The term ‘Multiway Switching’ signifies the linkage of more than one electrical switch to regulate an electrical appliance from different locations. For example, if you want to design the wiring of a big Hall-room so that the whole lighting can be controlled from different access routes. Even if the lighting of a Staircase to be controlled equally from different floors, multiway switching will serve the purpose.
This genus of switches definitely brings automation by analog means. You can emulate many circuit diagrams to create convenient control tactics. There’s even a way that you can get two switches from two distinct locations to turn ON/OFF a switch. In other words, it’s a slick, convenient, and reliable way to bypass microcontrollers and other complicated electronics.
Types of Multiway Switching
Using a normal 1 Way Switch, you can turn on/off any device from any single location only. It has the most simple mechanism where through clicking the switch you usually ‘make’ or ‘break’ any circuit. But in case of multiway switching, you can perform the task of making or breaking the circuit from more than one location employing multiple switches.
Multiway switching can be of 3 types. Their names vary from place to place. Generally, they are termed as: i) 2 Way Switching, ii) 3 Way Switching and iii) 4 Way Switching.
2 Way Switching
The switching mechanism using which you can employ two switches to control one output device is known as 2 Way Switching. Changing the toggle position of either switch, you can separately control the appliance.
This arrangement is commonly used in long hallways with a switch at either end or in stairways placing one switch upstairs and the other switch downstairs.
Why is it named 2 Way Switching?
Using the normal on/off switch, you can either connect or disconnect the circuit, i.e. it has only one combination for making the connection. The name ‘2 Way Switching’ was assigned because you can have 2 different combinations for making or breaking the circuit.
What is a 2 Way Switch?
For 2 way switching, you should use two 2 Way Switches (as shown in Figure – 1.1). It is also known as ‘3 Way Switch’ in America. This kind of switch has three ports- 1 Common port (marked as ‘Com’) and 2 Terminal ports (marked as L1 and L2). This type of switch is also known as SPDT (Single Pole Double Throw) switch.
2 Way Switching Mechanism
Following a specific color code, connect the hot wire to the common port of one switch (S1-Com). Connect another wire between the common port of the other switch (S2-Com) and the bulb. Then make the interconnection between the alternate traveler ports, i.e. connect S1-L1 to S2-L1 and S1-L2 to S2-L2. Then connect the neutral wire to the bulb.
For 2 types of state of either toggle, you can get electricity live through the circuit, which can be separately made or broken causing an alternate change of either switch. For this reason, this type of switching is known as 2 Way Switching.
3 Way Switching
The switching mechanism using which you can employ two switches to control one output device is known as 3 Way Switching. Similar to 2 Way Switching, by changing the toggle position of either switch, you can separately control the appliance.
But apart from that, you can also join the Live wire directly to either switch in this case as the switches used in this case have separate grounding wire connecting screws. This arrangement is commonly used in long hallways with a switch at either end or in stairways placing one switch upstairs and the other switch downstairs.
Why is it named 3 Way Switching?
The term ‘3 Way Switching’ indicates the fact that you can arrange the switch toggles by three different ways to make the connection live: i) both toggle levers up, ii) both toggle levers down, iii) the toggle levers in opposite positions.
What is a 3 Way Switch?
For 3 way switching, you should use two 3 Way Switches (shown in Figure – 3.1). This kind of switch has four ports- 1 Common port (marked as ‘Com’), 2 Terminal ports (marked as T1 and T2), and 1 Grounding port(marked as ‘Gr’). This type of switch is also known as SPDT (Single Pole Double Throw) switch, just a separate Grounding pin is added to it.
N.B.: 3 Way Switches used for this sort of switching are quite similar to the 2 Way Switches, but it additionally has a grounding wire connecting pins with each switch.
3 Way Switching Mechanism
For 3 Way Switching, you should take two 3 way switches. You can have three different patterns for making the connection live. The arrangements are discussed ahead.
Connection Pattern 1
This pattern is similar to the 2 way switching pattern. Following a specific color code, connect the hot wire to the common port of one switch (S1-Com). Connect another wire between the common port of the other switch (S2-Com) and the bulb. Then make the interconnection between the alternate traveler ports, i.e. connect S1-T1 to S2-T1 and S1-T2 to S2-T2 (as shown in figure – 4.1). Then connect the neutral wire to the bulb. Here for 2 types of state of either toggle, you can get electricity live through the circuit, which can be separately made or broken causing an alternate change of either switch.
Connection Pattern 2
This pattern is also known as ‘Alternate 3 Way Switch Wiring’. Following a specific color code, connect the live wire to one traveler ports of each switch (S1-T1 and S2-T2). Then make the interconnection between the common ports of the switches, i.e. connect S1-Com to S2-Com.
Then connect the left traveler port of both switches (S1-T2 and S2-T1) to a connecting wire and connect the wire to the bulb (as shown in figure – 4.2). Then connect the neutral wire to the bulb. Then make grounding of both the switches. This alternate connection can be made possible only because of the grounding facility of the switches.
