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3. If you see a > 2ohms reading on any channel from the test in A above, inspect the wires and cable
for that channel for obvious breaks; field repair if possible. If none are found or are repairable,
replacement of wiring harness may be required.
Note: intermittent electrical problems are difficult to diagnose. Flex wiring and connectors while checking
continuity.
B. Testing Electrode continuity
1. It is unlikely that a continuity problem could exist between the terminal bolt and the soil engaging
electrodes on electrodes 2 and 3, as the terminal bolt is tapped directly into the shank member for
that electrode. If a non-cable related continuity issue arises, it most likely would be found on the
rotating electrodes—electrode #1 front turbo coulter or electrode #4 rear closing wheels. Because
electrical signals cannot be sent consistently through a bearing, Veris has designed a more reliable
path for the EC signal to travel. A special hub with a spring plunger presses against the spindle of
the coulter, serving as a commutator. Shown below is a cut-away view of the hubcap and plunger
assembly. When ohm readings jump during blade rotation, it is due to the greased rollers on the
bearing making intermittent and inconsistent contact.
2. Place ohmmeter lead on terminal wire bolt and other lead on rotating electrode. Rotate electrode ¼
turn. If readings are consistently above 2 ohms, check for excessive corrosion at the coulter blade
mounting bolts, or the terminal located near the coulter pivot. Make sure that high ohm readings are
not due to poor contact between blade and ohmmeter lead. Re-test holding lead firmly against edge
of blade, removing rust or paint if necessary.
3. If ohms jump over 2 ohms when the blade is rotated, and you were careful to maintain good contact
between the lead and the blade, the problem is likely inside the hub. See Maintenance and Service
procedure #5: Spring Plunger adjustment and replacement on adjusting and replacing spring
plungers.
hubcap
commutator
coulter spindle
Figure 4.3
6-6
Pub# OM22-iScan EC-OM
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