TM5-6115-593-34 NAVFAC P-8-631-34 TO-35C2-3-463-2 component. Components are replaced by carefully unsoldering them from the printed circuit board, and carefully soldering new component into place. WARNING BEFORE    STARTING    ANY    MAINTENANCE PROCEDURE, SET MAINTENANCE LOCKOUT SWITCH TO LOCKOUT. DISCONNECT NEGATIVE CABLE FROM BATTERIES.   REMOVE   EXTERNAL   POWER BY   OPENING   CB101   (EXTERNAL   POWER CIRCUIT  BREAKER)  AND  DISCONNECTING POWER   CABLE   FROM   RECEPTACLE   J101 (120V RECEPTACLE). CAUTION Do   not   apply   excessive   heat   when soldering or unsoldering components. b. Replacement. (1) Removal.    The  voltage  regulator  (48, figure  4-1),  is  mounted  in  the  AC-DC Control Box Assembly enclosure. Open AC-DC control box door, and remove voltage regulator as follows: (a) Disconnect    and    tag    all    wires from  voltage  regulator  terminal board,    including    grounds    for shielded cables. (b) Remove   four   screws   (46)   and washers   (47)   securing   voltage regulator.          Remove     voltage regulator assembly. (2)   Installation. (a) Install voltage regulator assembly (48, figure 4-1), to the AC-DC   control   box   enclosure with four screws (46) and washers (47). (b) Connect     wires     and     shielded cable   grounds   to   the   voltage regulator assembly terminal board     and     chassis.     Remove tags from wires . Section V.  PANEL COMPONENT BASE ASSEMBLY 4-21.  GENERAL.  The panel component base assembly (43,   figure   4-1)   is   located   in   the   AC-DC   control   box assembly   enclosure.      It   contains   the   motor-operated potentiometers P4 and P5, a shunt, two 24V DC relays K1  and  K50,  an  AC-DC  control  relay  TB9,  and  time delay   modules   TD1   and   TD3.      All   components   are directly mounted to the shelf and interconnected with a wiring  harness.    Relays  K1  and  K50  are  plug-in  type relays. 4-22.  SHUNT.  The shunt (6, figure 4-10), is repaired by replacing  the  entire  assembly  which  is  attached  to  the shelf with two screws (5). 4-23.  RELAYS K1 AND K50.  Relay K1 is the run-stop relay,   and   relay   K50   is   the   battle   short   relay.      Both relays  (7,  figure  4-10),  are  six-pole,  double-throw  type relays   with   four   poles   normally   open   and   two   poles normally closed.  Test and replace as follows: a. Test.  To test relays K1 and K50, connect a 24V  DC  power  source  and  a  SPST  switch as shown in figure 4-11. (1) Close SPST switch. With an ohmmeter,  check  for  an  open  circuit between     terminals     1     and     2     and terminals  13  and  14.    Meter  should indicate  continuity  between  terminals 3   and   4,   terminals   5   and   6,   and terminals 11 and 12. (2) Open SPST switch, With an ohmmeter, check for continuity between     terminals     1     and     2     and terminals  13  and  14.    Meter  should indicate     an     open     circuit     between terminals 3 and 4, terminals 5 and 6, and terminals 11 and 12.  If relays fail this    check,    repair    or    replace    the defective relay. b. Replacement.  Relays K1 and K50 are plug- in  type  relays  mounted  on  the  component assembly panel 4-16