Komatsu 830E-AC Shop Manual page 417

• DC Link Capacitance Test - This test will run once
every 24 hours when conditions allow, normally
after a VI-test during the normal power-up
sequence. This test can also be run from the DID
panel to aid in troubleshooting. During test
execution, engine speed is set to 1500 rpm and
the DC link is charged to 120 VDC. The engine is
then returned to idle while the DC link is allowed
to discharge to 100 VDC. Total link capacitance is
then calculated using the time it took to
discharge.
If capacitance is getting low, but is still OK, event
70 is logged. If capacitance is below the
minimum allowable level, event 71 is logged and
the truck is restricted to 10 MPH. If the test is not
able to be completed after numerous attempts,
event 72 is logged, indicating a problem in the
truck's ground detection circuit, and truck speed
is limited to 10 mph.
Initiated Tests
These tests are performed when requested by
maintenance personnel. The truck must be in the
Test state for these tests to run.
• Maintenance Tests - The purpose of these tests
is to facilitate verification of system installation
and wiring, particularly the "digital" interfaces
(relays, contactors, etc).
• Self-Load Test - Self-load testing is a means by
which the truck's diesel engine can be checked
for rated horsepower output.
Periodic Tests
These automatic tests are run continuously during
the operation of the truck to verify certain equipment.
E02020 10/06
EVENT RESTRICTIONS
The PSC software will not override an event
restriction as long as the "limp home" mode is not
active. Transitions to restricted states will not be
allowed. If the system is in a state which becomes
restricted, it will transition down to the highest
unrestricted state. The order of the states, from
lowest to highest, is Startup/Shutdown, Rest, Test,
Ready, Retard, Propel.
Transitions to the Test state or lower states in
reaction to event restrictions will not be allowed until
the truck is not moving. The "limp home" mode is a
state which is entered when the truck has suffered a
failure and is not able to continue normal operation,
but is still capable of getting back to the maintenance
area, or at least out of the way of other trucks.
Event Restrictions associated with a given event are
listed in Table 1 earlier in this section.
EVENT LOGGING AND STORAGE
This software function is responsible for the
recording of event information. There are two basic
levels of event storage: event history buffer and data
packs. The event history buffer provides a minimum
set of information for a large number of events, while
data packs provide extensive information for a limited
number of events.
The following requirements apply to both data packs
and the event history buffer:
Electrical Propulsion System Components
• Fault information is maintained until overwritten;
it is not cleared out following a reset. This allows
the user to examine data associated with events
that have been reset, as long as there have not
been so many new events as to necessitate
reuse of the storage space.
• If a given event is active (logged and not reset),
logging of duplicate events (same event and sub-
ID numbers) will not be allowed. If the event is
reset and subsequently reoccurs, it may be
logged again. Likewise, if an event reoccurs with
a different sub-ID from the original occurrence,
the event may be logged again.
E2-33