Initial down-pressure, Set or calibrate bypass, Set bypass for pc closed – Great Plains V-300F Operator Manual User Manual
Page 26: Set bypass for ls closed/pfc, Set down pressure
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V300 & V300F
Great Plains Manufacturing, Inc.
148-057M-A
11/15/2007
Initial Down-Pressure
If the down-pressure valve has been previously set for
field operations, leave it as is.
If this is the first use of the drill, calibrate the bypass
valve and set the initial pressure to 800 psi.
Set or Calibrate Bypass
Refer to “Lift/Lower Operations” on page 35 to know
what to expect the drill to do as hydraulics are cycled.
Set Bypass for PC Closed
Tractors with Pressure Compensating Closed Center
Hydraulics:
• Release locking disk
. Close bypass valve
for no
oil flow by turning knob
on valve clockwise com-
pletely. Tighten locking disk
. Always operate the drill
with the bypass valve closed.
Set Bypass for LS Closed/PFC
Tractors with Load Sensing Closed Center or Pressure
Flow Compensating Hydraulic Systems:
1.
Release locking disk
. Close bypass valve
for no
oil flow by turning knob
on valve clockwise com-
pletely. Tighten locking disk
2.
With tractor at half throttle, adjust flow-control valve
on tractor so openers raise and lower at a reason-
able speed. Keep tractor at one-half throttle for
remaining steps.
3.
Engage tractor hydraulics and lower openers. Lock
hydraulic lever on tractor for continuous operation.
4.
Release locking disk
on pressure control valve
.
Adjust pressure-control valve knob
for opener
down pressure so gauge
5.
Release locking disk
on bypass valve
watching gauge
, slowly turn knob
on bypass
valve
counterclockwise. Adjust bypass valve
just until needle on gauge
begins to move down
from 1800 psi. Use locking disk
to lock bypass
valve at this setting. (See also note at right.)
Set Down Pressure
Adjust pressure-control valve
to desired opener down
pressure per “Hydraulic Down Pressure” on page 36.
Tighten locking disk
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.
IMPORTANT !
The standard model V300 and V300F require a trac-
tor with “Closed Center” hydraulics. If the intended
tractor has “Open Center” hydraulics, the drill requires
a kit to convert it to open center operation. Have your
Great Plains dealer contact the factory.
IMPORTANT !
Failure to use the bypass valve on load-sensing trac-
tors may cause major tractor damage.
Note: Faster opener raise/lower increases potential for oil
over-heating, excess wear and tractor damage.
The higher the bypass pressure, the greater the potential
for oil over-heating and 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.
Figure 17
Initial Down-Pressure Setting
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