14.1 Manual Stations, Waterflow, Supervisory, Duct, and CO
Key Takeaways
- Manual fire alarm boxes are dual-action or single-action initiating devices; ADA/ICC A117.1 and commonly taught NFPA 72 practice put the operable part 42–48 inches above the finished floor, and stations do not belong in locked rooms without AHJ acceptance.
- Waterflow is an alarm-initiating sprinkler input; vane switches serve wet pipe and pressure switches serve dry, preaction, and deluge work; a retard commonly taught in the 30–90 second range ignores pump surges while real one-head flow still has to alarm.
- Supervisory points report off-normal protection features — control-valve tamper, low or high air, low temperature — not a fire and not a wiring trouble.
- Duct smoke detectors use listed sampling tubes and typically drive HVAC shutdown or fan control; the input may be supervisory or alarm according to the approved sequence, and they do not replace area detection.
- Carbon monoxide on a fire-alarm control unit is occupancy- and code-driven; New York dwelling CO alarm rules are not a commercial system-CO spacing table, and system detectors are not the same product as single-station dwelling alarms.
The New York Department of State (DOS) Security or Fire Alarm Installer written exam treats fire technology as its own block of the 81-hour course. 19 NYCRR 196.8 Module 4 is 15 classroom hours. Chapter 13 covered smoke and heat. This section covers the other initiating devices that still land on the same control unit: manual fire alarm boxes, waterflow switches, supervisory devices, duct smoke detectors, and carbon monoxide (CO) inputs where occupancy rules require them.
Independent OpenExamPrep teaching here is study help for that sitting. It is not a DOS publication, not an NFPA reprint, and not an FDNY Certificate of Fitness course. The DOS bulletin bases code questions on the New York State Uniform Fire Prevention and Building Code and NFPA standards. The 2025 Uniform Code (effective December 31, 2025) adopts fire-alarm installation through the Building Code and Fire Code of New York State, which reference NFPA 72. The bulletin does not print edition years; do not claim that it lists NFPA 72 (2022). On the job, those referenced practices still govern how you mount a pull station and how you program a tamper switch.
Manual fire alarm boxes
A manual fire alarm box (pull station) is an initiating device a person operates to report a fire. It is not a detector and it is not a horn. Product listing is commonly discussed under UL 38. On a conventional initiating device circuit it looks like a contact closure. On an addressable signaling line circuit it is an addressable station or a monitor module. Either way, the control unit must receive it as an alarm, not as a trouble and not as a supervisory, unless the approved sequence of operations says something unusual for a special application the AHJ has accepted.
Dual-action versus single-action
Single-action stations operate in one motion — typically a downward pull on a handle. Dual-action stations require two distinct motions, such as lifting a cover then pulling, or pushing in then pulling down. Dual-action hardware is widely specified because it reduces accidental alarms from backpacks, carts, and horseplay in corridors and stairwells. Dual-action is not a license to hide the station or to mount it out of reach.
Protective covers and “stopper” cabinets are a separate listing problem. A cover that is not part of the listed assembly, or that delays operation, can change how fast a person can start an alarm. Many authorities having jurisdiction (AHJ) require approval before you add that hardware. Teach the exam idea: the station must still be operable by the public it is meant to serve, without a scavenger hunt for a key.
Height, location, and locked rooms
ADA Standards and ICC A117.1 are commonly taught together with NFPA 72 on operable-part height. The teaching range you should remember for a manual station is 42 to 48 inches above the finished floor to the operable part — the handle or the part a person actually uses — not to the top of the backbox and not to a decorative sign above the device. That range is a reach-range practice so a person using a wheelchair can start an alarm. It is not a candela table, and it is not a New York-only inch schedule invented for this license.
Place stations in the natural path of egress, commonly near exits and exit-stair doors, unobstructed, and conspicuous (typically red). Do not install the only station for an area inside a locked room, a telephone closet, or a manager’s office unless the AHJ has accepted that arrangement for a documented reason (for example a constantly attended location with an accepted alternative). A station the occupants cannot reach during a fire is not serving as a manual fire alarm box.
Travel-distance and “how many exits need a box” rules live in the adopted building and fire codes plus NFPA 72 application chapters. Learn the idea for the closed-book exam: enough stations that a person can find one without hunting, mounted at an accessible height, not hidden. Do not invent a unique New York spacing grid beyond that commonly taught 42–48 inch operable-part range.
Waterflow switches
A waterflow switch reports that water is moving in a sprinkler system as if a sprinkler has opened. It is an alarm-initiating input, not a supervisory input. If you program waterflow as “supervisory only,” occupants and the fire department may never receive a fire alarm while the sprinkler is actually flowing. That is a sequence-of-operations error, not a sprinkler-fitter preference.
Vane versus pressure
Vane (paddle) switches sit in the pipe. Flow deflects a paddle and operates a switch after the retard. They are commonly used on wet-pipe systems and must be listed for the pipe size. A vane that is too small, installed against the flow arrow, or left with the paddle jammed against a fitting is how you get both false alarms and no alarms.
Pressure switches respond to a change in system pressure. They are the usual choice on dry-pipe, preaction, and deluge systems, where there is no water at the device until the system trips. They also appear on some wet systems, often on alarm-line / retard-chamber trim. Do not drop a vane into a dry pipe and hope: the paddle can sit in air, obstruct the valve, or corrode when the system finally trips.
Retard, surges, and still alarming on real flow
Fire-pump starts, municipal pressure spikes, and water hammer can twitch a vane for a few seconds without a sprinkler opening. Commonly taught NFPA 13 / NFPA 72 practice uses a retard so those surges do not become building fire alarms. Classroom numbers you will hear repeatedly are about 30 to 90 seconds. The retard may be a mechanical retard chamber on the alarm trim or an electronic delay in the switch or the control unit. The teaching point is the same: ignore short surges, still alarm on sustained flow.
