Elevator Recall Smoke Detectors

[nomorethan24v]

A few quick questions for anyone who knows the general national code for the following items, not their local codes please.

I've had trouble answering these following code questions with NFPA72. I'm sure the answers are in a code book that I do not have.

1) In a large elevator lobby, do your elevator recall smoke detectors count as coverage for the lobby? Or do there have to be separate smoke detectors for the lobby, and elevator recall.

2) I've heard a no more than five feet to the center of the elevator door rule, for spacing the elevator recall smoke detector? Could anyone confirm this, and where this can be found?

3) Location of the heat detector in the pit? Does normal spacing apply as you would place a detector under a floor as per NFPA 72 or is there something different?


Sorry for the lengthy post, I appreciate the help. And for the future, I'd love to know what code book contains the information I'm looking for, so I can keep it on hand.

 

[firetech]

Re: Elevator Recall Smoke Detectors

According to the NFPA 72 2002 Edition the section 6.15 applies.

1) & 2) 6.15.3.5 A lobby smoke detector shall be located on the ceiling within 21 feet of the centerline of each elevator door within the elevator bank under control of the detector.

Exception: For lobby ceiling configurations exceeding 15 feet in height or that are other than flat and smooth, detector location shall be determined in accordance with Chapter 5.

If a detector is installed within the elevator lobby and is within 21 feet of the centerline of the door then it may be used for the function of elevator recall. The 21 feet is given as the distance because of the .7 rule. Where normal detection would occur within a 15 foot radius of detection, the code allows for Hallway and Corridor circumstances where detectors distances between could be extended because the hallway walls are closer to the detector than 15 feet, this is not to exceed a maximum of 42 feet between detectors. However not all jurisdictions subscribe to this idea, so check with your AHJ and/or Fire Inspectors Office. So you may be required to be within 15 feet of the centerline of the door. But any detector attached to the fire alarm system should be acceptable for use for elevator recall.

3) This is a complicated answer. This takes into account ANSI/ASME A17.1 Safety code for Elevators and Escalators.

6.15.4.2 If heat detectors are used to shut down elevator power prior to sprinkler operation, they shall be placed within 2 feet of each sprinkler head and installed in accordance to chapter 5.

If the heat detector is installed for the shut down of elevator prior to elevator operation it shall have both a lower temperature rating and a higher sensitivity as compared to the sprinkler.

The best way to be sure of this circumstance is to check with the elevator mechanic, and the AHJ.

If you need further assistance just let me know.