Very good question.
I have replaced an intermediate switch on the landing where the rocker switch failed.
The old intermediate plate had four connectors, supply and load (blue and yellow - old colours). Following the old switch wiring the system works but only if the intermediate switch is left switched on?
Believe I have a pole separator switch which includes earth separators and few, if any, replacement intermediate switches actually have the required four terminals!
Answered by: Rightman
Date published: 2016-11-13