TM 5-6115-434-12 Table 3-5.  Sequence of events during performance check-Continued Step Condition Power unit Indication Adaptor indication Remarks 11 Engine reaches Under frequency arm- If not, diode (CR8) 95 percent ing relay (K6) en- failed, or under governed speed ergizes to open cir- frequency arming -Continued cuit which bypasses relay (K6) failed. low oil pressure switch during starting. Engine continues to If not, low oil pressure run. switch failed to ac- tuate. K7 400 lamp illumi- If not, under frequency nates (K7 does not arming relay (K6) energize-no ground). contacts open, emer- gency switch (S6) contacts open or 400 Hz main contac- tor switch (S2) con- tacts open. K8 load contactor lamp If not, under frequency illuminates (K8 does arming relay (K6) not energize-no contacts open, emer- ground). gency switch (S5) contacts open or 400 Hz main contactor switch (S3) con- tacts open. 12 Engine speed Fuel pressure drops If not, and engine con- reaches about to about 120-150 psi. tinues to accelerate 102 percent to 110 percent and governed speed shuts off, governor (408 cps- malfunctioned. governor con- If not, and fuel pres- trols speed or sure high, but engine engine). operates slightly low in speed, and turbine temperature about 275-310C (530 to 590F) fuel atom- izer or flow divider clogged. If not, and fuel pressure high and turbine discharge temperature more than 325°C (615F) compressor or turbine rub, generator or other accessory failed, or plenum air leak. Exhaust gas tempera- If not, check exhaust ture about 270C- gas temperature in- 320°C (518°F-608 F) dicator calibration (Normal no-load ex- and circuit resistance haust gas temperature.) (8 ohms). Control air pressure ap- If not, check for con- proximately 33 psig trol air leak in lines, (depending on am- ruptured accelera- bient conditions tion limiter diaphragm, and load). or thermostat. 3-26