Fire Alarm Flashcards
What are the 4 elements to a fire?
- fuel
- heat
- oxygen
- chemical chain reaction to above items
In fire fighting terms what is “Starvation?”
The process of depriving the fire of fuel, like combustible materials.
In fire fighting terms what is “Cooling?”
The process of depriving the fire of heat. For example, by applying water to a fire, you absorb the heat and reduce the temperature needed to support combustion.
In fire fighting terms what is “Smothering?”
The process of depriving the fire of oxygen
In fire fighting terms what is “Interference?”
The process of applying extinguishing agents, such as dry chemical, to stop the chemical chain reaction
What does Class A fire extinguisher fight?
Paper, Wood, Cloth, Ordinary combustibles
What does Class B fire extinguisher fight?
Flammable liquids such a diesel and gas
What does Class C fire extinguisher fight?
Energized Electrical Equipment fires
What does Class D fire extinguisher fight?
Metals such as magnesium, potassium, titanium
What does Class K fire extinguisher fight?
Cooking fires with oil and fat
What is water in a fire extinguisher good for fighting. How does it work?
Class A fires. Cooling
What is Foam in a fire extinguisher good for fighting. How does it work?
It separates oxygen from the other elements in the fire triangle by smothering the fire.
What is Carbon Dioxide in a fire extinguisher good for fighting. How does it work?
It removes the oxygen element and some heat with a very cold discharge. Generally, it is
effective on Class B and C fires, but not Class A fires.
What is Dry Powder in a fire extinguisher good for fighting. How does it work?
Interrupts the chemical chain reaction of the fire. The multipurpose dry chemical is the most widely used type of fire extinguisher and is effective on Class A, B, and C fires.
What is Wet Chemical in a fire extinguisher good for fighting. How does it work?
is a new agent that extinguishes the fire by removing the heat element and prevents re-ignition by creating a barrier between the oxygen and fuel elements. This type of extinguisher was developed for modern, high efficiency deep fat fryers in commercial cooking operations. Some may also be used on Class A fires in commercial kitchens.
The rating on the combination extinguisher is rated 4-A:80-B:C. What does this code mean?
The “A” rating is a water equivalency rating. Each “A” is equal to 1.25 gallons (4.73L)
of water. So 4A = 5 gallons (18.92L) of
water.
The “B:C” rating is equivalent to the amount of square footage that the extinguisher can
cover, handled by a professional. This extinguisher can cover 80 ft
The “C” rating never has a numeric value as it simply indicates that the chemicals inside
are non
-conductive
-suitable for use on energized electrical equipment
What does PASS method mean?
When using a fire extinguisher:
- Pull
- Aim
- Squeeze
- Sweep
What are the four stages to a fire?
- Incipient Stage
- Soldering (smoke) Stage
- Flame Stage
- Heat Stage
What is an IDC?
Initiating Device Circuit. Used to notify fire alarm panel that a fire sensing device (IE smoke detector) has triggered.
What is SDC?
Signalling Device Circuit. Alarm panel uses these to turn on bells and strobes etc.
What is FACU?
Fire Alarm Control Unit. The brains of the fire alarm system.
What are rules for Primary Power to Fire Alarm Control Unit (FACU?)
A fused circuit of 115V, 60 Hz located on the load side of the service and taken from as close to the incoming mains (meter) as is possible. A red painted fused disconnect or breaker labelled FIRE ALARM, able to be locked in the on-position, is required. [See CEC Rule 32-108 (1), (3)]
What are rules for Standby Power to Fire Alarm Control Unit (FACU?)
upon a loss of primary power lasting more than 15 seconds, the power source must be transferred to standby power. The FA system will immediately and automatically transfer back to the main power source upon its restoration. Standby power may be an emergency circuit from a generator or, more often, a battery bank found in the FA control unit itself. The standby power must be sized to provide supervisory (normal non-alarm) power for 24 hours, followed by full-load (alarm)
power for 5 minutes.
Where must the Annunciator Panel be located?
Building Front Entrance
What is an Ancillary Device?
Ancillary devices are building devices or components that are not part of the FA system but are controlled by it because they serve a life-saving function.
What is an Ancillary Device, Door Holder Release do?
Allows doors to close upon a fire alarm.
What is an Ancillary Device, Maglock Release do?
