Ceiling mount occupancy sensor wiring question
I am trying to decipher what is expected in this electrical plan view in the attached photo in regards to the ceiling mount occupancy sensor.
Here is what I can make out: They don’t want you to just mount an occupancy sensor at the switch in the wall, because you can just swap that out for a regular switch and therefore bypass title 24 requirement for a motion sensor on a bathroom switch. They want you to have a wall mounted occupancy sensor that is wired into your lighting (only?, or the fan as well?) circuit, that way it will be less likely that you will go to the trouble of bypassing the occupancy sensor.
Can anyone explain to me what is happening here? Also looks like they are also calling out a switch with an occupancy sensor in box with the switches. None of this makes any sense to me.
Replies
When in doubt, ask the guy who signed the print.
It appears they want the sensor to control only the light over the sink.
I wasn't aware of Title 24 requiring this sensor.
It also appears the sensor is situated to also 'see' someone in the shower - where a sensor located at the switch location would be blind.
I agree ... confusing. Ceiling sensor, switch sensor, but what are the controlling??
Ask the designer for clarification. You could wire the light and the fan w/ the fan delayed for off time, I think.
I read that to say the occupancy sensor controls the feed to the switch for the fan and light. You need the switch on plus motion sensed to get the light and fan on.
If so that is a flawed design. I have motion sensors in my bathrooms and one in the kitchen. The problem in the bathroom is if you are not moving around a lot the light goes off and it probably can't see you in the shower at all.. I only use the motion sensor for low level "walking around" light. Task light is individually switched.
There is a difference between a motion sensor and an occupancy sensor. Particularly the dual technology occupancy sensors (very commone) that don't just sense motion, but sense your presence.
Without seeing the legend, I'm seeing two sensors in series to control the lights (and fan, maybe). You could do away with the switch mounted sensor, unless the bathroom is really that big and beyond the range of the ceiling sensor.