Switch (4-Way) Symbol
Definition: The Switch (4-Way) symbol represents a double-pole double-throw (DPDT) intermediate switch used in North American residential wiring between two 3-way switches to enable control of a lighting fixture from three or more locations, featuring two pairs of traveler terminals (Traveler 1 In / Out and Traveler 2 In / Out); it is classified in IEC 60617-07 as an intermediate switch and in North American NEC practice as a four-way switch.
Also known as: four-way switch, intermediate switch (IEC/UK), DPDT crossover switch, middle switch, multiway intermediate switch.
What the Switch (4-Way) symbol means
The 4-Way Switch symbol denotes an intermediate switching device inserted between two 3-way switches in a multi-location lighting control circuit. It acts as a crossover switch: in one toggle position it connects T1-In to T1-Out and T2-In to T2-Out (straight-through); in the other position it cross-connects T1-In to T2-Out and T2-In to T1-Out (crossed). This alternating crossover action allows either end 3-way switch, or any intermediate 4-way switch, to toggle the light on or off independently.
In wiring diagrams, each additional 4-way switch symbol inserted between the two 3-way switches adds one more control location to the circuit. A three-location lighting system requires two 3-way switches and one 4-way switch; a four-location system requires two 3-way switches and two 4-way switches, and so on.
How to identify the Switch (4-Way) symbol
The 4-Way Switch symbol is drawn as a double-pole switch block with two input lines on the left (Traveler 1 In and Traveler 2 In) and two output lines on the right (Traveler 1 Out and Traveler 2 Out). In the schematic symbol, two movable contact arcs are shown — in one position both arcs connect straight across (parallel), and in the other position the arcs cross. Some representations show an X or crossover pattern inside the switch box to indicate the crossover function that defines this device.
Function in a circuit
A 4-way switch mechanically alternates between two connection patterns among its four traveler terminals: in position 1 it makes two parallel (straight-through) connections; in position 2 it makes two diagonal (crossed) connections. This crossover function ensures that any change in the traveler pair polarity (whether from a 3-way or another 4-way switch toggle) propagates correctly through the circuit to change the state of the load, regardless of which switch was last operated.
Standards: IEC vs ANSI
| IEC 60617 | IEC 60617-07 classifies this as an intermediate switch (also called an intermediate crossover switch). The IEC symbol shows two movable contacts each capable of connecting to one of two fixed contacts in a crossover pattern. It is called 'intermediate switch' in IEC / UK / European terminology. |
|---|---|
| ANSI/IEEE 315 | ANSI Y32.2 / IEEE 315 classifies this as a double-pole double-throw (DPDT) switch. NEC (NFPA 70) Article 404 uses the term 'four-way switch' for this device in North American residential wiring. The ANSI DPDT symbol shows two movable contacts with two fixed contacts each. |
| Key difference | IEC refers to this as an 'intermediate switch' (UK terminology); ANSI/NEC calls it a 'four-way switch' (counting the four terminals). The schematic symbol is a DPDT switch in both standards. The IEC crossover internal diagram explicitly shows the crossing connections; the ANSI DPDT symbol shows two separate SPDT switch sections sharing a common actuator. |
Terminals / pins
| Pin | Name |
|---|---|
| t1_in | Traveler 1 In |
| t2_in | Traveler 2 In |
| t1_out | Traveler 1 Out |
| t2_out | Traveler 2 Out |
Typical values
Typical ratings: 15 A at 120/277 V AC (NEMA residential), 10 A at 250 V AC (IEC). Four terminals: Traveler 1 In, Traveler 2 In, Traveler 1 Out, Traveler 2 Out. Toggle positions: 2 (straight-through and crossed). Conductor: 3-wire cables (black, red, white-reidentified as traveler) running between switch boxes.
Where the Switch (4-Way) symbol is used
- Long hallways requiring light control from three or more doors or entry points
- Large open-plan rooms with multiple entry/exit points each needing light control capability
- Staircase landings where three or more floors require independent light switching
- Hotel corridors with frequent room entry points needing multi-point lighting control
- Commercial warehouse aisles where lights must be controlled from multiple bay positions
- Multi-door garages where entry from house, side door, and main door all need switch control
- Theatre or auditorium stage lighting control circuits requiring switches at multiple positions
Example
In a three-location hallway wiring diagram, a 4-Way Switch symbol is inserted between two 3-Way Switch symbols. The Traveler 1 In and Traveler 2 In terminals of the 4-way connect to the traveler conductors from the first 3-way switch; the Traveler 1 Out and Traveler 2 Out connect to the travelers going to the second 3-way switch. Flipping any of the three switches toggles the hallway light on or off regardless of the current position of the other two switches.
