Great Plains 3S-5000HDF Operator Manual - Manual (Page 31)

Great Plains Manufacturing, Inc. Table of Contents Index Operating Instructions 27
2012-08-14 Table of Contents Index 195-325M
Refer to Figure 20
4.
Adjust pressure-control valves on drill for opener
down pressure so gauges are at 1800 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 1800 psi. Lock bypass valve at this setting.
(See also note below.)
6. Adjust pressure-control valves on drill to desired
opener down pressure as explained under “To run
the drill with constant opener down pressure
requires an Active Hydraulic System. An Active
Hydraulic System requires a tractor with
closed-center hydraulics or pressure/flow
compensated hydraulics powered by a variable
displacement hydraulic pump. (If you are not
familiar with your tractor’s hydraulics, consult
your tractor dealer.)” on page 47.
Note: The higher the bypass pressure, the greater the
potential for oil heating and premature tractor
damage. 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 setting.
While 1800 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 1800 psi. If you consistently operate the drill with
very high opener down pressure, you may need a
bypass-valve setting above 1800 psi.
Figure 20
Opener Down Pressure Control
Valves
34293
Adjustment
Knob
Lock Disk