Great Plains 3N-4025P Operator Manual - Manual (Page 34)

3N-4010P, 3N-4015P, 3N-4020P and
3N-4025P
196-286M 4/23/2010
32
HD 10 Series Hydraulic Depth Control
Refer to Figure 21
The field-lift cylinders are equipped with a hydrau-
lic valve that regulates opener frame height.
Loosen the bolt on the side of the depth stop and
slide the depth stop up to raise the opener frame
or down to lower the opener frame. Retighten bolt
after setting the depth stop.
Make depth adjustments with the implement
slightly raised. After adjusting the valve, raise and
lower the implement several times and recheck
frame height.
The depth stop regulates the height of all opener
frames. If the ends of either box run higher or low-
er than the center, the field-lift system may be out
of phase or have air in it, or the frame sections
may not be level. Refer to “Rephasing Lift Sys-
tem,” page 24, “Bleeding Lift Hydraulics,” page 17,
or “Leveling Frame Side-to-Side,” page 19.
Refer to Figure 22
For no-till conditions, the opener frame height
should be set so the bottom of the opener frame is
26” above the ground. This allows the opener par-
allel arms to run parallel to the ground giving the
opener the maximum upward or downward
flotation.
In loose or conventional planting conditions, set
the frame height above 26” to help keep the no-till
spring forces from buring the openers.
NOTE: Setting the frame above the 26” limits
the opener downward flotation.
NOTE: Running with the frame below 26” lim-
its opener upward flotation and could cause
opener damage especially at center of the
drill.
Depth Stop
Bolt
Raise Coulters
Lower Coulters
20274
Figure 21
Depth Control Adjustment
Note: It is important that all of the tires remain
in contact with the ground to maintain level-
ness of machine from front to rear. Setting the
depth control too deep combined with high
opener spring force can cause the drill to tip
forward when planting, which may cause plug-
ging.
Running with the front tires floating or skimming on
the ground will cause uneven coulter depth and
may cause uneven seed depth.
Figure 22
Frame Height
Figure 21
Depth Control Adjustment