Hold a second number next to that range. Commonly taught NFPA 72 practice is that waterflow still has to initiate an alarm within 90 seconds of flow equal to a single sprinkler at the device. A retard that swallows a weekly pump test is useful. A retard that also swallows a real one-head fire is not. Zero delay on a wet riser that sees pump tests is how shops earn false-alarm fines (and New York has false-alarm civil penalties under GBL §69-vvv for alarm-system work). A five-minute “so we can silence it” delay is not the surge window.
Waterflow still needs a test connection (inspector’s test) downstream of the switch. Acceptance and periodic testing belong in later service chapters; as an installer you still pipe and program as if someone will open that valve on purpose.
Supervisory devices
A supervisory signal reports that a supervised fire-protection feature is off-normal, not that a fire is burning. The control unit must present it as supervisory — typically a distinct designated supervisory indication — not as a general alarm and not as a mere wiring trouble. Restoral of the feature should restore the point.
Common supervisory points on sprinkler-related work:
| Condition | What the switch actually sees | Typical signal |
|---|---|---|
| Control-valve tamper | OS&Y, butterfly, or post-indicator valve not fully open | Supervisory |
| Low air on dry pipe or preaction | Supervisory air below the listed band | Supervisory |
| High air | Overpressure that can delay trip | Supervisory |
| Low temperature in a valve room | Freeze risk for wet trim or dry valves | Supervisory |
| Tank level or fire-pump status | Level, pump running, or pump power contacts | Supervisory unless the approved sequence says otherwise |
Tamper switches are the exam favorite. A sprinkler control valve that can be closed without a signal is an impaired system. The switch is set so leaving the fully open position is off-normal — not so that only a missing padlock creates a signal. After any valve work, restore the valve fully open and confirm the supervisory point restores. A wiring fault on the tamper circuit is still a trouble. Trouble is not a substitute for “valve closed.”
Keep three words separate on the closed-book exam: alarm (fire, manual, waterflow), supervisory (off-normal protection feature), and trouble (path, power, or device fault).
Duct smoke detectors
A duct smoke detector samples air moving in an HVAC duct. Its job is smoke control for the air handler: typically fan shutdown, damper control, or another emergency control function so the duct does not distribute smoke through the building. Chapter 15 returns to HVAC shutdown as a control-function topic. Here, treat the duct detector as an initiating device with listed hardware. Product listing is commonly discussed under UL 268A.
Listed sampling tubes must match duct width, hole pattern, and airflow direction in the installation sheet. An exhaust tube where the listing requires one, a proper housing gasket, and access for magnetic test or listed aerosol are part of the installation, not optional trim. A detector head stuffed through a random hole is not a listed duct detector.
Whether that input is alarm or supervisory is a sequence-of-operations decision. Many specifications use supervisory so a dirty or overly sensitive duct detector does not evacuate the building while the air handler still stops. Other occupancies and AHJs require an alarm. Teach both possibilities and read the approved matrix. A duct detector is not a substitute for area smoke detection in occupied rooms. HVAC shutdown and room detection are different jobs. Mechanical-code triggers (airflow thresholds that require duct detection) live in the adopted mechanical / building provisions; do not invent a unique New York cubic-feet-per-minute table for this exam.
Carbon monoxide as a fire-alarm input
Carbon monoxide detection is occupancy- and code-driven. New York does have dwelling carbon monoxide alarm requirements — residential rules that commonly show up as single-station or multiple-station alarms in dwelling units, with placement relative to sleeping areas. Those dwelling rules are not the same thing as a commercial fire-alarm initiating-device schedule, and this guide will not invent a statewide commercial CO grid.
On this exam, keep three distinctions:
- Single-station / multiple-station CO alarms (commonly UL 2034) that operate locally in a dwelling. They may never touch the fire-alarm control unit.
- System CO detectors (commonly UL 2075 detectors used with a control unit) where the adopted code or occupancy actually requires system detection and monitoring.
- Fire occupant notification (Temporal-3) versus CO notification, which is commonly taught as Temporal-4. Do not map a CO detector onto the building fire-evacuation pattern unless the approved sequence says so.
If the occupancy requires system CO, use listed detectors, the manufacturer’s instructions, and the adopted Uniform Code section that applies. A hardware-store plug-in alarm is not an automatic substitute for a system detector on a UL 864 control unit, just as a UL 217 smoke alarm is not a UL 268 system smoke detector.
Exam mix-ups to refuse
- Calling waterflow “supervisory” because a sprinkler contractor installed the switch.
- Treating a valve tamper as a fire alarm, or a wiring trouble as a closed valve.
- Mounting a pull station at strobe height (80–96 inches) or at a random switch height that misses the 42–48 inch operable-part teaching range.
- Using a duct detector as the only smoke detection for occupied rooms.
- Claiming every New York commercial building has a published statewide CO-device table that replaces occupancy chapters.
Scenario. A wet-system riser has a vane switch with the retard set near zero. The weekly fire-pump test sends a building-wide fire alarm. The fix is not “take waterflow off the panel.” The fix is a listed retard in the commonly taught surge window, a correct vane or pressure device, waterflow still reported as alarm, and a test connection that proves one-head flow still initiates that alarm.
A waterflow switch on a wet-pipe sprinkler riser is delayed so pump start and pressure surges do not create a fire alarm. Which delay range is commonly taught for that retard function, while real sprinkler-level flow still has to initiate an alarm?
Which field condition is commonly treated as a supervisory (off-normal) signal rather than a fire-alarm initiation?
A listed duct smoke detector is installed in an air-handling unit serving a New York occupancy. Which role does independent OpenExamPrep teaching emphasize for the installer exam?