Try reading the posts in the thread Archy instead of being swayed by arguments put forward by Domestic course trainees and Electrical Trainee sparks!! Sheesh..
Reasons, OK, clearly not definitive, but these reasons are why I personally feel it bad practice UNLESS required.
- The neutral in the back of the switch creates a possible confusion for untrained people who may interfere with installations (domestic) and if they replace switches etc could very easily create a dangerous situation that results in a fault or a potentially dangerous shock hazard.
- Extra cores in the back of a switch patress or back box creates a situation where it may be damaged by the simple task of putting the faceplate onto the patress/back box, thus causing a fault.
- Untrained people may use the neutral to install accessories onto the lighting circuit that should not be so installed, thus introducing a potentially dangerous situation that could lead to electrical faults, increased fire or shock hazards.
- Untrained people who replace switches for "decorative" units may inadvertently switch the neutral instead of the line conductor.
All of the above is especially real hazards when you have large premises with "complicated" switch arrangements caused by multiple stair runs and landings where they are switched at multiple points and perhaps multi-gang switches have switches fed from more than one circuit, as is highly probable on multi-level floored houses (town houses).
I can appreciate others see this different, but for me, as a fully qualified, apprentice trained, professionally accredited highly experience Electrical Engineer I will always see this as a bad practice way of wiring unless the switch concerned has a good reason for a neutral, such as it has an illuminated surround or neon of some type.
