CHAPTER 3 GENERATOR SET CONTROLS REPAIR INSTRUCTIONS Section  I.  INTRODUCTION 3-1. General. 3-2. Generator Set Controls Description. This chapter includes repair instructions for the The  generator  set  controls  are  mounted  at  the  rear fault indicator panel and the control cubicle. Test of the set, and provide all monitoring and control procedures for the control cubicle include individual devices  required  to  operate  the  set.  Controls  con- tests  for  the  converter,  control  box,  relay  assem- sist of the fault indicator panel, the control cubicle, bly, frequency meter and transducer, ac wattmeter and the manual throttle control. Refer to the Oper- and ac ammeter. ator and Organizational Maintenance Manual for manual throttle control repair instructions. Section II. FAULT  INDICATOR  PANEL 3-3. Removal, Disassembly and Repair, a. Removal. Refer to Operator and Organiza- tional  Maintenance  Manual  and  remove  the  fault  indi- cator  panel. b. Disassembly. See figures 3-1 and 3-2 and disassemble the fault indicator panel. c.  Repair.    Proceed  as  follows — (1) Clean all components with low pressure compressed air, or wipe clean with dry, lint free cloth. (2)  Inspect  for  broken  fuseholders,  cracked  or broken lamp holders, damaged wire insulation, bro- den wires and bent or broken connector pins. (3) Remove any components that show visual damage, such as broken fuseholder, or broken lamp holder (fig. 3-1). (4)  Replace  circuit  board  if  broken,  cracked or  distorted. (5) Resistors may be checked by breaking con- nection at one end to prevent feedback resistance and  touching  both  ends  with  ohmmeter  probes.  Re- sistors R1 through R10 (fig. 1-2) should read 2. 2K ohms ±10 percent. Resistors  R11  through  R20 should  read  1K  ohms  ±10  percent.  Any  variation in  excess  of  10  percent  indicates  that  the  resistor should  be  replaced. If any connections are opened or bared for test purposes or if any defective com- ponents  are  replaced,  the  affected  area  must  be coated with polyurethane resin to prevent oxidation or other corrosion. The coating must be of a mini- mum thickness of O. 007 inches and air bubble entry into  the  applied  polyurethane  must  be  controlled  so that  the  legibility  of  component  coding  and  identifica- tion  is  not  impaired. The  polyurethane  resin  to  be utilized  will  correspond  to  MIL-I-46058  grade  S, Type PUR. (6)  Unplug  relay  17,  (fig.  3-1)  in  fault  indica- tor panel and check resistance of relay coils with ohmmeter probes across pins 3 and 7. Reading should be 300 ohms ±10 percent. Replace relay if variation  exceeds  10  percent.  Plug  relay  into  cir- cuit  board. (7) Rebuild wiring harness if inspection re- veals 30 percent or more defective wires. Wiring harness  rebuilding  instructions  are  described  in Chapter 5. Otherwise replace damaged wires. 3-4. Reassembly, Testing and Installation. a. Reassembly. See figures 3-1 and 3-2 and re- assemble  the fault indicator panel. b. Testing. See figure 1-2. To test the fault in- dicator panel, proceed as follows: (1) Connect 24Vdc, positive to pin A of ter- minal board. (2)  Connect  24Vdc  negative  to  pin  B  and  case. (3)  Operate  reset  switch.  All  lights  should light. (4) Connect pin C to pin D. Low oil pressure light  should  light. (5) Open C to D connection. Low oil pressure lights should remain on. (6) Connect pin C to pin E. Low oil pressure light should remain on. (7) Operate reset switch. Low oil pressure light should go out and overspeed switch should light. 3-1