6-10. Malfunctions in the ac system should be traced by verifying that the ac power
switch S101, auxiliary contacts of relay K101, and the circuit breaker closed indicator
light DS5 are functioning properly.
6-11. If power is not available at the aircraft terminals, the ac generator G101, volt-
age regulator VR101, overvoltage relay K102, ac power contactor K101, limiter
CLl0l, and the ac power cable should be checked.
6-12. Problems with proper readouts of ac voltages and amperes should be traced by
checking the ac selector switch S102, current transformers CT101, CT102, and
6-14. Improper operation of the APU control system may be traced to the APU ex-
haust thermal switch. The switch may be checked with a Jet-Cal test instrument, or
e q u i v a l e n t .The normally closed switch contacts should open at 1040 to 1070F for
APU Model T-62T-2, and 1070 to 1090F for APU Model T-62T-2A.