btw if your interested, in hotels and the like of commercial buildings - rarely seen on smaller scale
say you have a stairwell with 10 levels its more common to wire the lights together (dependent on single or 3 phase balanced) and then go through a latching contactor with a momentary push switch on each point rather than 2 2 ways and 8 intermediates
just incase anyone decides the 10 story block they own should have new lighting
btw, switches as we know them will be a thing of the past within the next 20-30 years with home automation and EIB systems becoming the norm
every switch is the same and linked to all other switches via a cat5 or EIB cable back to a lighting/dimming pack
each light in the house is on a radial back to the pack and each switch is given an identity, so the dimmer pack knows what switch where and what light its programmed to install
its taking over the commercial market, some clever stuff like fire alarms that can shut off the gas supply, charge the sprinkerlers, phone the fire brigade, put all the lighting on full lux, open all the electronicly locked doors close all the venting/extraction systems and what ever else is needed from lifting barriers to closing shutters, could even bring up the pictures from the closest CCTV camerato the activation point on the controlers screen so he knows whats triggered the alarm
great stuff ay
if anyone wants to know about it shout