Allows maglocked doors to unlock and become open during a fire alarm.
What is an Ancillary Device, Elevator Recall or Capture do?
Sends elevators to ground floor and remain open for firefighters’ use.
What is an Ancillary Device, Damper Control do?
Damper Control
The FA system will close dampers to prevent fresh air from entering and feeding the fire,
and open other dampers to allow smoke to ventilate outside.
What is an Ancillary Device, Fan Controls do?
To control the spread of deadly smoke, the FA system will turn off fresh air fans and turn on exhaust fans. To stop smoke from entering stairwells, fans provide
fresh air and positive pressure to these areas during a fire alarm.
What does Auxiliary circuit do?
This term pertains to the automatic connection of the FA system in a building to a remote
monitoring service or directly to the fire department for certain public building
installations, such
as hotels, shopping centres, schools and hospitals. An auxiliary relay contact or a city
-tie module
(CTM) is included in the FACU for this purpose. Upon activation of any alarm on the system,
this relay will activate and send a signal to the monitoring service/fire department.
What is simplex communication?
The communication is like broadcast radio. It only goes in one direction.
What is Half-Duplex communication?
The communication can goes either direction. But only one direction at once. Like using a walkie-talkie.
What is Full-Duplex Communication?
The communication can go both ways at the same time. Just like a phone call.
How many strokes per minute for an Alert-Signal?
20
How many strokes per minute for an Alarm-Signal?
120
What is a single stage system?
An activated initiating device will sound a general alarm on all signal devices, warning all occupants to vacate the area immediately. These systems are
most common where people are able-
bodied and familiar with the exits, such as schools,
apartment building and industrial plants.
What is a Two stage system?
An alert signal will sound upon the operation of any initiating device, which serves to advise supervisory staff of a possible fire condition. This first-stage (alert stage) is limited to a maximum of 5 minutes before a general alarm sounds, allowing staff to investigate the source of the activation.
What is coded fire alarm?
When fire alarm sounds, within the first minute, tone patterns may indicate which zone has tripped. It can repeat four times. After which time general alarm signals.
What does Indicating mean for a fire alarm?
At the annunciator panel in the lobby it will indicate which zone or IDC was tripped. Causing the alarm.
Fire alarm zones, What is an Alarm Initiating zone?
Alarm initiating zones are circuits wired to field devices such as smoke or heat detectors, pull stations or sprinkler flow switches. Activation of these IDC zones will cause the audible signals to sound in accordance with the specific system operation stylelarm initiating zones are circuits wired to field devices such as smoke or heat detectors, pull stations or sprinkler flow switches. Activation of these IDC zones will cause the
audible signals to sound in accordance with the specific system operation style.
Fire alarm zones, What is a Supervisor Initiating zone?
Supervisory initiating zones are circuits wired to devices such as sprinkler valves, supervisory switches or sprinkler low-pressure sensors. Activation of these zone types will not cause the general alarm to sound, but will activate a supervisory condition in the
system.
Fire alarm zones, What is a Monitor Initiating zone?
Monitor initiating zones simply monitor the status of
devices such as fire dampers (open
or closed) or the condition of fans (on or off). Monitor zones do not activate SDC’s or issue system trouble signals, only annunciating their status via visual indicators.
What are benefits of having fire alarm zones?
What benefit is there in having zones within a
building? The concept of zones provides a number
of advantages and fire safety benefits, which is why they are required by Building Code.
Zones provide a logical breakdown by building area, making it easier and faster for
supervisory/maintenance personnel
to locate troubles or alarm signals.
Firefighting personnel can respond rapidly when the trouble area’s zone is known.
Zoning also provides a means to monitor the spread of fire, as smoke and flame may
progress from zone to zone
What things are defined as a fire alarm zone?
Each floor of up to 2000 m
Stairwells, garbage chutes and elevator shafts all require separate zones. Since these
shafts generally cut through several floors of a building and a fire could involve the entire
shaft, they cannot be connected to a specific floor’s zone.
Any room or area with a 2-hour fire resistant separation requires a separate zone.
What is the supervisory current value in a fire alarm IDC circuit?
40ma
In a fire alarm system are IDC devices NO or NC?
NO
What voltage does a FACU IDC circuit run at?
24VDC