How To Perform Elevator Recall...

[Fire Alarm]

OK, this is a fire alarm question. I have not yet had to interface a fire alarm system with an elevator and I have a question that hopefully you guys can help me with.

If the smoke detector on the first floor lobby goes into alarm, the elevator needs to go to the alternate floor. If a smoke detector on any other floor latches, the elevator needs to go to the primary floor...

I'm assuming that this is done with relays integrated into the base of the detector and the dry contacts on these relays have wires that travel to the elevator equipment room where the elevator tech makes the actual connection to his control box...

BUT. NFPA 72 says you can have no more than 3' of unsupervised wire, so the relays and wires-to-the-equipment room idea seems like a code violation.

What is a code compliant way to control the elevators? Does this require an addressable system with a special addressable relay in the elevator equipment room?

Any help would be greatly appreciated.

 

[iwire]

I have seen it and done it both ways, from the smoke bases on older systems and with addressable modules located as close as practical to the elevator control tie in.

As far as I can remember the interconnect wiring was unsupervised, which means either their are exceptions or I just learned something new.

The last one I did with smoke bases was only a year or two ago, it was inspected and passed. (Old building, new elevator)



By the way, I like that avatar.

 

[Firegeek]

If the system is ZONED (not addressable) then the recall smokes have to be FOUR-WIRE with relays. Therefore, the wire from the relay to the EMR will be supervised by the smoke detector. If the wire loses continuity, the smoke will go into trouble.

Since non-addressable panels are now higher-priced, it is likely that you will use an addressable system. This is easier!

Map the lobby smokes to the relay modules in the EMR. The relays are inherently supervised.

NOTE, in some condo conversions the elevator opens directly into a dwelling unit. This requires the recall smoke (addressable) to be programmed for SUPERVISORY to prevent false alarms. This programming change must be pre-approved by the AHJ to avoid hassles.

BTW, I have NEVER had an inspector (Fire or Elevator) question the supervision of these wires.

 

[iwire]

BTW, I have NEVER had an inspector (Fire or Elevator) question the supervision of these wires.

I assume your not required to provide UL certified compliance?

 

[MichaelGP3]

There are many varied ways to accomplish this, depending...

There are many varied ways to accomplish this, depending...

on the answers to the following questions.....

1.) New building or retrofit?

2.) What brand & model of fire alarm panel?

3). Are there any local codes governing the work that are relevant to the work being performed?

4.) Does a detail on the approved plans or a section of the specification address this?

One method that hasn't been mentioned on a zoned system (class "b" smokes would be okay, contrary to what was stated earlier) would be to use a relay that was listed for use with the panel connected to a supervised control output zone. The coil of the relay would need to be polarized with a diode, and wired so that removing the relay from the relay base would cause a trouble at the fire alarm panel. The relay would be installed in the elevator machine room, within 3 feet of the equipment. Two relays on different zones are needed to accomplish alternate floor recall.

 

[Fire Alarm]

Wow. Thanks everybody. What a great forum. Thanks again!

 

[DM2-Inc]

NFPA 72 and ASME 17.1

NFPA 72 and ASME 17.1

The requirements for elevator recall have gotten more elaborate over the years. There is however little difference between the 2002 and 2007 edition of NFPA 72. There is more to it than the smoke detectors in the elevator lobbies however. Some things to consider:

1. The definition of the "Primary Floor" will be the floor that the fire department enters on. This can be an issue if the building is on the side of a hill (It's happened to me).

2. Primary (typically 1st floor) elevator lobby smoke to recall to alternate floor (usually 2nd floor).

3. Secondary (typically 2nd floor) elevator lobby smoke to recall to primary floor (usually the 1st floor).

Now...I know what your thinking...what happens if the primary floor gets an alarm, elevator goes to the secondary floor, and then the secondary floor goes into alarm...well the truth is the code is silent on this issue, but generally speaking you'll leave the elevator at the secondary floor.​

4. If there is a sprinkler head in the elevator pit, you'll have to place a heat detector with in 2' of the head. You should note that if the elevator and shaft is of non-combustible construction you don't need the sprinkler head, however many sprinkler companies will install it anyway because it cheaper to install it than ask if the construction is non-combustible. The smoke detector is then required by default (I'll explain later).

5. A elevator lobby smoke detector activates "Phase 1" elevator recall. The elevator control panel handles the hard stuff but it will cause the "Fireman's Hat" lamp in the elevator to turn on steady.

6. The elevator machine room needs both a heat detector and a smoke detector.

7. If the elevator machine room smoke activates, you'll need to send a distinct signal to the elevator control. This same detector is to also initiate "Phase 1" recall (i.e. recall the elevators) to an alternate floor depending on what floor the machine room is on (usually the bottom most floor). The elevator controls will cause the "Fireman's Hat" to start flashing. This is to warn any fireman using the elevator that there is smoke in the machine room and the heat detector may go next, which will cause the elevator shut trip to activate. This in turn will shutdown the elevator all together trapping anyone inside, event the firemen.

8. If the heat detector in the pit, top of shaft, or machine room trips, the fire panel operates the shut trip circuit and shuts down the elevator.

9. You need to supervise for presents of 120 VAC on the shut trip circuit with a 120 VAC relay that's normally energized. You'll monitor the contacts with a fire alarm circuit.

10. Elevator detectors (Lobby, Machine Room, etc.) aren't require to be considered a "Fire Alarm" (i.e. sound all the bells and horns in the place). They're to be considered a "Supervisory Signal" (i.e. similar to a valve tamper switch), unless the AHJ says otherwise.

11. All elevator lobby smoke detector are to be connect to a Listed fire panel. If the building doesn't require a fire panel than this panel will be labeled "Elevator Recall Panel" and must be located where it can be easily seen (i.e. lobby).

12. The 3' rule is actually difficult to enforce. What's required is that the circuit from the control panel to the relay be either supervised or be normally energized (i.e. fail safe). There is also a statement that either the relay be with in 3 feet of the device it controls or the circuit that's controlling the device. When you think about it, you could run a shut trip circuit all over the building and then finally to the relay and there would be no way for the relay to NOT BE WITH IN 3' OF THE CIRCUIT. After all it has to land on the contacts.

There's more to this story but for now you should get the picture.

Regards,
Dan Marr.