Unformatted text preview: wo relays slave and sensitive and thermal test unit. Relays control warning lights. Thermo couples control relays. Thermo couples and sensitive relays are connected in series. Active thermo couples are placed in locations where fire is likely to occur and one thermo couple is placed in location that is relatively well protected from the initial flame. The temperature of reference thermo couple will eventually reach that of other thermo coir /s there will be no tire warning if everything heats up uniformly as it does in normal operation. When fire occurs the temperature in the area of active thermo couple will exceed temp of reference thermo couple causing a current to flow through sensitive relay any time. The current is greater than 4 milli Amps (0.004 Amps). The sensitive relay operates closes the contact thus energizing the slave relay which closes the contact thus brings fire warning light and alarm on. Total number of thermo couples in individual detector circuits depends on the size of fire zone and total...
View Full Document
This note was uploaded on 03/09/2011 for the course AIRCRAFT 2008.09.00 taught by Professor Dr.alan during the One '11 term at TAFE NSW - Sydney Institute.
- One '11