S95 Initiating Devices 4

Question 1

A sprinkler system waterflow switch is classified as what type of initiating device?

Accepted Answer

Alarm initiating device

Answer

Waterflow switches are alarm initiating devices because water flowing through a sprinkler pipe indicates a fire has activated a sprinkler head, requiring an alarm signal.

Question 2

A waterflow switch on a wet-pipe sprinkler system typically has a built-in retard feature. What is the purpose of this retard?

Accepted Answer

To prevent false alarms caused by momentary pressure surges or water hammer

Answer

The retard chamber delays the alarm signal for 30–90 seconds to filter out brief pressure surges in the piping that would otherwise cause nuisance alarms.

Question 3

A valve supervisory switch (tamper switch) on a control valve generates what type of signal at the fire alarm control panel?

Accepted Answer

Supervisory signal

Answer

A valve supervisory switch monitors the open or closed position of a sprinkler control valve and generates a supervisory signal when the valve is moved from its normal (fully open) position.

Question 4

Which initiating device is specifically designed to detect the presence of flame rather than smoke or heat?

Accepted Answer

Infrared or ultraviolet flame detector

Answer

Infrared (IR) and ultraviolet (UV) flame detectors sense the specific radiation wavelengths emitted by flames, providing very fast response to open fires.

Question 5

A duct smoke detector must be located how far downstream from air supply inlets or outlets, mixing dampers, or any obstructions per NFPA 72?

Accepted Answer

At least 3 duct widths

Answer

NFPA 72 requires duct smoke detectors to be installed at least 3 duct widths downstream from any obstruction or air inlet/outlet to ensure representative air sampling.

(S95) Supervision of Fire Alarm System Practice Test

(S95) Supervision of Fire Alarm System Practice Test

S95 Initiating Devices 4