Key facts
- The 4-Way Switch (North American NEC) is identical to the IEC 'intermediate switch' — a DPDT crossover switch that alternates between straight-through and diagonal connection of four traveler terminals.
- The symbol has four terminals: Traveler 1 In, Traveler 2 In, Traveler 1 Out, and Traveler 2 Out, with two movable contacts showing the crossover/straight-through switching action per ANSI Y32.2 / IEC 60617-07.
- A minimum of two 3-way switches are always required at each end of any multiway circuit; one 4-way switch is added for each additional control location beyond two.
- The 4-way switch has no Common terminal (unlike the 3-way switch) — all four terminals are traveler connections.
- In position 1 (straight-through): T1-In connects to T1-Out and T2-In connects to T2-Out; in position 2 (crossed): T1-In connects to T2-Out and T2-In connects to T1-Out.
- Smart 4-way switches (dimmer-capable multiway) may eliminate the need for traditional crossover wiring by communicating state wirelessly; one smart 3-way switch and add-on accessory switches replace the traditional 3-way/4-way combination.
- IEC 60617-07 symbol explicitly shows the crossover diagonal lines inside the switch body; ANSI DPDT symbol shows two SPDT sections with a common actuator.
Diagrams that use this symbol
- wiring a 4 way switch
- 4 way switch diagram
- four way switch diagram
- 4 way switch wiring diagram
- intermediate switch wiring diagram
- 4 way switch wiring schematic
- four way switch wiring diagram
- 3 pin rocker switch wiring diagram
Frequently asked questions
What does the 4-way switch symbol mean in a wiring diagram?
The 4-Way Switch symbol represents a DPDT intermediate switch inserted between two 3-way switches to enable control of a light from three or more locations. It alternates between straight-through and crossover connections of its four traveler terminals. Each additional 4-way switch in the circuit adds one more control location.
What does the 4-way switch symbol look like?
The 4-way switch symbol is drawn as a double-pole switch block with two input terminals on the left (Traveler 1 In, Traveler 2 In) and two output terminals on the right (Traveler 1 Out, Traveler 2 Out). Inside the switch body, an X or crossover pattern shows the diagonal switching action. In schematic notation, two SPDT switch arcs share a common actuator lever to represent the simultaneous switching of both poles.
What is the difference between a 3-way switch and a 4-way switch?
A 3-way switch is an SPDT device with one Common terminal and two Traveler terminals used at the ends of a multiway circuit. A 4-way switch is a DPDT crossover device with two Traveler-In and two Traveler-Out terminals, used only in the middle of a multiway circuit between two 3-way switches. A 3-way switch has no crossover function; the 4-way switch's crossover action is essential for three-or-more-location control.
Do you need 3-way switches with a 4-way switch?
Yes. A 4-way switch cannot be used alone — it must always be installed between two 3-way switches. The 3-way switches provide the feed and load connections at both ends of the multiway circuit; the 4-way switch(es) inserted between them provide additional intermediate control points.
What standard defines the 4-way switch symbol?
The 4-way switch uses the DPDT (double-pole double-throw) switch symbol per ANSI Y32.2 / IEEE 315, and is classified as an 'intermediate switch' per IEC 60617-07. Installation requirements for 4-way switch wiring in North America are covered by NEC (NFPA 70) Article 404.
How many 4-way switches can be used in one circuit?
There is no practical limit to the number of 4-way switches that can be installed between the two 3-way switches in a multiway lighting circuit. Each additional 4-way switch adds one more control location. In residential practice, circuits with more than three or four control points are unusual; dimmer-based smart switch systems are typically preferred for complex multiway circuits.
What terminals does the 4-way switch symbol have?
The 4-way switch symbol has four terminals: Traveler 1 In and Traveler 2 In on one side (connecting to the traveler conductors from one 3-way switch or previous 4-way switch), and Traveler 1 Out and Traveler 2 Out on the other side (connecting to the travelers going toward the next switch). There is no Common terminal on a 4-way switch.
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