Engine Fire Protection Systems

Question 1

What are four types of engine fire detection systems?

Answer 1

-Thermoswitch system
-Thermocouple system
-Thermistor type continuous
loop system
-Pneumatic type continuous
loop system (NEW_MATIC)

Question 2

Which type of fire detection system operates on the principle of the “rate of temperature rise”?

Answer 2

The thermocouple system

Question 3

Why must the reference junction in a thermocouple fire detection system be thermally insulated?

Answer 3

This is a rate of temperature rise system.

The reference junction must be insulated so its temperature will not rise as quickly as that of the measuring junctions if a fire should occur.

Question 4

How do you check a thermocouple fire detection system for operation?

Answer 4

Press the test switch.

This heats the test thermocouple enough for it to close the sensitive relay which in turn closes the slave relay and activates the fire warning light and bell.

Question 5

What would likely cause a false fire alarm in a thermistor type continuous loop system? am.ii.e.k3

Answer 5

Physical damage to the loop wire, like a nick, loose connection, which can lead to a fire.

Question 6

How is a pneumatic type continuous loop fire detection system checked for operation?

Answer 6

When the test switch is closed, low voltage AC flows through the tube that encloses the sensitive element.

This current heats the element enough for it to release sufficient gas to activate the alarm switch.