15.13 start and ignition Flashcards
what are the methods of start for an engine?
electric power
gas
hydraulic pressure
what is possible for maintenance purposes?
motor the engine over without ignition ‘dry run’
what will happen to exhaust gas temps during start up?
slight overshoot
what occurs first ignition or fuel injection?
ignition
how is the compressor and fan started?
starter motor
what disengages the starter motor?
a spring clutch operating centrifugally (sprug)
what is the principle of cartridge starting?
an impulse type turbine that is driven by high velocity gases from a burning cartridge
what air is required for an air starter?
30-50lbs per square inch
what is important about starter motor oil?
it has a sight plug
and a magnetic drain plug
how can the starter motor be disengaged manually?
manual override
what are the two types of electric starter?
direct cranking electrical system
starter generator system
what are the characteristics of the direct cranking electric motor?
-DC electric motor
-coupled with an electric gearbox & ratchet/ clutch
-used on small engines/ Apu’s
how does a starter generator system differ?
-it becomes generator through a secondary set of windings
-it does not disengage
-economically advantageous
how long is ignition activated?
only for a short period
when can continuous ignition be used?
when there is a risk of flame out
what is important when continuous ignition is occuring?
cooling
what are the two types of ignition systems?
capacitor
electronic
what powers the ignition system?
115AC
permanent magnetic generator
what does a typical ignition system have?
two exciters
two transponders
two intermediate ignition leads
how is flashover limited?
it is hermetically sealed
where is the energy sealed in a capacitor discharge exciter box?
in the capacitor
what is another name for an annular gap igniter?
a long reach igniter
how does a constrained gap plug differ?
it does not protrude into the liner
