TM  55-1520-240-T 15-7.2  CONTROLS  AND  INDICATORS  FUNCTIONS  TABLE 15-7.2 TABLE 15-7.1 FUNCTION  OF CONTROLS AND INDICATORS ON APU TESTER ITEM NOMENCLATURE FUNCTION 1 SPEED  meter Displays  %  engine  speed  from  0  to  120. 2 Color  coded  LED  indicators a.   BYPASS   (grn) Lighted   -  indicates  voltage  is  applied  to  start  bypass valve. b.  MAIN  POWER  (red) Lighted   -  indicates  main  power  is  on. c.   MALF   (red) Lighted   -  indicates  malfunction  has  occurred  and  unit is  shutdown.  Bite  indication  on  ESU  is  checked  for cause. d.   READY   TO   LOAD   (grn) Lighted  -  indicates  APU  is  ready  to  accept  load. e.   START   COMMAND   (grn) Lighted   -   indicates   start   command   is   initiated, f.   MAX.   AIR   (red) (Not  applicable) g.   ECONO   AIR   (yel) (Not  applicable) h.  START  FUEL  (yel) Lighted  -  indicates  start  fuel  valve  voltage  on approximately  5%  RPM. i.   MAIN   FUEL   (yel) Lighted   -  indicates  main  fuel  valve  voltage  on, approximately  14%  RPM. j.   MAX.   FUEL   (yel) Lighted  -  indicates  max.  fuel  voltage  on, approximately  90%  RPM  +  5  sec.  time  out. k.   OIL   PRESSURE   (yel) Lighted   when   MAIN   POWER   is   lit.   Does   NOT   indicate Oil  Pressure. 1.   BLEED   VALVE   OPEN   (grn) (Not  applicable) m   REMOTE   (red) Lighted  -  indicates  remote  analog  converter  selected. (Actual  magnetic  pickup  and  thermocouple  probe.) 3 MASTER   switch Controls  28  VDC  power  to  Tester  and  ESU. Refer  to  Paragraph  15-7.1  for  location  of  items. ITEM NOMENCLATURE FUNCTION 4 START/   RUN   /STOP   switch Initiates  start  sequence  of  ESU  and  generates  start signal   input   to   tester. 5 BLEED   AIR   OPEN/CLOSE (Not  applicable) switch 6 OVERSPEED   TEST   switch (Not  applicable) 7 MAX.   AIR   switch (Not  applicable) 8 ECONO  AIR  switch (Not  applicable) 9 LOCAL/REMOTE switch Selects  local  or  remote  analog  converter.  LOCAL (down   position)   selects   analog   converter   in   aircraft. REMOTE   (up   position)   selects   analog   converter   in tester.   Always   used   in   the   REMOTE   position. 10 TACH   INPUT   jacks To   monitor   magnetic   pickup   input   and   input simulation   signals. 11 BLEED  VALVE  VOLTS/ (Not  applicable) CURRENT  jacks 12 DIAGNOSTIC   connector (Not  applicable) 13 Connector J5 Output  connector  for  harness  connection  to  APU. 14 Connector J 1 Input  connector  for  harness  connection  to  ESU. 15 Connector J2 Input  /Output  connector  for  harness  connection  to ESU   and   Airframe   harness. 16 TEMP   meter Displays  exhaust  gas  temperature  (EGT)  in  °F  from  0 to   1500. 17 PANEL   Lights Lighted  -  indicates  28  VDC  power  is  available  to tester.   Illuminates   panel   meters. Change 8 15-141