LM2500 GTMs Flashcards
1
Q
Start Sequence
A
- Most remote bearing L/O pressure > 10psig
- Ngg < 3500 rpm
- MRG turning gear disengaged
- EC system reset
- Throttle at idle
- Motor Regulator Valve in the start position; not being used by another engine
- Clutch cover in place
2
Q
GTM Auto shutdowns
During operation
A
- PT inlet gas temp (T5.4) trip: 1625 F
- PT over speed (NPT): 3960 +/- 40 RPM
- GTM L/O pressure low trip: 6 psig
- Flame out trip: < 400 F T5.4 with <50 psig FMP above 4500 RPM Ngg
- GG vibs stop: 7 mils
- PT vibs stop: 10 mils
- Unidentified stop: Throttle above idle with PT speed loss active (PT speed below 100 rpm)
3
Q
5 Main Components of the LM2500
A
- Compressor
- Combustor
- HP Turbine
- Gas Generator
- Power Turbine
4
Q
Connection to MRG and (Synchronizing Self-Shifting) SSS Clutch
A
Aligns the GTMs to the MRG power when the GTM is brought online and automatically disengages a GTM from the power train when secured
- Clutch will engage when shaft speed is =, or > than output shaft speed
- Clutch will disengage when input shaft is rotating slower than output shaft
- Clutch can be locked out, preventing its engagement
4
Q
Standard Engine Configurations
A
- Trail
- Split
- Ful
5
Q
Bleed Air and the GTM
A
8th Stage: Sump pressurization and cooling of the four bearing sumps
9th Stage: Pressurize and cool the PT balance piston in the Turbine Rear Frame (TRF), cool the Turbine Mid Frame (TMF) struts, and LP turbine rotor
13th Stage: Cools the 2nd stage HP turbine nozzles and interstage seals
16th Stage: “Customer bleed air”; Cools the combustor lining and centering the flame within the combustion chamber
