I’m doing an electrical plan and trying to understand how photo/motion/occupancy sensors work in order to make the correct specifications.

I’ve heard that you would need a switch just for maintenance purposes even though the switch wont be used much.

For example, in the bathroom there’s going to be 3 kinds of lighting
1. vanity lights / sconces
2. fan/light combination over the toilet
3. shower light.

Questions:

1. Can there be just one switch connected to the entire combination while each fixture independently turns on with motion, not all at once?

2. Can there be a separate turn-on switch for the fan so that it turns on only when the occupant wants it? Or should there just be a separate light fixture instead of the light/fan fixture combo?

3. Is this all too complicated for the electrician?

4. Would photo/motion/occupancy sensors escalate the installation cost too much?

 

In commercial spaces, you do need a disconnect for lighting but you do not need one in a dwelling. However, the disconnect requirement in commercial is easily satisfied by liner disconnects in the fixtures and other options so you rarely have to install a special switch.

Yes, You could master/slave the lights. The master switch will need to be activated first before the slave switches can be activated.

Yes, they should be able to switch the fan and light seperatly.

Not really, it might cost more than just a standard switching.

It will all depend on the type of switches needed. A simple LED Occ switch runs about $25 for the switch while a 0-10v occ switch/dimmer is about $85 for the switch. Pluss installation.