Smoke Detector Required in Elevator Pit?

7/19/2018

Daily Discussion question submitted from a member:

It seems that I must have missed something in the 23 years I've been in Code Enforcement. Since when has it been required for a smoke detector to be in the pit of the elevator? This is absolutely insane. We've had more nuisance alarms recently in new buildings. One is a 4 story nursing home, that the alarm has gone off 4 times. The alarm company changed the detector and it been good now. However there is still dirt, moisture, humidity, etc. All the things that smoke detectors don’t like.

I've looked and Googled it and have only come up with a heat detector within 24" of the sprinkler head, which I understand. I know smoke rises so why isn't the top of the shaft sufficient? I feel we are going backwards.

Discuss this topic here.

5 Comments

JOE

7/19/2018 01:24:20 pm

Heat detectors can be required for elevator pits, whenever a sprinkler is located within the elevator pit (NFPA 72-2016 Section 21.3.7).

There are exemptions for locating heat detectors in the pit now, however; if a waterflow switch and valve serve only the sprinkler within the shaft, with no time delay, then a heat detector is not required (NFPA 72-2016 Sections 21.3.3, 21.3.7, and 21.4.3).

I haven't had a smoke detector be required within the pit of an elevator - it would be difficult to test and service so there's naturally a reason to avoid locating smoke detector where it's not practical or necessary.

Jason Lupa, PE

2/4/2021 09:56:08 am

This is a common question usually raised in the field. The are no smoke detectors which meet the NFPA 72 or UL listing requirements for spacing to be installed in elevator pits. All electrical equipment within 4 feet of the pit must be NEMA rated for wet locations. The are no smoke detectors which meet the NFPA 72 requirements for spacing or the UL wet locations listings, to be installed in elevator pits NFPA [2016] 21.3.8.

If the sprinkler is above 24“ from the floor, then the WP pit heat detector is used to initiate the Firefighters’ Emergency Operation (FEO). Activation should only initiate alternate recall to position the cab further from the pit fire event. NFPA 72 [2016] 21.3.12.2 (3). This same function can also be achieved via a sprinkler water flow switch dedicated for the elevator pit (NFPA 72 [2016] 21.3.3).

James

10/7/2019 11:57:10 am

since 2007 code smokes have been removed from pits and replaced with heats in the pit as dust and the amount of space in the area of devices it too detrimental to it. If no electrical devices are in the pit and everything electrical is exterior of shaft or pit the only thing required would be a smoke in the shaft as there are electrical equipment on the elevator cab itself. If shaft is sprinkled then there would need to be a heat in the shaft with 2' of the sprinkler head. SInce there id the NFPA 72, NFPA 101, ASME17.1, Construction Code as well as locality Code, all would have to be referenced. but even after all this the AHJ has the Final decision. So if unsure always call the AHJ.

Benjamin ORegan link

11/19/2020 02:19:00 am

It seems the 2019 version of NFPA 72 requires detectors in elevator pits to be accessible. How would we achieve that? A fire rated trap door in the elevator shaft perhaps, or aspirated smoke detection?

Brian Scruggs

12/21/2020 05:42:53 pm

The word “accessible” is up to interpretation. Run the elevator to another floor and insert the elevator key in the door. You now have access.

Smoke Detector Required in Elevator Pit?

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