Komatsu 830E-AC Shop Manual page 246

Test Set-up
1. Discharge the battery as follows:
a. Disable the fuel system.
b. Turn all lights and accessories on. Crank the
engine for 10-15 seconds to discharge the
battery.
c. Turn all lights and accessories off.
d. Enable the fuel system.
2. Determine which set point is used on the regu-
lator (27.5, 28.0, 28.5, 29.0). The set point of
the alternator is 28V. Normal range is within ±
0.3V of set point, as shown in Table 10-2.
Table 10-2: VOLTAGE REGULATOR
System Factory
Voltage Setting
27.5
28.0
24
28.5
29.0
Refer to Figure 10-7 for the following steps. Install
meters directly at the alternator, as shown, to elimi-
nate variations in readings due to cable lengths, etc.
3. Open the battery disconnect switch. Remove
the battery cable from the alternator (B+) termi-
nal.
D10-16
Normal
Range
27.2 - 27.8
27.7 - 28.3
28.2 - 28.8
28.7 - 29.3
1. Alternator Under
Test
2. 0 to 400 AMP
Ammeter
3. 0 to 40VDC
Voltmeter
4. Attach the meters as indicated by Figure 10-7.
5. Secure all the test equipment leads to prevent
6. Reconnect the battery disconnect switch.
Battery Charging Alternator
FIGURE 10-7. TROUBLESHOOTING
4. Alternator (B+)
5. Alternator (B-)
6. Truck Batteries
Measure the voltage and amperage at the alter-
nator, not at the batteries or an intermediate
point.
a. Connect the ammeter negative lead to the
end of the cable removed in Step 3. Connect
the ammeter positive lead to the alternator
(B+) terminal.
b. Connect the red lead of a voltmeter to the
alternator (B+) terminal, and the black lead
of the voltmeter to the (B-) terminal on the
alternator.
damage or short circuits when the engine is
started.
Terminal
Ground Terminal
D10003 07/06