TP-6255 7/06
63
Section 8 Component Testing and Adjustment
Section 8 Component Testing and Adjustment
8.1 Theory of Operation
These generator sets utilize a rotating-field alternator to
produce AC voltage. Upon activation of the generator
master switch, DC current from the battery magnetizes
the rotor (field). When the magnetized rotor rotates
within the stator windings, an electrical voltage develops
within the stator. As engine speed and generator output
increase, the SCR module feeds rectified stator output
current to the rotor through the exciter to increase the
strength of the rotor field. As the rotor field increases in
strength, generator output also increases.
The
ADC 2100 monitors the generator output voltage
through leads 11 and 44 (for 1-phase models) or leads
V7, V8, and V9 (for 3-phase models) and adjusts the DC
current from the SCR module to the rotor to meet load
requirements. See Figure 8-1.
8.2 Separate Excitation
To determine the cause of no- or low-AC output, refer to
the troubleshooting flowchart in Figure 8-2.
Before
beginning the test procedures, read all of the safety
precautions at the beginning of this manual. Many of the
test procedures include additional safety precautions.
Check the condition of the alternator fuse before
performing the separate excitation procedure.
The
inline fuse is located in lead 55 of the wiring harness.
See Figure 8-1. If the fuse is not blown, use the following
procedure to separately excite the generator using an
external voltage source (a 12-volt automotive battery).
Separately exciting the generator can identify faulty
voltage regulation by the ADC 2100 or reveal a running
fault in the rotor and/or stator. An external power source
duplicates the role of the voltage regulator and excites
the generator field (rotor). A generator component that
appears to be in good condition while stationary may
exhibit a running open or short circuit while moving.
Short circuits can be caused by centrifugal forces acting
on the windings during rotation or insulation breakdown
as temperatures increase.
FP
11
3
4
55
2
1
44
7
5
2
8
6
1. Fuse
2. Power lead (55)
3. Excitation to rotor
4. Exciter
5. Rectifier module
6. Main field (rotor)
7. Stator windings
8. Sensing leads (11--44)
66
11
1
ADC
2100
SCR
4
(--)
(+)
AC1
AC2
G1
G2
44
66
66
55
55
G
F+
FN
FP
FN
3
AC
F +
F --
AC
AC
Figure 8-1
Generator Schematic
(Single-Phase Model Shown)
No Generator Output
Separate Excitation
Output within
Specifications
Check Rotor
Check Wiring, Fuses,
SCR Module and
ADC 2100
Check Stator
TP563273
Erratic or No Output
Figure 8-2
General Troubleshooting
Summary of Contents for 6.5-27EFOZD
Page 1: ...Marine Generator Sets Models 8 32EOZD 6 5 27EFOZD TP 6255 7 06a Service ...
Page 12: ...TP 6255 7 06 12 Service Assistance Notes ...
Page 22: ...TP 6255 7 06 22 Section 1 Specifications Notes ...
Page 28: ...TP 6255 7 06 28 Section 3 Intake and Exhaust System Notes ...
Page 62: ...TP 6255 7 06 62 Section 7 Controller Notes ...
Page 78: ...TP 6255 7 06 78 Section 8 Component Testing and Adjustment Notes ...
Page 92: ...TP 6255 7 06 92 Section 10 Wiring Diagrams Notes ...
Page 100: ...TP 6255 7 06 100 ...
Page 101: ...TP 6255 7 06 101 ...
Page 102: ...TP 6255 7 06 102 ...
Page 103: ...TP 6255 7 06 103 ...