Fire Alarm Systems Flashcards

Questions and Answers

What is a smoke alarm?

A device that detects carbon monoxide

A device that triggers sprinklers for fire suppression

A heat sensor installed in ceilings

A standalone device with a built-in audible sounder and control component (correct)

What is fire alarm circuit design dependent on?

non addressable (conventional) or addressable, Class A or B, single stage or 2 stage

What is a field device?

A remote device that is electrically connected to a control unit.

What is an initiating field device?

It provides information regarding change from normal to fire condition. Signup and view all the answers

What is a signalling field device?

They respond and warn occupants of fire condition. Signup and view all the answers

What is a supervisory field device?

They monitor a sprinkler system to determine if it is fully operational. Signup and view all the answers

What are the two categories field devices can be separated into?

non addressable (conventional) and addressable Signup and view all the answers

What is a non-addressable field device?

The control unit cannot identify individual field devices, only which complete circuit or zone. Signup and view all the answers

What is a Class B circuit configuration?

A Class B has field devices connected in parallel and an end of line device. Signup and view all the answers

How is electrical supervision provided in a Class B circuit?

By a current in the mA range that flows continually through the wiring of the circuit. Signup and view all the answers

What are the three current conditions that can arise in a Class B circuit?

high current, short circuit, and no current Signup and view all the answers

What causes a high current flow in a detection circuit in a Class B circuit?

Activation of an initiating device, short circuit between conductors, or alarm condition. Signup and view all the answers

A short circuit across the circuit conductors in a signal circuit causes a ____ condition for that circuit at the control panel.

trouble condition Signup and view all the answers

What would cause no current flow in either an initiating or notification circuit conductors? This results in a ___ condition at the control panel.

trouble condition Signup and view all the answers

When an open circuit occurs in a Class B circuit what happens to the devices beyond the break?

They are inoperable and not able to initiate an alarm condition. Signup and view all the answers

What does IDC and NAC mean?

IDC- initiating device circuit, NAC- notification appliance circuit Signup and view all the answers

What happens in the IDC or NAC if there are ground faults?

They cause a trouble condition and ground fault indication at the control panel. Signup and view all the answers

What is a Class A circuit?

The field devices are also connected in parallel but no EOL device. Signup and view all the answers

What is the main advantage to a Class A over a Class B circuit?

In a Class A, if an open circuit occurs, the field devices beyond that open still operate and can still initiate an alarm condition. Signup and view all the answers

What happens during an alarm condition in a Class A circuit?

The polarities of the NACs are reversed, causing the signaling devices to operate. Signup and view all the answers

What is a Tamper device?

Devices that detect the removal or opening of a protective cover. Signup and view all the answers

What are supervisory devices in sprinkler systems?

They determine if the sprinkler is fully operational. Signup and view all the answers

If a tamper switch is opened what happens?

A trouble signal on the circuit but does NOT prevent any initiating or supervisory devices from reporting an alarm indication. Signup and view all the answers

Match the following forms of devices with their descriptions:

Initiating field device = Provides information regarding the change from normal to fire condition Signaling field device = Warns occupants of fire condition Supervisory field device = Monitors the system's operational status Signup and view all the answers

What are addressable devices?

Devices that can be identified and operated independently of the other devices by the control panel. Signup and view all the answers

What happens during a fire condition with addressable devices?

The addressable initiating device informs the control panel which device and where the fire is located. Signup and view all the answers

What is a distributed type control?

Two or more connected control units, only one unit contains the CPU. Signup and view all the answers

How does a DCL indicate a trouble condition?

If the control panel doesn't get a response from the active field device, it interprets this as a trouble condition. Signup and view all the answers

What does DCL stand for?

Data communication line Signup and view all the answers

What are the two types of DCL circuits?

DCLA - 4 conductor, DCLB - 2 conductor Signup and view all the answers

What do monitor modules do?

Used for N.O contacts non-addressable initiating devices or supervisory devices. Signup and view all the answers

What are signal modules, and what do they do?

Used for non-addressable notification devices and provides electrical supervision required by non-addressable devices. Signup and view all the answers

What are control modules, and what do they do?

Used to provide automatic control of ancillary devices within the building. Signup and view all the answers

What is a notification appliance circuit extender panel?

Used to prevent voltage drop and power supply problems in large systems. Signup and view all the answers

How does the NAC communicate with the main fire alarm control panel?

Uses DCL to report conditions and receive instructions for operation. Signup and view all the answers

What are auxiliary systems?

Central alarm control facilities that include security, communication, heat, and ventilation. Signup and view all the answers

What are transponders?

Interface devices that transmit information to and from field devices on several IDCs and NACs. Signup and view all the answers

What is a DCLC circuit?

DCLA that goes through more than one required building code fire zone. Signup and view all the answers

What are fault isolation modules required for?

In DCLC circuits, to isolate zones if a short circuit occurs. Signup and view all the answers

When are single isolation modules required?

Between zones on the same floor. Signup and view all the answers

When are two isolation modules required?

Between zones when on different floors or separated by fire separation. Signup and view all the answers

What is the recommendation for single-stage Class A?

Primary and alternate loop shall not be run in the same raceway. Signup and view all the answers

Study Notes

Smoke Alarms

Standalone device featuring a built-in audible sounder, control component, and sensor.

Fire Alarm Circuit Design

Depends on type: non-addressable (conventional) vs. addressable.
Configurations include Class A or B, and single-stage or two-stage systems.

Field Devices

Remote devices connected to a control unit, categorized into initiating and signaling devices.
Initiating devices signal a transition from normal to fire conditions.
Signaling devices alert occupants of fire conditions.

Circuit Configuration

Non-addressable devices cannot be individually identified by the control unit; can be connected in Class A or B configurations.
Class B circuits connect devices in parallel with an end-of-line (EOL) device for current monitoring.

Class B Circuits

Supervision is provided through a constant current in the milliamp range.
High current, short circuit, or no current conditions can arise, affecting circuit integrity.
Short circuits trigger a trouble condition at the control panel.

Class A Circuits

Devices are connected in parallel without an EOL device, using an alternate loop back to the control panel.
Provides electrical supervision from both ends of the loop, allowing detection of fire conditions from either direction.
Advantage: Open circuits still allow devices beyond to operate, resulting in alarm initiation.

Supervisory and Tamper Devices

Supervisory devices monitor systems like sprinklers to ensure operational status without detecting fire.
Tamper devices indicate unauthorized removal/opening of protective covers, triggering a trouble signal without interfering with alarm reporting.

Addressable Devices

Identified individually by the control panel with unique addresses, allowing for precise location identification during fire events.
Operate via Data Communication Links (DCL) which provide electrical supervision for active addressable devices.

Notification Appliance Circuits

Extend far from the control panel to avoid voltage drop issues; separated power supplies support device operation and supervision during alarms.

Auxiliary Systems

Central alarm facilities may include security, communication, heating, and ventilation systems alongside fire detection and alarms.

Isolation Modules

Required in complex circuit configurations for fault isolation, especially in Distributed Type Control systems to maintain circuit function during faults.

Wiring Installation Standards

Must comply with CEC section 32 and ULC-S524, ensuring safety and effectiveness in fire alarm systems.

Current Conditions Overview

Class A and B circuits can experience high current, short circuits, or no current conditions affecting device operation.
Open circuits in Class B render devices beyond the break inoperable, while Class A devices remain operational.

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Description

Test your knowledge on wiring procedures and components of fire alarm systems with these flashcards. Each card provides definitions and key concepts essential for understanding smoke alarms and circuit design. Perfect for students and professionals in fire safety training.