Hint, if you want to make a switch opperate the oposite way up, identify which type of switch you have and swop the two right hand side terminals identified in the above diagram over.
Two way switching is most commonly found on stairs and landings, and long corridors. There are a few different methods of providing a 2-way switching circuit, these are shown below.
Please note that the some of the below diagrams have been drawn with the older cable core colours, others with the new cable colours.
As a rule for these diagrams, RED = BROWN ; YELLOW = BLACK ; BLUE = GREY ; BLACK = BLUE. The cores should be sleeved with the appropriate colour brown / red for live and black / blue for neutral.
You may find that the cables between the switches in your property have been connected with a different colour coding. This makes no difference to operation, as long as the colour at one switch matches that of the other(s),
Junction boxes need to be in an accessable location for inspection.
Chock block must be enclosed in fitting or in a suitable enclosure above ceiling and not exposed to heat from the lamp.
If a metal light switch is used, connect the earth wire to the earth terminal on the light switch and loop to the back box.
This method requires an extra terminal block to be placed inside the ceiling rose, light fitting or joint box;
The following diagram resembles how the top schematic diagram is wired, it should be noted that both the lamps must be on the same circuit otherwise what is known as a shared neutral will occur.
This method is most suited to conduit work, where the cables are single cores installed inside conduit or trunking. It can also be utilised, with adaption, in a domestic environment using standard Twin & Earth cable or double insulated single cores.
===== 2 Way Dimmer Switch =====
This is a 2 way dimmer switch, it can be used as one way or 2 way.
When being used for 2 way you should use all 3 terminals
when changing like for like The ~(with arrow) is the C terminal
L1 and L2 stay as they are
Also as this switch is metal you should connect an earth wire from the terminal on the PLATE (right hand side this picture) to the back box for the switch , ALONG with the earth wire that should already be there.
It is only possible to connect one of these type dimmer switches to each light, the other switch 2 way switch needs to be a normal two way light switch. There are however some types of dimmer switch on the market which can take a slave dimmer switch.