TM 5-3895-374-24-1 Maintenance After a Fault Has Occurred WARNING  All  equipment  must  be  de-energized, disconnected   and   isolated   to   prevent   accidental contact with live parts Check voltage on all control terminals   and   on   all   line   and   load   terminals   of circuit breakers, disconnect switches, and starters or   contactors   before   working   on   this   equipment Only qualified personnel should be involved in the Inspection   and   repair   procedure,   and   all   safety procedures must be observed. M-39  The   excessive   currents   occurring   during   a   fault may  result  in  structure,  component  and/or  bus  or conductor  damage  due  to  mechanical  distortion, thermal damage, metal deposits or smoke. After a fault,   correct   the   cause   of   the   fault,   inspect   all equipment   and   make   any   necessary   repairs   or replacements   before   putting   the   equipment   into service again. Be sure all replacement parts are of the     proper     rating     and     are     suitable     for     the application If in doubt, consult your local Square D field office. The complete maintenance procedure (Sections M-1 through M-38, pages 14 through 23) should be followed after any fault The following are additional Items to watch for In these circumstances. M-40 Locate and correct the cause of the fault If the fault occurred    downstream    from    the    motor    control center, appropriate maintenance should be carried out on all equipment involved. M-41  Enclosure     -     External     evidence     of     enclosure damage usually indicates damage within. Extensive  damage  will  require  replacement  of  the enclosure    parts    and    the    enclosed    equipment. Follow  Maintenance  Procedures  M-2  through  M-3 (page 14) Replace any parts that are damaged or deformed  Pay  particular  attention  to  door  hinges and    door    closing    hardware    Inspect    the    area around  any  damaged  units  (both  inside  and  out) for displaced parts from the damaged unit. M-42  Bus   Bars   and   Incoming   Line   Compartments   - Follow  Maintenance  Procedures  M-4  -through  M- 10   tightening   all   electrical   connections   to   their proper torques. Replace any deformed bus bars or connectors as well as any showing signs of arcing damage Inspect for cracked and/or burned insulators. M-43   Units   -      Follow   Maintenance   Procedures   M-11 through M-36. 1.    Examine the disconnect means for evidence of possible damage See that the operator mechanism properly turns ’ON" and "OFF" the disconnect Exercise the push-to-trip feature on circuit  breakers  and  be  sure  that  the  operator properly resets the breaker. 2.    Check   that   the   door   interlock   prevents   the opening of the unit door while the disconnect is in  the  "ON"  position.  See  Section  1-20  (page 13) for interlock operation 3. Check     motor     starters     for     any     damage Replace  contacts  and  contact  springs  if  the contacts are welded or show heat damage If deterioration  extends  beyond   the   contacts. replace the entire contactor or starter. 4 Replace    the    complete    overload    relay    if thermal units have been burned out. If there are  any  Indications  of  arcing  or  burning  on the overload relay, also replace it. 5. Inspect   all   fuses   and   fuse    clips.    Always replace all fuses in a set even if only one or two are open circuited. 6. Check    all    conductors    and    other    devices within the units for any signs of damage. M-44  Complete    an    insulation    test    (Procedure    M-37, page    23)    before    attempting    to    put    the    motor control center back into service. M-45  Complete  pre-operational  check  list  Procedure  1- 16 (page 12). M-46  Re-energize the equipment following Procedure 1- 17 (page 12). (Page 3-141)