Supervisory and Trouble Signals Flashcards

A supervisory signal is received at the fire alarm control panel indicating a valve has moved from its normal position. What is the FIRST action required?

Answer: Investigate and restore the valve to its normal position

Supervisory signals indicate off-normal conditions that must be investigated and corrected by restoring the device to its normal supervised position.

Which of the following conditions would generate a TROUBLE signal rather than a supervisory signal?

Answer: A ground fault on a signaling line circuit

A ground fault on a signaling line circuit indicates a wiring or circuit integrity problem, which is classified as a trouble condition.

According to NFPA 72, how often must supervisory signals be tested in a system with central station monitoring?

Answer: Annually

NFPA 72 requires supervisory signal devices to be tested annually unless the authority having jurisdiction specifies a different frequency.

A building fire alarm system displays a trouble signal with an 'open circuit' fault on initiating device circuit 3. What does this indicate?

Answer: A wire break or disconnection exists on circuit 3

An open circuit trouble indicates a wire break, loose connection, or disconnected device that has interrupted the circuit continuity.

Which signal type is generated when a sprinkler control valve is closed more than 20% from the fully open position?

Answer: Supervisory signal

A tamper switch on a sprinkler control valve generates a supervisory signal when the valve moves significantly from its fully open (normal) position.

A sprinkler system water flow switch activates but no sprinkler heads have operated. The MOST likely cause is:

Answer: Pressure surge or water hammer in the system

Pressure surges or water hammer can momentarily activate a flow switch without actual water flow, often called a false alarm.

When a trouble signal is received at a protected premises FACP, NFPA 72 requires the trouble signal to be:

Answer: Acknowledged and investigated within 24 hours

NFPA 72 requires trouble signals to be acknowledged and the cause investigated and corrected within 24 hours of receipt.

What color is typically used to indicate a TROUBLE signal on a fire alarm control panel?

Answer: Yellow or amber

Yellow or amber indicators are the industry-standard color for trouble signals on fire alarm control panels, distinguishing them from red alarm signals.

A fire pump running signal at the FACP indicates:

Answer: The fire pump has started and may indicate a demand for water

A fire pump running signal is a supervisory signal indicating the fire pump has started, which may indicate actual firefighting water demand or an automatic test cycle.

Which device monitors the water level in a fire protection storage tank and generates a supervisory signal when the level drops below normal?

Answer: Low water level switch

A low water level switch monitors storage tank water levels and sends a supervisory signal when water drops below the minimum required level.

According to NFPA 72, a trouble signal audible notification device at the FACP must produce a sound that is:

Answer: A distinctive sound clearly different from alarm signals

Trouble signal notification must be distinctly different from alarm signals so personnel can immediately differentiate between emergency and maintenance conditions.

A cross-zoned detection system requires two separate detection zones to activate before sounding a full alarm. If only one zone activates, the FACP would typically display a:

Answer: Pre-alarm or investigation signal

In a cross-zoned system, single-zone activation typically generates a pre-alarm or investigation condition rather than a full alarm until the second zone confirms.

Which of the following is classified as a supervisory signal according to NFPA 72?

Answer: A post-indicator valve moved to a partially closed position

A post-indicator valve moved from its fully open position generates a supervisory signal because it represents an off-normal condition in the suppression system.

The purpose of a 'waterflow retard' on a wet-pipe sprinkler system alarm check valve is to:

Answer: Delay the alarm signal to reduce false activations from surges

A retard chamber delays the waterflow alarm signal by a few seconds to allow brief pressure surges to pass without triggering a false alarm.

In a fire alarm system, a 'loss of AC power' condition at the FACP is categorized as which type of signal?

Answer: Trouble

Loss of AC primary power is classified as a trouble signal because it indicates the system is operating on backup power and the primary power source is compromised.

A tamper switch on a fire suppression system valve is designed to generate a signal when the valve is moved from its normal position by as little as:

Answer: One or two turns of the hand wheel

Tamper switches are designed to activate after just one or two turns of the handwheel so that even slight valve movement is detected and reported.

Which of the following BEST describes the difference between a 'Class A' and 'Class B' signaling line circuit in terms of trouble signal capability?

Answer: Class A provides a trouble signal AND maintains communication past a single open fault; Class B loses communication past the fault

Class A circuits loop back to the panel so a single open wire fault still allows the panel to communicate with devices on the intact portion, whereas Class B loses all devices beyond the break.

A fire alarm system at a hospital shows a supervisory signal from the kitchen hood suppression system. The MOST likely cause is:

Answer: A control valve on the kitchen suppression system is not in its normal position

Supervisory signals from a suppression system most commonly indicate that a control valve or other supervised device has moved from its normal operating position.

When a monitoring company receives a supervisory signal from a protected premises, the FIRST action required by NFPA 72 is to:

Answer: Attempt to contact a designated representative at the protected premises

NFPA 72 requires monitoring companies receiving supervisory signals to promptly attempt to contact a designated representative at the protected premises to investigate the condition.

A carbon dioxide fire suppression system uses pressure switches to monitor the CO2 cylinder bank. A low-pressure reading from this switch would generate what type of signal?

Answer: Supervisory

Low pressure in a CO2 storage cylinder bank indicates the system may have insufficient agent to suppress a fire and is classified as a supervisory condition requiring investigation.