Komatsu 830E-AC, Shop Manual

Page: 462 / 1085

E3-32 AC Drive System Electrical Checkout Procedure 10/06 E03018
(Version 21 Software)
In the following step, exhaust air from grid vents
may be very hot.
4. Put the directional control lever in NEUTRAL and
depress the accelerator pedal to just pick up
contactor RP1. This should occur at
approximately 1150 rpm.
Check for hot air flow from both front sections of
the retarding grid.
Check for air flow from the rectifier air exhausts
on the back of the control cabinet.
On the PTU, verify that the values for BLWR1
and BLWR2 are balanced but opposite polarity.
NOTE: If the HPADJ value is fixed at zero and the
ENGLOAD% value is fixed at 50% (or 5.0V if using an
analog load signal), it is an indication that the PWM
engine load signal is not getting to the PSC. Check for
Event 63 (Engine Load Signal) on the DID panel. Refer
to Troubleshooting for more information.
5. Depress the accelerator pedal to pick up
contactors RP1 and RP2. This should occur at
approximately 1375 rpm.
6. Let up on the accelerator pedal just enough so
that contactor RP2 drops out but contactor RP1 is
still picked up. This should occur at approximately
1375 rpm.
NOTE: Some trucks are not equipped with contactor
RP3.
7. Depress the accelerator pedal to pick up
contactors RP1, RP2 and RP3. This should occur
at approximately 1550 rpm.
8. Warm up the engine until the engine coolant
temperature stabilizes. Then fully depress the
accelerator pedal to pickup all the RP contactors.
The CHOP value on the PTU should be be 25%
at approximately 1900 rpm.
9. Record the PTU screen while viewing the screen
during full load.
Under the “Save” menu, select “Single
Snapshot”, then click “Save”.
To view the recorded screen, under the “View”
menu, select “Screen Relay”, the highlight the
file and click “Open”.
10. 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 loading. 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.
11. The Self Load Engine Test screen should be
recorded and the values compared to values that
are calculated to account for parasitic losses at
the elevation of the test site and ambient
temperature during testing as follows:
a. Output horsepower should be 2700 HP ±5% @
1900 +10/-15 rpm.
b. Requested rpm from GE must be 1900 rpm.
c. Refer to Figure 3-17 for parasitic losses curve.
Read the parasitic losses from the graph
based on ambient temperature and altitude.
Add the value on the graph to the delivered
HP to GE and compare that to the “-5%”
value at the rpm rated tolerance (i.e. 2612
HP + value from graph = corrected HP).
Manual Offset HP Output Adjustment:
12. If it isnecessary to troubleshoot HP problems, use
the following procedure:
With loadbox initiated, enter a + or - offset value
in the “HP Offset” field.
Click the “HP Offset” box.
13. Perform the load test again.
Return the offset to 0.0
Click the “HP Offset” box.
Click “EXIT LDBX” to exit the Self Load Engine
Test screen.
14. Allow the engine to cool down until the engine
temperature and pressure gauges show normal
operating values.
15. Turn the rest switch ON.
16. Turn the key switch OFF. Allow approximately 90
seconds for the steering accumulators to bleed
down.
17. Remove the jumper from the fan clutch control
circuit
18. Record all data to create a truck record for future
comparison.