4 Way Switching
The switching mechanism using which you can employ more than two switches to control one output device from different locations is known as 4 Way Switching. You need to use two 2 Way Switches (shown in ‘figure – 1.1’) and any required number of 4 Way Switches/Intermediate Switches (shown in ‘figure – 5.1’) or DPDT relays (shown in ‘figure – 5.2’) to complete a 4 Way Switching wiring.
This arrangement is generally used in big hall-rooms with switches at desired places convenient to access or in multi-storeyed stairways placing the loads at series and employing more than two switches at desired floors.
Why is it named 4 Way Switching?
This is more commonly known as ‘Intermediate Switching’. Having intermediate switches or DPDT relays in the middle, any of them can divert electricity by 2 pairs of directions for both of their states. For this reason, it is known as ‘4 Way Switching’.
What is an Intermediate Switch and a DPDT Relay?
To glue your multiway switching ideas intermediate and DPDT switches are quite unavoidable. Creative minds can’t and won’t leave them alone.
4 Way Switch/Intermediate Switch
A ‘4 Way Switch’ (also known as ‘Intermediate Switch’) is a technically designed DPDT (double pole double throw) switch. This mechanical module can cause crossing-over connections between the input and output through the switch having four external terminals.
The toggle changes position from parallel to crossed without having internal contact. This type of switch has two pairs of ‘traveler’ terminals on either side where one pair acts as Poles and the other pair as Throws (as shown in ‘figure – 5.1’). The throws act as common for both the pole connecting toggles.
You can however reinstate an Intermediate Switch by adding a separate DPDT relay. A DPDT relay is an electromagnetic device which connects two circuits magnetically and separates them electrically (shown in ‘figure – 5.2’). But we should apply a low voltage source to it for controlling its transposition mechanism.
4 Way Switching Mechanism
For 4 Way Switching, you should take two 2 way switches that are connected at the front and the end. Connect the Live wire to a 2 Way Switch and connect the load with the other 2 Way Switch.
Place any required number of intermediate Switch between them and connect them as per figure – 6.1 (here connection of three switches is shown).
2 Way Switch vs 3 Way Switch
Quantitatively, multiway switches are different. Significant contrasts are found, qualitative too, between 2 way and 3-way ones.
Both 2 Way and 3 Way switches are SPDT switches. But 3 Way switches have an extra pin called ‘Grounding pin’, which is not present on 2-way switches.
Screws and Load
2 Way Switches have 3 screws, whereas 3 Way Switches have 4 screws. But irrespective of that, in both cases, you can employ 2 switches to control the load.
You can find 2 possible arrangements for making a 2 Way Switching mechanism live, and in the case of 3 Way Switching you can find 3 possible arrangements
Live Wire Connectivity
In the case of 2 Way Switching, you cannot connect the Live wire with both the switches separately, but you can do so in the case of 3 Way Switching (which is also known as ‘Alternate 3 Way Switching’)
You need to use 2-wired cable both between the switches and between the light fitting and a switch for 2 Way Switching. But in case of 3 Way Switching, you need to use a 3-wired cable between the switches and a 2-wired cable between the light fitting and a switch.
3 Way Switching is safer than 2 Way Switching as the facility of grounding is found in it for both the switches separately.
3 Way Switching is costlier than 2 Way Switching as the switches cost more, both 2-wired and 3-wired cables are needed, and as about 5 wire connectors are needed for installing a 3 Way Switching.
3 Way Switch vs 4 Way Switch
Though a 3 Way Switch and a 4 Way Switch are quite similar, some aspects have driven them poles apart. A relative comparison will surely make it clear.
In the case of 3 Way Switching you ought to switch by SPDT mechanism, but in case of 4 Way Switching you should use switches of both SPDT and DPDT mechanism.
Both 3 Way and 4 Way switches have 4 screws. But in the case of a 3 Way switch, one of the screws is a grounding screw, whereas in the case of a 4 Way switch you will find 2 pairs of traveler screws.
In the case of 3 Way Switching, you can employ 2 switches to control the load. Whereas 4 Way Switching allows an indefinite number of switches for controlling a single load
Hot Wire Connectivity
In the case of 3 Way Switching, you can connect the Live wire with both the switches separately (which is also known as ‘Alternate 3 Way Switching’), but you can connect the Live wire with the Intermediate switch in the case of 4 Way Switching.
3 Way Switching is safer than 4 Way Switching as the facility of grounding is found in it for the switches separately.
4 Way Switching is costlier than 3 Way Switching as the switches cost more and as more cables are needed to install more switches for instating a 4 Way Switching.
All of 2 Way, 3 Way, and 4 Way switching are efficient for household wiring. The choice rests on you and your wiring condition. But for normal wiring, it’s better to use the regular on/off switch as it will make your building wiring cost-efficient.
You should follow the regional color code for the wiring purpose. Remember, electricity is dangerous and can be fatal. You should be qualified and competent before carrying out any electrical work. Hiring an expert is the last piece of counsel we leave you with.