Komatsu 830E-AC, Shop Manual

Page: 464 / 1085

E3-34 AC Drive System Electrical Checkout Procedure 10/06 E03018
(Version 21 Software)
TROUBLESHOOTING
PVM Optimum Load Curve Handshaking
Troubleshooting
NOTE: A value of less than 0.5VDC or more than
9.5VDC on circuit 72E indicates a failure.
1. With the engine off, key switch ON and control
power switch ON, measure the voltage between
the 72E (+) lead and the 72R (-) lead.
The voltage should be 5.0VDC.
a. Jumper circuit 22FO to ground and verify
voltage on 72E to 72R changes to 7.0VDC.
b. If the voltage is 0VDC, verify that the
connections to the PVM are correct and that
circuits 439 and 11SL (connected to CN P382
positions 5 and 40) are 24VDC.
2. With the engine running and under load, and the
key switch and control power switch ON, check
the voltage at 72E (+) to 72R (-).
The voltage should be 5.0VDC.
a. Check the PVM diagnostic connector P381.
b. Verify that the voltage between position A to B
is 8 to 11VDC. A reading of 0VDC indicates
that the 1939 transmission line failed. Check
1939 wiring.
c. Verify the voltage between position C to B is 8
to 11VDC. A reading of 0VDC indicates that
the PVM has failed only if the voltage from
position A to B is correct and the filtering circuit
is correct. Check the filtering circuit resistors
and capacitors connected to P383 positions 12
and 20 and P382 position 33 mounted on
diode board DB1.
3. If both Step 1 and 2 are 0VDC, then circuit 439 or
11SL or both are incorrect.
Allow adequate time for link voltage to drain down
before opening the control cabinet to perform the
following checks or repairs.
Phase Module and Chopper Module
Troubleshooting
1. To troubleshoot a phase module or chopper
module, stop the engine and turn the rest switch
OFF. Connect the serial communication cable
from the PTU to the PSC panel and access the
PSC Manual Test screen.
2. Click the appropriate GD1E or GD2E signal in the
“Digital Output” field and turn it ON. (GD1E turns
on all Inverter 1 phase modules and chopper
module 1. GD2E turns on all Inverter 2 phase
modules and chopper module 2.)
3. Disconnect the gray fiber optic cable on the phase
module or chopper module that is being checked.
In the following step, DO NOT look directly at the
red light. Eye damage could result.
4. If a red light is visible out of the gray receptacle on
the gate driver module, the phase module or
chopper module is OK.
5. If a red light is not visible, disconnect the round
power supply harness from the gate driver
module.
6. Check the AC voltage in the two pins in the
harness. There should be 100 VAC square wave
on the harness. The actual reading on the VOM
will depend on the meter and how it is designed to
measure AC voltage. Most meters read less than
100 volts. Normally, there will either be proper
voltage on the harness or no voltage at all.
7. If there is no voltage, troubleshoot the appropriate
gate driver power converter or the harness. See
“Gate Driver Power Converter Test” earlier in this
section.
8. If there is voltage, reconnect the harness and
disconnect the gate lead on the “G” terminal.
10. If there is a red light visible with the gate lead
disconnected, there is a short and the phase
module or chopper module must be replaced.
11. If a red light is not visible with the gate lead
disconnected, the gate driver module is faulty and
must be replaced. All the gate driver sections for
phase modules and chopper modules are alike
and interchangeable. The red-covered and white-
covered gate driver modules are interchangeable
where mounted by the six cap screws to the
cooling tubes of the phase module or chopper
module.