Engine Fire Protection Systems Flashcards
What are the four types of engine fire detection systems?
Thermoswitch system, thermocouple system, thermistor-type continuous-loop system, pneumatic-type continuous-loop system.
Which type of fire detection system operates on the principle of the rate of temperature rise?
The thermocouple system.
Why must the reference junction in a thermocouple fire detection system be thermally insulated?
This is 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.
How do you check thermocouple fire detection system for operation?
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.
How is a pneumatic-type continuous-loop fire detection system checked for operation?
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.
