CHAPTER 2 GENERAL  MAINTENANCE  INSTRUCTIONS Section I. REPAIR PARTS, SPECIAL TOOLS AND EQUIPMENT 2-1. Tools and Repair Parts, Equipment There are no special tools or equipment required to perform  intermediate  (field)  (direct  and  general support) and depo t maintenance on generator sets Models MEP006A, MEP105A and MEP115A. A listing  of  recommended  tools  and  support  equipment required to perform the maintenance operations described in this manual are contained in Table 2-1. 2-2. Direct Support General Support and Depot Maintenance Repair Parts. Direct and general support and depot maintenance repair parts are contained in the technical manual listed in Appendix A of this manual. 2-4.   General. 2-3.  Specially  Designed  (Fabricated)  Tools  and Equipment. A   breakout   cable   is   required   to   trouble- shoot   the   electric   governor   system   of   MEP   - 114A.   The   breakout   cable   is   used   to   gain access   to   the   governor   Control   Unit’s MS3106R20-29   connector.   Figure   2-0 g i v e s    f a b r i c a t i o n    i n s t r u c t i o n s    f o r    t he breakout   cable. Section  II.  TROUBLESHOOTING This  section  provides  information  useful  in diagnosing  and  correcting  unsatisfactory  opera- tion  or  failure  of  the  engine  generator  set  and its  components. Malfunctions which may occur are listed in table 2-2. Each malfunction stated is followed  by  a  list  of  probable  causes  of  the trouble.  The  corrective  action  is  described  oppo- site the probable cause. 2-5. Troubleshooting Chart. Table 2-2 lists generator set troubleshooting mal- functions,  probable  causes  and  corrective  action. 2-6.   Diagrams. Wiring,  schematic  and  trouble  shooting  diagrams  for the generator set are listed in the List of Illustrations in the Table of Contents. Refer to the Operator and Organizational  Maintenance  Manual  for  diagrams  not located in this manual. Section III. RADIO INTERFERENCE  SUPPRESSION 2-7. General Methods Used to Attain Proper Suppression. Essentially, suppression is attained by providing a low resistance path to ground for the stray currents. The methods used include grounding the frame with  bonding  straps,  grounding  the  engine-generator set, and the use of capacitors. 2-8. Testing of Radio Interference Suppression Components. Test the capacitors for leaks and shorts on a capacitor  tester:    replace  defective  capacitors.  If test equipment is not available and interference is indicated,  isolate  the  cause  of  interference  by  the trial  and  error  method  of  replacing  each  capacitor in  turn  until  the  cause  of  interference  is  located and  eliminated. 2-9. Interference Suppression Components. a.  Primary  Suppression  Components. components,  RFI  capacitors,  whose  primary  pur- pose  is  interference  suppression  are  the  three capacitors found on the generator side of CB2, main line contarctor and the three on the input leads to the engine-generator  sets  load  bank.  Their  description, location and removal are covered in the Operator and Organizational  Maintenance  Manual. Three  suggested  methods  of  grounding  the  engine- generator set, instrumental in passing RFI induced currents  to  ground  are  illustrated  in  the  Operator and Organizational Maintenance Manual. b.  Secondary  Suppression  Components.  The components, RFI capacitors whose secondary pur - pose is interference suppression are the components contained within the excitation system assembly. Testing of the RFI filter A201 is described in para- graph 8-12  b  (3),  utilizing  figure  1-8  schematic  dia- gram,  excitation  system  assembly.  Refer  to  figure 8-1 for disassembly of the relay table which includes the excitation system assembly, and figure 8-15 for the excitation system assembly. Change  9  2-1