Monday, August 1, 2016

4 Way Switch Wiring Methods

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If you only need one switch to control a light, then you would use a single pole switch.
If you need 2 switches to control a light then you would use two 3way switches.
If you need three switches to control a light then you would use two 3ways with one 4way.
If you still need more switches just add 4ways. Need six switches? Use two 3ways with four 4ways.

➳ Weather you use one 4 way or more, the 4 way will not work without two 3 ways.

A 4way switch has 2 "IN" terminals and 2 "OUT" terminals. They are identified on the switch with the words "IN" and "OUT" or there might be 2 marks identifying a pair of terminals as either "IN" or "OUT" The 2 traveler wires from one 3way are connected to the 2 "IN" screws or the 2 "OUT" screws but never one traveler to "IN" and the other to "OUT"

















            S4 Method #1     Basic 4Way                     

This is the best and easiest method of wiring 4 way switches.
If you only learn one 4 way method, learn this one.
Rating  Excellent A+

The most simple and trouble free 4 way method.
Level  Intermediate. It is also called a "Plain Jane 4 way" 

Description  Same as 3way Method #1 but add a 4way switch into the traveler wires between the two 3ways.  A 2 wire (14/2, 12/2) feed is pulled from the nearest source of power like a receptacle to the first 3way switch box. Then a 3 wire (14/3, 12/3) is run between switches, from the first 3way to the 4way to the second 3way. Finally a 2 wire switch leg is pulled from the last 3way to the nearest light and then to any other lights that are supposed to come on with these switches.


L1 = hot, C = common, T = traveler terminal, IN = the IN terminal on a 4way switch, OUT = the OUT terminal on a 4way, and N = neutral.



L1  C1 ➪ ➪ ➪  9 ➪ C10 ➪ 11 ➪ 12 ➪ N
Current begins at L1 and flows through the wire to C terminal on the first 3way switch. Inside the switch it flows through the switch blade (purple) from C1 to 2. It then leaves the 2 terminal and follows the (red) wire to IN terminal 4 on the 4way switch. Inside the 4way current moves through the (purple) switch blade from 4 IN to 7 OUT terminal (never IN to IN or OUT to OUT) It leaves the 7 OUT terminal and follows the black wire to the 9 terminal on the last 3way switch. Inside the 3way it flows from 9 to 10 Common. It then leaves the 10 C terminal and follows the (black) switch leg wire to the 11 terminal on the light where it connects to a small point on the base shell of the light bulb. Inside the light bulb current flows through the filament wire to the base shell where it connects to terminal 12. From 12 current heads back to the source through the neutral wire to N.

The part that is not shown is how current continues from the N (neutral) to a transformer coil, through the coil to L1 (hot) where it starts all over again.
As mentioned at the top, it is important to note how the 3way and 4way terminals make connections in different positions of the switch. In 4ways In's connect to OUT's but never to each other (unless the switch is defective).

In 3 ways Travelers connect to the Common but never to each other. Refer to the drawings above;
On the S4; 4IN connects to 6OUT or 7OUT but never the other IN number 5
5IN connects to 6OUT or 7OUT but never the other IN number 4
6OUT connects to 4IN or 5IN but never the other OUT number 7

7OUT connects to 4IN or 5IN but never the other OUT number 6

On the S3; 10 Common connects to 8 Traveler or 9 Traveler but 8 and 9 never connect together.




         S4 Method #2    Dead End 4way With Extended Switch Leg           

Rating  Above Average B  
This method is commonly used by professional electricians
Level  Intermediate.
Description   Power and switch leg at one 3 way and the dead end of a 3 wire at the other 3 way.  When wiring a dead ends you have a choice of which wire to extend over to the common on the dead end 3way switch:
- either extend the black switch leg from the light 
- or extend the black hot (L1).
In this example the switch leg is extended over to the common on the dead end 3way.



























         S4 Method #2.1      Dead End 4way With Extended Hot            


Rating  Above Average B  
Level  Intermediate
Description  Power and switch leg at one 3 way and the dead end of a 3 wire at the other 3 way. The travelers are the same as S4 Method #2, the neutral is the same, the only change in wiring is the hot is extended over to the dead end 3way's common instead of the switch leg. Compare the L1 wire in this method with  the L1 wire in S4 Method #2 above.

































           S4 Method #3      Double Dead End 4way            

Rating   Average C+
Level  Advanced Also called a "Switch Leg and Feed at the 4way"
Description  Everything is pulled to the 4way switch box;
the feed, the switch leg from the light, a 14/3 from one dead end 3way and
another 14/3 from the 2nd dead end 3way.
The hot is extended to one 3way and the switch leg is extended to the other 3way.






















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