Great Plains 3S-3000HDF Operator Manual v2 - Manual (Page 25)

Great Plains Manufacturing, Inc. Table of Contents Index Preparation and Setup 21
2014-02-11 Table of Contents Index 195-068M
Refer to Figure 12 on page 20 and Figure 13 at right
4.
Release locking discs on down-pressure valves.
Adjust knobs on pressure-control valves for
opener down pressure so gauges are at 2100 psi.
5. While watching gauges on drill, slowly turn knob on
bypass valve counterclockwise. Adjust bypass valve
just until needles on gauges begin to move down
from 2100 psi. Lock bypass valve at this setting.
(See also note below.)
6. Re-adjust pressure-control valves on drill to desired
opener down pressure as explained under See
“Opener Frame Down-Force” on page 50.
Note: The higher the bypass pressure, the greater the po-
tential for oil heating and premature tractor dam-
age. At the same time, for proper opener operation
the bypass valve must be set at least 300 psi above
the opener down-pressure setting when the tractor
is at one-half throttle. Therefore, you should set the
bypass valve as low as possible while staying at
least 300 psi above the opener down pressure set-
ting.
While 2100 psi is a good starting point for setting the
bypass valve, if you consistently operate the drill with low
opener down pressure you can set the bypass valve
below 2100 psi. If you consistently operate the drill with
very high opener down pressure, you may need a
bypass-valve setting above 2100 psi.
End of Preparation and Setup
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Figure 13
Down Pressure for Bypass
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