Basic Features of a Fire Alarm System Flashcards
The primary function of a FA system is to protect ________
People
Name three basic elements of any FA system
- Initiating devices
- Signal devices
- Control unit
Most FA automatic initiating devices respond to ________ and ________.
smoke, heat
The most common FA signal devices are __________ and _________
bells, speakers
The heart of the FA system is the __________
control panel
In the single-stage FA system, what happens when an initiating device operates?
All signal devices go into alarm
In a two-stage FA system, what usually happens when a manual pull-station is operated?
Signal devices initially go to an alert condition. This may be followed by an alarm condition.
A typical zone in a building might be a ________ or _______
floor, wing
Name one advantage of having many zones in a building
Makes it easier to track down the location of the trouble spot
What special feature must all manual pull-stations in a two stage FA system incorporate?
Key-operated switch
Name the three most common initiating devices
- Manual pull-stations
- Heat detectors
- Smoke detectors
Where would it not be practical to use a rate-of-rise heat detector?
In a commercial kitchen
Are all thermal detectors restorable types?
No
Which type of automatic fire detector usually gives the earliest warning of a fire condition?
Ionization smoke detector
What is the reason for using smoke detectors in air-handling duct systems?
To shut down fans and dampers that might worsen the fire situation
What are the two most common types of smoke detectors?
Ionization type and photoelectric type
Which type of smoke detector would be most suitable in an area of high ambient humidity?
Photoelectric type
What is the function of a key-operated manual pull station?
To enable the operator to change an alert signal to an alarm signal
Is a rate-of-anticipation detector restorable? What advantage does it have over a standard fixed-temperature thermal detector?
Yes. It responds faster to ambient air temperature rise.
Identify three locations where manual pull-stations are normally required
- Entrances to stairways
- Exits
- Large assembly rooms
Are single-stroke bells (and chimes) usually used for alert signals or alarm signals?
Alert signals
The common voltage used in FA wiring is ______
24V DC
In a typical control panel, what do the green, amber and red lights signify?
- Green is for AC power supply
- Amber is for trouble condition
- Red is for alarm condition
What is the reason for “supervising” FA systems?
To monitor the wiring to ensure no open or ground conditions are present that would inhibit the operation of the devices should a fire situation arise
How is electrical supervision of wiring accomplished in an FA system?
By maintaining a continuous current in the wiring. Any interruption brings up a trouble signal.
The standby battery used in FA systems must have enough capacity to supply the supervisory current for a minimum of how long?
24 hours
Which class of FA wiring uses the end-of-line resistor?
Class B
Name one advantage and one disadvantage of the Class A system
An open in the wiring system does not knock out any of the initiating or signal devices, but installation costs are higher because of this additional wiring
Which two features of the addressable FA system make it advantageous over the non-addressable system for certain installations?
Activated devices are easily identifiable and the wiring costs are often less
If an opening occurs in a Class B wiring system because a wire comes off the terminal of the end-of-line resistor, all devices on that zone are de-activated. True or False?
False
Where must an annunciator be located in a building?
At the main door entrance to the building at street level
What type of FA systems require annunciator panels?
FA installations that have more than one zone
What features would you expect to find in a typical FA annunciator panel?
A map of the building and zone alarm indicating lights, plus a trouble light and an audible signal device
What are the mounting heigh requirements for manual pull-stations?
1.35m to 1.5m to centre AFF
What are the mounting height requirements for alarm bells?
Not less than 1.8m to centre AFF
What are the mounting height requirements for the control panel?
Not more than 2.4m to top AFF
What are the mounting height requirements for end-of-line resistors?
Not more than 1.8m AFF
Where are smoke and heat detectors normally mounted?
On the ceiling
Conductors used in FA systems must be of what material?
Copper
What is the minimum size of conductor permitted in FA wiring?
22 AWG
What does the CEC rule say about stranded wires in FA systems?
Stranded conductors with more than seven strands must be bunch-tinned, or terminated in compression connectors
Is it permitted to put non-FA equipment on the FA circuit?
No
How must the circuit breaker for the FA circuit be identified?
Clearly and conspicuously, and it must be red
What are the code requirements for the FA circuit breaker location?
It must be located as close as possible to the incoming power supply.
Why is it not advisable to use a beggar to test FA systems?
Electronic components could be damaged by excessive megger voltage
An ohmmeter used used to test FA wiring for what type of faults?
Opens, shorts, and grounds
If an initiating circuit is a Class B type having four heat detectors and a manual pull-station, what reading should you expect on an ohmmeter connected to the two wires that will connect to the control panel?
end-of-line resistor value (approximately)
What would be the reason for connecting an end-of-line resistor to the output wiring terminals in place of the signal or initiating wires when making an ohmmeter test?
To check if the problem is in the control panel
True or False. Some, but not all, manual pull-stations are required to be tested in an FA system
False
True or False. When testing the FA system, only the restorable heat detectors are tested and no testing is done on non-restorable types
False
What agency publishes the standards for testing FA systems?
The ULC (Underwriters Laboratories of Canada)
What are the five regulatory groups that have input regarding FA systems?
- NBC (National Building Code)
- ULC (Underwriters Laboratories of Canada)
- CSA (Canadian Standards Association)
- CEC (Canadian Electrical Code)
- NFC (National Fire Code)
- Provincial and municipal fire authorities
What is a Type 1 fire alarm system?
General alarm system in which any alarm-initiating device activates all alarms in the system. Defined as a single-stage, non-coded, non-indicating, local, general alarm system. Not permitted in buildings that are required to have an annunciator
What is a Type 2 fire alarm system
General alarm system equipped with annunciator to indicate the zone in which an alarm was initiated. Defined as a single-stage, zoned, non-coded, indicating, local, general alarm system
What is a Type 3 fire alarm system?
Operation of any alarm-initiating device first causes a coded signal to sound on all audible alarm devices. Coded signal repeats at least four times after which a general fire alarm is automatically sounded. Also equipped with annunciator. Defined as a single-stage, zone-coded, indicating, local, general alarm system
What is a Type 4 fire alarm system?
Operating of any alarm-initiating device causes a distinctive alert alarm. Uses a manual key-operated alarm stations that allow authorized people to activate all alarm devices in the zones to be evacuated. Equipped with annunciator and backed up with a general fire alarm. Defined as a two-stage, zone-coded, indicating, local, fire alarm system
What is a Type 5 fire alarm system?
Similar to Type 4 system except that the operation of any alarm-initiating device causes a coded signal to sound the alert alarm devices, indicating the zone in which the alarm was initiated. Defined as a two-stage, zone-coded, indicating, local, fire alarm system
How many zones are required in institutional buildings such as nursing homes?
Minimum two zones per floor
A building with an area of ______ or less, and a maximum of _____ storeys may be all on one zone
2000m(squared), three
A manual pull-station is a mechanical switch that is __________
normally open
Some fixed temperature devices are rated to activate at ____°F (approx. ______°C) and others at ____°F (approx. ___°C)
135°F (57°C), 190°F (88°C)
