User Tag List

Results 1 to 7 of 7

Thread: Occupancy sensors in egress stairwells

  1. #1
    Join Date
    Jun 2014
    Location
    Madison, WI, USA
    Posts
    355
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Occupancy sensors in egress stairwells

    I have a question that is not covered by the National Electrical Code, but is mentioned in the Life Safety Code. I'm in charge of the facilities electrical of a large manufacturing facility and we are in the process of installing occupancy sensors throughout the building. It was brought to my attention that it is against code to put stairwell lighting on occ sensors.

    After doing a lot of research, I concluded that occ sensors are allowed in the path of egress for non-emergency powered lighting, as long as the sensors fail safe.

    What are your thoughts on this? I have been unsuccessful in finding any information in the cutsheets of the occ sensors we use indicating whether or not they fail safe (as in the relay fails closed).
    Tell me and I forget. Teach me and I remember. Involve me and I learn.

  2. #2
    Join Date
    Dec 2011
    Location
    Wisconsin
    Posts
    525
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by DrSparks View Post
    I have a question that is not covered by the National Electrical Code, but is mentioned in the Life Safety Code. I'm in charge of the facilities electrical of a large manufacturing facility and we are in the process of installing occupancy sensors throughout the building. It was brought to my attention that it is against code to put stairwell lighting on occ sensors.

    After doing a lot of research, I concluded that occ sensors are allowed in the path of egress for non-emergency powered lighting, as long as the sensors fail safe.

    What are your thoughts on this? I have been unsuccessful in finding any information in the cutsheets of the occ sensors we use indicating whether or not they fail safe (as in the relay fails closed).
    Wisconsin does not adopt NFPA 101 Life Safety Code.

  3. #3
    Join Date
    May 2011
    Location
    CA
    Posts
    45
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The IBC requires means of egress to be illuminated to 1fc min at walking surface at all times the building is occupied. So unless you have a secondary set of lights that will always provide 1fc min. then I wouldn't use on/off occ sensors in a stairwell, or egress corridor for that matter.

    What are you doing for emergency lighting?

  4. #4
    Join Date
    Nov 2018
    Location
    San Jose, CA
    Posts
    3
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If your emergency egress lighting are your standard fixtures either on an generator circuit or battery (integral or remote) powered during loss or power and also functions as “nite lighting” and are always on to comply with having the egress path lit to 1 fc during occupied conditions, then having the other lighting on a motion sensor would be fine IMO.
    If you do not have “nite lights” and all of the fixtures are on the same switch leg, then occ sensors would not allow you to comply. Although I’ve yet to see an inspector or fire marshall call someone on it in my 25 years of contracting.

  5. #5
    Join Date
    Nov 2018
    Location
    PA
    Posts
    1
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It's not against code exactly you just need to be able to bypass all local control in a emergency.

    Most manufacturers have UL924 listed bypass relays.

    Wattstopper ELCU-200
    Acuity Controls nLight nPP16 ER

    Are the ones I typically use.

  6. #6
    Join Date
    May 2011
    Location
    CA
    Posts
    45
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by vanpry View Post
    It's not against code exactly you just need to be able to bypass all local control in a emergency.

    Most manufacturers have UL924 listed bypass relays.

    Wattstopper ELCU-200
    Acuity Controls nLight nPP16 ER

    Are the ones I typically use.
    Couple things on the egress stairwell..

    -You cannot remove all lighting at any time the building is potentially occupied, paths of egress need to stay illuminated, regardless if the space is occupied.

    -this pertains to a building with an emergency branch for emergency lighting...I read 700.17 as saying spaces requiring emergency lighting must also have a normal lighting source. Just having one stairwell circuit from an emergency panel with an 924 bypass relay (ALCR) overriding a switch doesn't meet these requirements.

  7. #7
    Join Date
    Apr 2009
    Location
    Williamsburg, VA
    Posts
    6,042
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Putting occupancy sensors on stairwell lighting...

    My thoughts on this is that if for any reason somebody needs to use a stairwell, whether emergency or not, and it's not illuminated, and they are injured or worse, you are going to have absolutely no defense against that.

    While I can appreciate the move toward more efficient facilities, stairwell lighting comprises of maybe one thousandth of a percent of a facilities power use...

    Any gains are severely outweighed by installation cost and liability.

    Not to be overdramatic or apocryphal, however I could very well see this on an episode of Engineering Disasters.

    "Despite already having high efficiency LED lighting, they installed occupancy sensors in the stairwells, to save approximately $7 a year in power costs"
    Electricians do it until it Hertz!

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •