(3) Press 400  Hz GEN T1 circuit breaker to IN position. (4) Set DC BACK-UP to ON. Digital voltmeter will   indicate   approximately   23   vdc.   If   not,   see troubleshooting  Table  4-7. (5) Disconnect test equipment from test set. e.  Lump  Circuit. (1) Pull 400 Hz GEN T1 circuit breaker to OUT position  and  set  GEN/PMG  VOLTS  switch  to  T1. (2) Connect test equipment as shown in Figure 4-2 (DC power supply ON or OFF). Lamps can be checked with 28 vdc or 115 vac applied. (3) Pull 400 Hz GEN T1 circuit breaker to IN posi- tion and adjust AC power supply to 115 ac. (4) Press  all  test  indicator  lamps.  Indicator  lamps will  light  when  pressed.  If  not,  see  troubleshooting Table 4-7. (5) Disconnect all test equipment. f. Voltage Regulator Test Circuit. (1) Pull 400 Hz GEN T1 circuit breaker to OUT position. (2) Set all test switches to down or OFF except TEST   SELECT   to   START   TEST   and   GEN/PMG VOLTS to T1. (3) Connect J1 pins W and X together with jumper lead and connect digital voltmeter between J1 pins f (+) and h (–) on test set. — (4) Connect test equipment as shown in Figure 4-2 (DC power supply not connected). (5) Press 400 Hz GEN T1 circuit breaker to IN position and set BACK-UP DC power and GEN switches to ON. (6) Reset and SIM CONT indicator lights will light and  digital  voltmeter  will  indicate  approximately  22.3  vdc. If not, see troubleshooting Table 4-7. (7) Disconnect all test equipment and set test set switches to down or OFF. (8) Remove jumper lead from J1 pins W and X. g. FIELD AMPS/REG VOLTS Meter Circuit. (1)  Pull  400  GEN  T1  circuit  breaker  to  OUT position. (2) Connect  jumper  lead  to  J1  connector  between pins g and X and set DC BACK-UP switch to ON. — TM 55-4920-410-13&P (3) Connect test equipment as shown in Figure 4-2 (DC power not connected). (4) Set 400 GEN T1 circuit breaker to IN position and READ REG BUS VOLTS-FLD CUR switch to UP position. (5) Adjust AC power supply for a 30V indication on FIELD   AMPS/REG   VOLTS   meter.   If   not,   see troubleshooting  Table  4-7. (6) Disconnect jumper lead from J1 pins g and X and remove AC power supply. Connect test equipment as shown in Figure 4-4. (7) Set READ BUS VOLTS-FLD CUR switch to down position and TEST SELECTOR to START TEST. (8) Adjust DC power supply for a 1 AMP indication on FIELD AMP/REG VOLTS meter. Digital voltmeter will   indicate   between   8   and   12   mvdc.   If   not,   see troubleshooting  Table  4-7. (9)  Disconnect  all  test  equipment  and  set  test switches to down or OFF position. h. CT  Current  Meter  and  Current  Transformer Circuit. (1) Connect  test  equipment  as  shown  in  Figure  4-5. Observe that 400 GEN T1 circuit breaker is OFF. (2)  Position  test  set  controls  as  listed  in  (a)  through (e) below: (a) (b) (c) (d) (e) (3) adjust dc (4) TEST SELECT switch to AØ. CT CUR READ switch to UP. GEN/PMG VOLTS switch to T1. 400 GEN T1 to IN position. All Other Switches to down or OFF. Adjust resistance standard to 3300 ohms and power supply to 28 vdc. Adjust AC power supply for 115 vac at 400 Hz as indicated on GEN/PMG VOLTS and FREQUENCY Meters.  CT  TEST  CURRENT  meter  will  indicate between 0.9 and 1.1 made. If not, see troubleshooting Table 4-7. (5) If voltage is checked at each TEST SELECT switch BØ GEN CT-J1 pin L, CØ GEN CT-J1 pin M, AØ DPCT-J1, BØ DPCT-J1 pin P, CØ DPCT J1 pin Q results will be as indicated in (4) above. If not, see troubleshoot- ing  Table  4-7. (6) Disconnect all test equipment from test set. (7) Connect test leads to J1 connector H and G to digital  voltmeter  and  connect  DC  power  supply  leads  to J1 connector pins S ( -) and J (+). (8)  Set  TEST  SELECTOR  to  FL  REG.  Digital voltmeter will indicate approximately 3 ohms. If not, see troubleshooting  Table  4-7. 4-7