what is "Alternate switching"?

Thread Starter


Joined Sep 13, 2013
Hello everyone,

I'm looking for the meaning of "alternate switching".

What is it? and How it is used? I'm trying to tranlate the meaning of that into my language.

"Alternate switching is mostly used in the lighting of staircases and long corridors."



Joined Oct 2, 2009
My guess is that it is what is known as "3-way switch" in the electrical trade.

It consists of two single-pole double-throw (SPDT) switches that are located at two ends of a long hallway or at the top and bottom of a staircase. With two switches a person can control the light fixture from either location.

This is required by building code for stairways leading to a basement or cellar.


Joined Dec 13, 2013
another use for "alternate switching" is pumps. two or more pumps are used in paralell,with a switch that selects one then the other. supposed to prevent pump failures. the switch also turns both on if needed. used for sewage lift pumps, and in reality, causes both to wear out at the same time.