NUT-JAM 6F0612 - Caterpillar

Illustration 1 g00555151
PMG Generator Wiring Diagram
(CR1 through CR6) Rectifiers
(CR7) Varistor
(L1) Exciter field (stator)
(L2) Exciter armature (rotor)
(L3) Main field (rotor)
(L4) Main armature (stator)
(L5) Pilot exciter armature
(PM) Permanent magnet
(RFA) Rotating field assembly
(CST) Customer supplied transformer
(T1, T2, T3) Generator terminals and/or generator leadsThis section provides probable causes to a known problem. There may be several probable causes to each problem. Specific inspections or tests are recommended to help isolate the damaged component. The generator is a component of the generator set. The generator should be tested with the entire system. The voltage regulator's service manual provides tests to determine if the generator is the cause of a generator set malfunction.A problem must be identified and defined before the problem can be corrected. After you identify the problem, refer to Table 1.The following procedure should be used to identify the problem:
Perform Visual Checks to help identify the problem.
If previous tests were performed from the voltage regulator service manual, use the test results to help identify the problem.
Perform the Generator Functional Test. The Generator Functional Test will help identify the problem.Visual Checks
A visual inspection of the generator set can detect possible causes of a malfunction. Inspect all wiring for worn insulation or missing insulation. Ensure that all wire terminal connections are tight. Also ensure that all wire terminal connections are not corroded. Discolored electrical components indicate that the item has been greatly stressed. A large percentage of electrical problems are caused by mechanical defects. Carefully inspect the total installation. Keep the mechanical defects separate from the electrical defects.Problem List
Table 1
PROBLEM PROBABLE CAUSE REFERENCE
All Phase Voltages Are Too Low. Damaged diodes (CR1 through CR6) "Rotating Rectifier - Test"
Damaged exciter armature (Rotor - L2) "Winding - Test"
Damaged exciter field (Stator - L1) "Winding - Test"
Damaged PM armature (L5) "Winding - Test"
Damaged varistor (CR7) "Varistor - Test"
The Phase Voltages Are Not Equally Balanced. Damaged main armature (Stator - L4) "Winding - Test"
The Phase Voltages Do Not Change With Engine Speed. Damaged diodes (CR1 through CR6) "Rotating Rectifier - Test"
Damaged Exciter armature (Rotor - L2) "Winding - Test"
Damaged exciter field (Stator - L1) "Winding - Test"
Damaged PM armature (L5) "Winding - Test"