Fire Protection Systems

Question 1

Briefly describe the components of a thermal switch fire detection system.

Answer 1

Temperature sensitive switches that complete a circuit at a specific temperature and trigger a warning.

Question 2

Are thermal switches wired in series or in parallel with each other?

Answer 2

Parallel.

Question 3

How are the detector units in a Double Loop Fenwall system wired?

Answer 3

In parallel between two complete loops of wiring.

Question 4

In what way is a thermocouple fire warning system different from a thermal switch system?

Answer 4

Thermocouple systems are sensitive to the rate of temperature change.
Thermal switch systems respond to a specific temperature value.

Question 5

Briefly describe the components of a Kidde continuous loop fire detection system:

Answer 5

Kidde system has Inconel loop whose resistance changes with temperature.

Question 6

Briefly describe the components and operation of a Lindburg fire detection system.

Answer 6

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 the pressure switch.

Question 7

Describe the process or mechanism by which a photo electric smoke detector generates a warning of a possible fire.

Answer 7

Smoke particles refract light in the detector unit causing the photoelectric cell to conduct electricity and trigger the alarm.

Question 8

How can the operation of a photo electric smoke detector be tested?

Answer 8

By actuating a test switch.

Question 9

Name two types of smoke detection systems used in aircraft:

Answer 9

Light refraction (photoelectric).
Ionization type.

Question 10

What are the usual locations where a carbon monoxide detector would be installed?

Answer 10

Cockpit.
Cabin.

Question 11

How does a carbon monoxide detector indicate the presence of this deadly gas?

Answer 11

The tan spot on the detector turns gray or black.

Question 12

What are the possible effects of kinks and sharp bends in the sensing elements of a fire warning system?

Answer 12

False fire warnings caused by short circuits.

Question 13

How is a Freon container checked for proper pressure?

Answer 13

A chart must be used to determine the maximum and minimum gauge pressure readings based on the ambient temperature.

Question 14

Name the two basic types of fire extinguishing systems:

Answer 14

The conventional system.
The high rate discharge system.

Question 15

Name the extinguishing agent most commonly used by conventional fire extinguishing systems.

Answer 15

Carbon dioxide (CO2)

Question 16

Name the extinguishing agent most commonly used by high rate discharge fire extinguishing systems.

Answer 16

Halon (a.k.a. Freon)

Question 17

How are Freon bottles protected from excessively high temperatures and how can you tell that this has occurred?

Answer 17

A thermal fuse (blow out disc) will release the agent if the bottle temperature exceeds a certain limit. This blows out a red indicator disc.

Question 18

What condition is indicated if the yellow disc is missing in a fire extinguishing system?

Answer 18

A normal discharge.

Question 19

Describe the mechanism by which a Freon bottle is discharged.

Answer 19

An electrical signal fires an explosive squib, which ruptures a frangible disc.

Question 20

How is the service life of a discharge cartridge calculated?

Answer 20

From the date stamped on the cartridge by the manufacturer.