire on the outgoing 2 wire cable. If this was a Conduit system, do not use a White wire for this "Line Hot" part of the loop circuit, instead use a "Hot" circuit color - such as Black, Red, Blue, Brown, Orange, Yellow, Pink or Violet;

-C- 2 wire circuit to first switch location. May be 2 wire NM cable or 2 wire AC / MC cable. For Conduit systems, do not use White or Gray colored conductors anywhere in the complete loop!;

-D- First 3-way switch location outlet box;

-E- Travelers (Black and Red). 3 Wire Cable, or 3 Conductors for Conduit systems;

-F- Last 3-way switch location outlet box.


---end of part 3---

PART 4: 4-WAY SWITCHLOOPS; INPUT AT LIGHT FIXTURE OUTLET BOX



Lamp State: OFF



Lamp State: ON

Legend:

-A- = Branch circuit input - 2 Wire Circuit / Cable. White wire (shown as Gray in these drawings) is Grounded "Neutral" Conductor;

-B- Light Fixture and outlet box. Note: Line Ungrounded "Hot" conductor is connected to the White wire on the outgoing 2 wire cable. If this was a Conduit system, do not use a White wire for this "Line Hot" part of the loop circuit, instead use a "Hot" circuit color - such as Black, Red, Blue, Brown, Orange, Yellow, Pink or Violet;

-C- 2 wire circuit to first switch location. May be 2 wire NM cable or 2 wire AC / MC cable. For Conduit systems, do not use White or Gray colored conductors anywhere in the complete loop!;

-D- First 3-way switch location outlet box;

-E- Travelers (Black and Red). 3 Wire Cable, or 3 Conductors for Conduit systems;

-F- 4-way switch location outlet box;

-G- Travelers (Black and Red). 3 Wire Cable, or 3 Conductors for Conduit systems;

-H- Last 3-way switch location outlet box.


---end of document---

Scott s.e.t. posted 01.08.2003 17:41:00 PST