Analog Input Checks - Komatsu 830E Shop Manual

3.2 Analog Input Checks

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The two digit diagnostic display panel should have a 00 event code to indicate that all previous
event codes have been cleared. If not, press reset button to clear codes.
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For each of the analog inputs listed, perform the test procedure specified, and verify the results
on the MONITOR ANALOG INPUT CHANNELS screen. Be sure to restore any switch settings
and wiring changes to their original condition before moving on to check the next analog input.
Reset as required to clear event data after each test.
1. GROUND FAULT CHECK: . . . . . . . . . . . . . . . . . . . ground fault = 0.0 ma
(Screen value ma = 48.1 x analog card input volts).
a. Jumper 24 vdc, circuit 71 to GFIP terminal "A" to simulate a "Low Ground" fault.
Read approximately 135 ma on PTU screen.
Event code 01 should appear on the 2 digit display.
The Electrical System Fault light should turn on.
b. Remove jumper attached to GFIP terminal "A".
PTU screen should read approximately 0 ma.
c. Press Override switch and reset button on 2 digit display to clear event code to 00.
d. Jumper 24 vdc, circuit 71 to GFIP terminal "D" to simulate a "High Ground" fault.
Read approximately 535 ma on PTU screen.
Event code 02 should appear on the 2 digit display.
The Electrical System Fault light should turn on.
e. Remove jumper attached to GFIP terminal "D".
PTU screen should read approximately 0 ma.
f. Press Override switch and reset button on 2 digit display to clear event code to 00.
g. To check GFIP, disconnect circuit 79H at terminal "A". Attach an ohmmeter to terminals "A"
and "E".
Read 100K ±1K ohms.
h. Reinstall wire 79H at terminal "A".
i. To check GRR panel, remove protective grille and disconnect the following wires routed to
the control cabinet: 7J1 from terminal "C" and wire 79H from terminal "B".
j. Use an ohmmeter to measure the following values.
Terminal "A" to "B": 200 ±20 ohms.
Terminal "B" to "C": 800 ±80 ohms.
Terminal "A" to "C": 1000 ±100 ohms.
k. Reinstall 7J1 and 79H wires removed in step i. Install GRR protective grill.
E03012 2/02 Statex III Electrical Checkout Procedure E3-25