Starting System Flashcards
4 basic components of starting system
Stater motor
Ignition circuit
Fuel/air Supply
Control system
Self sustaining speed
Lowest RPM thr turbine will accelerate the engine without assistance from the starter
Types of starter
Electric
Gas turbine
Air or hydraulic
What is the Electric stater motor used for
Initial turning of the engine
Turns compressor
Once hit self- sustaining speed it drives the starter motor as a generator
Adv starter motor
Less weight
Low cost
No disengagement mechanism
Starter motor restricted operating time is?
20 secs
Between each 20 secs how long should you leave it to cool for
Normally 1 minuate
After 3 attempts the starter motor should be left to cool for how long
15 mins
For ignition to take place there must be three things present
Air
Fuel
Spark
Two types of igniter plugs
Surface discharge plug
Air gap plug
How do you know it’s a surface discharge plug
Has no air gap
Has a centre electrode and ceramic semi-consuctor
How do you know it’s the air gap plug
It has a large air gap and body for spark to cross
Requires potential difference of 25000 volts
Torch ignitor
Provides atomized fuel spray and high energy, surface discharge plug to ignite fuel
Starting cycle for the torch ignitor system
Pic
High energy ignition units
How much ignitors does it have
Has two ignitors
It’s designed to deliver a high voltage, high current discharge at the ignitor plug from a low voltage AC to DC supply
When the electrical supply is disconnected from the HEIU what must you do
How long should you wait for the capacitor to discharge
Disconnect the low-tension lead
Wait atleast 1 minute
What can the ignition system also be used for
Start up
Testing
Relight
Icing conditions
Turbulence
Take off in heavy rain
Maintenance
Stater generator = secruity attachment of clamp - inspect for highvibration damage
Cables = attachment of cables = cables and leads should be examined for damage, contamination, oil
Ignition leads = HT leads become damaged
Igniter/injectors = carbon build up , erosion
Igniters test = tested before each start ( cracking noise )
