Gang, means the number of switches in one block or switch panel.
Ways is not quite so straight forward or clear cut..... Basically it
means the number of different active positions which can be achieved by
one switch. A normal room light switch can achieve two positions, on or
off, but only one is active. Hence it is called a one way switch. The
type of switch commonly used for stair lighting is called a two way
switch, because it has two possible active positions. Both the 1 way
and 2 way switch are two 'position' switches.
The type of switch used in a photographers dark room, able to switch
between main lighting and safe lights, with a centre off position,
would be a 2 way three position.... 1 Safe light, 2 Off, 3 Normal
So, your boggest-standardest lightswitch controlling just one light is
"single gang"; the thing you have in a room where one plate has a switch
for the central light and a separate switch for the wall lights is "two
gang" or "double gang"; one with three switches on the one plate is "three
"Ways" is a separate concept, describing the number of distinct, active
current paths provided. For a simple on-off function, you need just one
current path which is either open or closed - that's a "1-way" switch.
When you want to switch from two different places, you need a "2-way"
switch, which connects one of two separate terminals to a common terminal
depending on the switch position. 1-way and 2-way is all you'll ever come
across in domestic mains switches, with the exotic exception of an
"intermediate" switch, used in between 2-way switches to give you
switching at more than two different placeses.
A 2-way switch can always be used in place of a 1-way: you wire to the
Common and L1 terminals, ignoring the L2 terminal. (Or to the Common and
L2 terminal, and then mount the switch upside-down ;-) Mass production
and stock-holding costs mean you'll often find only a 2-way flavour
HTH - Stefek
And just to add, as well as "ways" and "gangs", you also get "poles".
An additional pole is an additional switch that is affected by the same
switch mechanism. It is different from a gang, which is an additional switch
with an independent mechanism.
Light switches are usually single pole, so there is only one switch, which
should disconnect the live only. Switches for power circuits are now usually
double pole. This means that the one switch can turn off the live supply AND
Just a point of note for anyone confused - I've found that the "Select"
range from Screwfix is wired t'other way about - for one way switching
you wire common and L2 if you mount the switch with the legend "top" at
the top! Caught me out the first few times... but for a switch less than
half the price of the equivalent MK kit it's a minor inconvenience :-)
Martin Angove: http://www.tridwr.demon.co.uk /
Two free issues: http://www.livtech.co.uk/ Living With Technology
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