Great Plains NTA3007 Operator Manual - Manual (Page 108)

104 NTA907 or NTA3007 Table of Contents Index Great Plains Manufacturing, Inc.
166-371M Table of Contents Index 2012-07-02
Refer to Figure 102
4.
Release locking discs on transfer , centre and
wing down-pressure valves.
5. Adjust knobs on pressure-control valves , for
opener down pressure until gauges , are at
9.7 bar (1400 psi).
The recommended down-pressure ranges for drilling are:
Note: Rotate knob clockwise to increase pressure and
counter-clockwise to decrease pressure.
6. In some applications, pressure on centre section is
set slightly higher than the wings to account for
additional soil compaction due to tractor and drill
transport tires. Do not operate at pressures so high
that the wing gauge wheels loose traction, or are off
the ground, causing loss of seed depth control.
Setting the Bypass Valve
• LS Closed:
Tractors with load-sensing, Closed-Centre hydraulics
require the bypass valve
to protect the tractor
hydraulic system. Continue at See “Bypass with LS
or PFC Closed Systems” on page 105.
• PFC Closed:
Pressure Flow Compensating - same adjustment as
LS Closed. Continue at See “Bypass with LS or PFC
Closed Systems” on page 105.
• PC Closed:
Pressure Compensating - no bypass is required.
Release locking disc. Close bypass valve
for no oil
flow by turning knob clockwise completely. Tighten
locking disc. Always operate the drill with the bypass
valve locked closed.
• Open Centre (OC):
The NTA907 and NTA3007 drills are not presently
compatible with tractors that have Open-Centre
hydraulics.
If you are unsure what type of hydraulic system is on
your tractor, contact your tractor manufacturer.
Centre 4.8 to 14.5 bar (700 to 2100 psi)
Wings 5.5 to 15.2 bar (800 to 2200 psi)
Figure 102
Down-Pressure Adjustment
29422
1
2
w
c
t
T
C
W
B
T C
W
C W
c w
c
w
B
B