Komatsu 930E-2, Shop Manual

Page: 228 / 739

NOTE: If the “HP ADJ” value is (-)400 it is an indication
that the zero to ten volt engine command is not getting
to the PSC (Circuit 72E and 72R). Refer to “PVM
Optimum Load Curve Handshaking Troubleshooting
Test” for additional troubleshooting information.
In the following step, air exhausted from grid vents
can be very hot.
5. Without touching them, check for air flow from the
grid blowers as follows:
a. Increase engine RPM until two RP contactors
pickup.
1.) Hot air should be felt from one front section
of the grid.
b. Reduce RPM to idle and then increase RPM to
pickup two RP contactors.
1.) Hot air should be flowing from the other front
section of the grid.
6. Warmup engine with two RP contactors picked up
until the engine coolant temperature stabilizes.
7. Compare values displayed on the Loadbox Test
Screen with the sample screen in Figure 3-11.
8. Fully depress the accelerator pedal to pickup all
three RP contactors.
9. Compare the values on the loadbox screen with
the values shown in the sample screen in Figure
3-12.
10. Record the Loadbox Screen on the PTU as fol-
lows:
a. While viewing the loadbox screen during full
load:
¤ Press the {F2} key
¤ Arrow down to “record” and press {enter}
¤ Type a filename and press {enter}
11. Note the “ENGLOAD” value On the screen:
If the value is 5 volts during load testing,
loading is satisfactory.
If the value is below 5 volts, the electrical
system needs to remove horsepower load-
ing. (This is an indication of a weak engine.)
If the value is above 5 volts, the electrical
system needs to load the engine more.
(This is an indication of a strong engine.)
FIGURE 3-11. SELF LOAD TEST SCREEN, RP1 & RP2/3 PICKED UP
E3-32 AC Drive System Electrical Checkout Procedure 3/01 E03015
(Release 17 Software)