All AC switches in home wiring have at least two hot leads. These may be in the form of terminals on the switch (either screw, push-in connections, or both), or wires permanently attached to the switch.
The most common switches are:
Basic switch (SPST) [old]
The simplist switch, in the pre-ground days had just two terminals
- hot in
- hot out
The wires to this switch should be black (most often) or red, or a combination of these. White wires can be used if they are marked as hot with tape or a marker.
This switch is also called single pole, single throw (SPST), because there is one line (pole) being switched and only one of the switch positions (throws) makes a live connection.
Basic switch (SPST) [new]
The simplist modern switch has three terminals
- hot in
- hot out
Same as old version but a green or bare wire goes to the ground terminal.
Basic 3-way switch
This switch is used when there are two switches used to control a device. It has four terminals
- hot (common)
- traveler 1
- traveler 2
The hot (common) of one of the 3-way switches is connected to the live load. The common on the other switch is connected to the device to be switched. The travelers of one switch are connected to the traveler terminals of the matching 3-way switch.
Basic four-way switch
This switch is used when there are more than two switches used to control a device. It has five terminals
- traveler 1 in
- traveler 2 in
- traveler 1 out
- traveler 2 out
This switch sits between two three way switches. Both travelers from one 3-way switch go to one side of the 4-way, and both travelers from the other 3-way go to the other side. The 4-way is never directly connected to the mains or to the switched device. Multiple 4-ways can be used if you want more than three switches on a line, but they are all between the original pair of 3-way switches.
These can be any of the switches listed above. These are characterized by having some feature other than basic switching, such as
- motion sensing
These have the same terminals as the basic switches, but usually add a neutral terminal (or white wire) to complete a circuit within the switch itself. A few active switches are designed to operate without a neutral. Check manufacturers' instructions.
There are numerous other, more complex switchtypes, including double pole, double throw, programmable, master, slave, etc. with various wiring requirements.
Your switch is a SPST switch, but it is active because of the PIR or timer functionality. Connect the black wire to the hot line in, the red wire to the device being switched, the white wire to the neutral in and the green wire to the ground in.