TM 55-4920-328-13 Engine Low Oil Pressure (11) Engine Chip Detector (12) Services Inoperative (13) NI Overspeed (14) Engine Low Fuel Pressure (14A) High EGT (15) Nil Overspeed (16) Engine Low Oil Level (17) Water Brake System (18) Aborted Start (19) Water Brake Low Oil Pressure (20) Water Brake BRG H20 (21) Water Brake Low Oil Flow (22) Cooling Tower Low H20 Level (23) The  front  panel  mounts  four  INSTRUMENT/CONSOLE switchlight units with the following lens engraving: 115 VAC 400 Hz (28) Inst DC (29) Console DC (30) 26 VAC 400 Hz (31) The   panel   also   mounts   ENGINE,   ALARM,   and   test switchlight units placarded as follows: Lamp Test (24) ACK (25) Test (26) Engine DC (27) The  rear  panel  of  the  services  panel  assembly  mounts connectors J1, J2, and J3 for connection of this unit with other   electrical   components   contained   in   the   system. The     time     (Ml)     indicator     (10,     figure     1-25)     is     a hermetically-sealed, digital readout, elapsed time indicator  which  displays  total  accumulated  operational time   for   the   system.      The   input   power   required   for operation  of  the  time  indicator  is  provided  by  117v  ac, 60 Hz power from the diesel engine generator set.  Two solder  terminals  are  provided  on  the  rear  face  of  the time  indicator  housing  for  connection  of  input  power. There is no reset function incorporated in the design of the time indicator. 3.    Transducer input monitor alarm assembly 4A2.  The transducer input monitor alarm assembly (32, figure  1-25)  is  located  in  the  lower  part  of  the  cabinet assembly  immediately  below  the  writing  surface.    The rack-mounted   monitor   alarm   assembly   is   19   inches wide, 3.5 inches high, and 16.5 inches deep.  The unit is a   modular,   solid   state   annunciator   subsystem   which senses, indicates, and acknowledges alarm inputs from a  series  of  external  sensors.    The  unit  provides  output signals    for    audible    and    visual    warning    of    out-of- tolerance   operating   conditions   during   a   test.      Seven connectors are installed on the rear panel of the unit for connection    with    other    electrical    components    of    the system.    The  monitor  alarm  assembly  consists  of  four sections:   sequencing,   flasher-audible,   set   point,   and regulation.    Section  1  consists  of  11  dual-sequencing, plug-in  circuit  boards.    Each  circuit  board  operates  two visual    alarm  lamps.    This  unit  monitors  22  separate contact closures and generates output signals to Section 2.      The   flasher-audible   part   of   the   unit   comprises Section   2.      The   section   sensed   input   signals   from Section 1 to cause the audible alarm assembly to sound and   the   appropriate   annunciator   light   in   the   services panel assembly (9) to flash on and off continuously until the   test   technician   takes   action   to   acknowledge   the visual  warning.    Section  3  of  the  unit  contains  the  set point  circuitry  consisting  of  six  plug-in  circuit  boards, each utilizing one contact.  The regulator section of the unit  (Section  4)  contains  two  circuit  boards  which  are conditioned   by   ac   input   signals   to   provide   regulated +12v  dc  and  -12v  dc  voltages  to  Section  3.    When  an out-of-tolerance  condition  is  sensed,  the  monitor  alarm assembly   provides   a   signal   to   an   audible   alarm   unit which sounds to alert the test technician. Simultaneously,   intermittent   signals   are   sent   to   the appropriate ALARM DISPLAY annunciator light to cause the  light  to  flash  on  and  off.    The  light  will  continue flashing until the abnormal condition is cleared, until the ACK  switchlight  unit  (25,  figure  1-25)  is  depressed,  or until    the    system    is    deenergized.        When    the    ACK switchlight  unit  is  depressed,  the  annunciator  light  will come  on  and  remain  continuously  on  and  the  audible alarm will be simultaneously silenced.  The unit may be tested by use of the ALARM TEST switchlight unit. 4.    26  VAC,  400  Hz  power  supply  4A9.    The 26v ac, 400 Hz    power    supply    (41,    figure    1-25)    is located in the lower part of the cabinet assembly which houses   the   services   sub-module   (Unit   4),   below   the transducer   input   monitor   alarm   assembly   (32).      The power supply converts 117v ac, 60 Hz to 26v ac, 400 Hz power.    The  26v  ac  output  is  variable  from  24  to  30 volts;  the  115v  ac  output  is  variable  from  105  to  130 volts.    Frequency  of  the  output  is  variable  from  380  to 420 Hz.  Two meters are installed on the left side of the rack-mounted unit to display output voltages and output current.  A dual knob is centrally located to the right of the  meters.    This  control  allows  precise  adjustment  of the output of the unit.  Output jacks are located on the front panel to provide a source of auxiliary power when required.      A   2-ampere   fuse   is   mounted   on   the   front panel  for  line  protection.    Two  other  MDL-8  fuses  are mounted on the rear of the 1-50