TM  55-4920-403-20&P NOTE Be   sure   to   note   which   wires   are   con- nected  to  which  number  contact.  Refer to   the   shelter   wiring   diagram   in   drawing 4920-EG-056  (figure  D-2)  for  assistance. Install   the   new   receptacle   by   inserting and  securing  the  wires  first.  Then  install the   mounting   hardware   and   reinstall   the power  inlet  panel  cover. (2)  The   ground   stud   (item   28,   figure   D-2) may  be  replaced  by  de-energizing  the  shelter,  re- moving   ground   stake   wire   and   removing   the power  inlet  box  cover  as  previously  described. As  an  extra  safety  precaution,  remove the shelter power cable from the power inlet  connector. (3)  Loosen  the  nut  securing  the  stud  and  re- move  the  damaged  stud.  Clean  away  any  build  up of   corrosion   then   install   a   new   ground   stud,   se- cure   the   inside   ground   wire,   and   tighten   the mounting   nut.   Replace   the   power   box   cover,   fas- ten   the   ground   stake   wire   outside,   and   reconnect the  shelter  power  cable. (4)   Replacement   of   the   weatherproof   outlet cover  (item  24,  figure  D-2)  should  be  preceded  by turning   off   the   circuit   breaker   supplying   power   to the  outlet.  Remove  the  screw  holding  the  weather- proof   cover   in   palce   and   replace.   If   the   outlet (item   26,   figure   D-2)   needs   replacement,   de-ener- gize   the   shelter   and   remove   the   power   inlet   box cover   as   previously   described.   Remove   screws and   nuts   holding   the   outlet   to   the   panel.   Remove the   wires   from   the   connector   and   discard   the damaged  connector.  Install  wires  on  the  new  con- nector,   install   mounting   hardware,   and   weather- proof   cover   plate.   Reinstall   power   box   cover   and energize  the  shelter. (5)   Repairs   to   the   power   inlet   panel should  be  limited  to  replacing  loose  rivets  and  re- pairing  dents  and  minor  sheet  metal  punctures. d.   Circuit   Breaker   Panel. (1)   In   the   unlikely   event   the   entire   circuit breaker  panel  (items  29  and  30,  figure  D-2)  re- quires  replacement  due  to  damage  to  the  case  or electrical  damage  to  the  bus  bars,  a  new  panel may   be   installed,   De-energize   the   shelter   and   re- move   the   power   cable   from   the   power   inlet   con- nector.   Use   a   trouble   light   to   illuminate   the   shel- ter.   Remove   the   cover   (item   30,   figure   D-2)   and disconnect  all  wires, NOTE Put   a   masking   tape   label   on   each   wire as  it is  disconnected  to  aid  in  proper  re- assembly. (2)  Loosen   and   remove   all   conduit   con- nector  retaining  nuts.  Remove  four  screws  (item 111,   figure   D-2)   holding   the   panel   to   the   backing plate.   Install   new   paneI   using   the   sheet   metal screws   removed   from   the   old   one.   Punch   out   ap- propriate   knock-outs   and   insert   conduit   con- nectors.   Install   conduit   connector   retaining   nuts. Install   serviceable   circuit   breakers   from   the   old panel  or  new  ones  by  snapping  them  into  place  in the  same  position  as  on  the  old  panel.  Connect wires  as  previously  labeled  and  refer  to  the  shelter wiring   diagram   in   drawing   4920-EG-056   (figure   D- 2).   Replace   breaker   panel   cover   and   re-energize shelter.   Check   all   circuits   for   proper   operation. e.  Circuit   Breakers.   Circuit   breakers   (items 31,  32  and  33,  figure  D-2)  are  replaced  when  they become   physically   damaged   or   fail   electrically   to operate   properly.   De-energize   shelter   and   remove shelter   power   cable.   Illuminate   the   shelter   with   a trouble   light.   Remove   circuit   breaker   panel   cover (item   30,   figure   D-2).   Disconnect   the   wire   at- tached   to   the   circuit   breaker   and   remove   the breaker   by   pulling   outward   and   to   the   side.   Snap in   a   proper   size   replacement,   reconnect   the   wire and   reinstall   panel   cover.   Re-energize   the   shelter and   check   circuit   for   proper   operation. f.   ECU   Power   Cable. (1)   Check   cable   (item   44,   figure   D-2)   for signs  of  fraying,  cracks,  etc. All  repairs/replacement  to  the  ECU  ca- ble/connector should be performed with the   30   amp   3   phase   circuit   breaker turned off. (2)   The   power   connector   (item   27,   figure may  be  repaired  by  resoldering  broken  wires. D-2) Minor  damage  to  the  cable  jacket  may  be  repaired by   wrapping   with   plastic   electricians   tape.   To-re- place   the   cable   and   connector,   remove   the   box cover  plate  (item  22,  figure  D-2)  and  disconnect the  cable  wires.  Loosen  the  cable  clamp  (item  35, figure   D-2)   and   remove   cable.   Install   new   cable and   tighten   clamp.   Connect   cable   wires   to   shelter wiring   and   solder   connector   (item   27,   figure   D-2) to   free   end   of   cable   in   accordance   with   shelter wiring   diagram   in   drawing   4920-EG-056   (figure   D- 2).   Test   connector   with   an   ohmeter   for   shorts   be- tween   contacts. Change  1 3-3