Two way switch connection

TWO-WAY LIGHTING CIRCUIT

                                                     A lighting circuit is often used on staircases so that one can switch off the downstairslight from upstairs, or vice versa.   

In this circuit, the switches can have two positions, either of which can light the lamp. Suppose switch 1 is in the upper position, and switch 2 is in the lower position,

as illustrated, there is no circuit, so the lamp is out.

If switch 2 is operated a circuit is established, and the lamp lights. Now if switch 1 is operated the lamp goes out. The two wires between switches 1 and 2 are called ’strappers’.

Intermediate lighting circuit

When it is required to control the lighting in a long corridor or staircase with several landings, it is desirable to arrange for lights to be switched on and off at several points. In this case intermediate switches should be used.

If the two wires between the switches A and B as illustrated (the strapping wires) were reversed, a circuit would be established and the lamp would light.

The intermediate switch carries out this reversal of the strapping wires. Any number of intermediate switches may be installed.

   Conversion of one-way lighting circuit to two-way switching

It is sometimes necessary to modify lighting circuits controlled from one point.   

Consider an existing one-way circuit such as that previously illustrated. To convert    it to a conventional two-way circuit, either the switch feed, or the switch wire mustb beremoved, and replaced by a conductor going to another switch position. "rhis alteration must be made either at the lamp or at the consumer unit.

“rhis can be avoided by using the circuit illustrated. Two-way switch control can be    achieved by replacing the original switch by a two-way switch connected as illustratedand by running three new wires to a two-way switch at the new control position.

Stairs case wiring system

  In the above picture it is stated that a bulb is operated from two places by  The 2 way switch is used. 

   Now consider this circuit diagram. In this case you can see that circuit is complete and bulb is ON. Suppose you want to OFF bulb from the upper switch at top of stair, simply Switch OFF the switch then circuit will break and the bulb will be OFF. You can switch ON the bulb again to switch ON this Switch. In other words you can OFF and ON bulb from upper switch at the top of stair. Obviously; you can do same from the upper and bottom switch, so let’s see how we can do that from that switch at the bottom of stair.  

                    Now return to circuit again in the pic, In this case you can see that circuit is complete and bulb is ON. Suppose you want to OFF the bulb from the lower switch at bottom of stair. Simply OFF the switch, then again circuit will break and the bulb will be OFF. You can switch ON the bulb again to switch ON this Switch.

                   This is a stair case circuit diagram by which we can control a bulb from two different places.We can switch OFF and Switch ON the bulb from both switches at the same time. in other words we can control (OFF or ON) the bulb from upper and lower switches.