Fire protection systems Flashcards
(20 cards)
briefly describe the components of a thermal switch fire detection system
temperature sensitive switches that complete a circuit at a specific temperature and trigger a warning
Are thermal switches wired in series or in parallel with each other?
Parallel
How are the detector units in a double-loop Fenwal system wired?
in parallel between two complete loops of wiring
In what way is a thermocouple fire warning system different from a thermal switch system?
Thermocouple systems are sensitive to the rate of temperature change, whereas thermal switch system respond to a specific temperature value.
Briefly describe the components of a KIDDE continuous loop fire detection system
A KIDDE system has an iconel loop whose resistance changes with temperature
briefly describe the components and operation of a Lindberg fire detection system
A stainless steel tube contains an inert gas and a discrete material that absorbs some of the gas. When the tube heats up, some gas is released, raising the pressure in the tube, which activates a pressure switch.
describe the process or mechanism by which a photoelectric smoke detector generates a warning of a possible fire.
Smoke particles refract light in the detector unit causing the photelectric cell to conduct electricity and trigger the alarm.
How can the operation of photelectric smoke detector be tested?
by actuating a test switch
Name two types of smoke detection system used in aircraft
Light refraction (photoelectric) types and ionization types
What are the usual locations where a carbon monoxide detector would be installed?
in an aircraft cockpit or cabin
How does a carbon monoxide detector indicate the presence of this deadly gas?
The tan spot on the detector turns gray or black
What are the possible effects of kinks and sharp bends in the sensing element(s) of a fire warning system?
False fire warnings caused by short circuits
How is a Freon container checked for proper pressure?
A chart must be used to determine the maximum and minimum gauge pressure readings based on the ambient temperature.
Name the two basic types of fire extinguishing systems
Conventional system
High-rate discharge system
Name the extinguishing agent most commonly used by conventional fire extinguishing systems
CO2
Name the extinguishing agent most commonly used by high-rate discharge fire extinguishing system
Halon,
How are freon bottles protected from excessively high temperature and how can you tell that this has occurred
A thermal fuse (blowout disk) will release the agent if the bottle temperature exceeds a certain limit. This blows out a red indicator disk
What condition is indicated if the yellow disk is missing in a fire extinguishing system?
Discharged normally
Describe the mechanism by which a freon bottle is discharged
An electrical signal fires an explosive squib, which ruptures a frangible disk
How is the service life of a discharge cartridges calculated?
From the date stamped on the cartridge by the manufacturer.
