It is not uncommon for a circuit to be configured so that two wall switches in a single double gang box control two different light fixtures. The most basic circuit with only two wires at the switch.
Adding An Extra Light From A Light Switch
Twin light switch wiring diagram. Fully explained pictures and wiring diagrams about wiring light switches describing the most common switches starting with photo diagram 1. The second two way light switch is also quite easy to wire up. Multiple light wiring diagram. The source is at sw1 and 2 wire cable runs from there to the fixtures. The red wire is connected to the l1 terminal the black wire marked with red tape or red sleeving is connected to the l2 terminal and the earth wire is connected to the earth terminal. The cable coming from the first light switch is connected as follows fig 5.
The essence of the wiring configuration is for one hot feed wire entering the switch box to be split so that it feeds both switches which in turn feed hot wires in cables that lead out to two separate light fixtures. A switch with three wires could be used for a hall light with a switch at each end. The switch puts power out to one wire or the other like a valve for water that goes in two directions. The hot and neutral terminals on each fixture are spliced with a pigtail to the circuit wires which then continue on to the next light. Wiring a light switch diagram 1. This arrangement would typically be used in conduit and uses two wires between each switch.
Its possible that the switch you removed was one of the two that controls the non functioning light. It can also be used in domestic properties by using twinearth cable between the switches and 1coreearth from the switches to the ceiling rose. You identified your project to be about light switch wiring so you might find this information useful. This diagram illustrates wiring for one switch to control 2 or more lights. Two way switching 2 wires.
Gallery of Twin Light Switch Wiring Diagram
