Great Plains V300 Assembly Instructions - Manual (Page 19)

Great Plains Mfg., Inc.
Installation Instructions 19
11/08/2006 148-771M
Operation
Closed Center Field Operation
The openers are mounted on floating opener frames
which follow the contour of the ground while maintaining
constant opener down pressure.
1. Lower the opener frames by pushing FORWARD on
the tractor remote hydraulic lever. The remote lever
must be LOCKED OPEN in this position to provide
constant pressure/flow to the openers.
John Deere tractors with Sound-Gard ® Body:
Use lever lock clip, John Deere part number
R52667, to lock lever forward. See your tractor
dealer for clip purchase and installation.
John Deere 7000 Series tractors: Rotate valve
detent selector to motor position to lock lever in for-
ward position.
John Deere 8000 Series tractors: Set timer to con-
tinuous. Push lever forward until detent clicks.
Case-IH Magnum tractors: Lock lever forward in
detent position. You may need to turn up detent
pressure to its maximum setting. Do not tie hydraulic
lever past detent position with a strap. See your trac-
tor dealer for hydraulic-system details.
Other tractors: Lock lever forward in detent posi-
tion. You may need to turn up detent pressure to
maximum or use a mechanical detent holder to hold
lever forward. See your tractor dealer for proper
means of providing constant flow to openers.
Refer to Figure 27
2. With the tractor hydraulic lever locked forward,
release the lock disk
➀
, turn the knob on the pres-
sure control valve (44) as shown in Figure 27. Watch
the pressure gauge (43) and dial in the desired pres-
sure on the openers. Clockwise increases the pres-
sure and counterclockwise decreases pressure.
Once the pressure is set, lock the knob with the lock
disk
➀
.
Note: Refer to “Post-Installation Lift Cycle” on page 17
to know what to expect the drill to do as hydraulics
are cycled.
The recommended pressure range for drilling is between
200 psi and 1400 psi. Setting the opener down pressure
above 1600 psi will raise the drive wheels off the ground
when the seed box is empty causing skips and poor seed
metering. See the following table for the relationship
between psi and down force.
The following down-forces are per-opener, with no extra
weight on the hangers (at the lower down-force values).
Higher down-force values may require weights on the
hangers. Consult the Operator’s Manual for further infor-
mation.
Figure 27
Closed Center Valves
25185
43
➀
44
Adjustment Valve Table
System
PSI
Down Force
Pounds Kg
200 62 137
300 77 170
400 84 185
500 96 212
600 110 243
700 123 272
800 139 306
900 155 341
1000 173 380
1100 194 427
1200 217 479
1300 249 548
1400 268 591