Great Plains NP4000B Operator Manual - Manual (Page 53)

Great Plains Manufacturing, Inc. Table of Contents Index Operating Instructions 49
2014-05-14 Table of Contents Index 417-199M
Fold/Lift Circuit
The fold and lift cylinders share a single hydraulic circuit.
Solenoid valves (controlled by a switch box), one or more
passive valves, and mechanical locks control hydraulic
sequencing.
This system design provides a partial fold, as a single
self-limiting hydraulic operation, during field lift, providing
extra wing clearance in field turns.
If the hydraulic harness is not connected at the hitch, or
the switch box is off, or power is off, most valves default
to an Open state.
FOLD / FIELD Switch
Refer to Figure 21 (depicting the switch in PARK)
This switch is mounted in the tractor cab (page 176), and
connected to the applicator at the hitch. It controls
several solenoid valves on the applicator. It has three
toggle positions and two indicator lamps.
Note: The switch is powered by the tractor. An illuminated
lamp indicates power sent to the harness. The
harness must be connected at the hitch for the
function to be effected.
Switch Positions
PARK All solenoid valves are powered off and are
spring-loaded to flow-open positions.
Use this position only for parking, to save
tractor battery power. With the switch in PARK,
any hydraulic flow to the fold/lift circuit may
have undesired results.
FOLD
UNFOLD Full fold and unfold sequence is controlled.
Down-pressure is disabled.
During unfold, the inner wings unfold before
the outer wings. During fold, the outer wings
fold before the inner wings. Fold range from
fully folded to wings level (excepting
down-pressure) is available.
FIELD Outer wings locked.
Inner wing fold restricted to “gull wing”.
Down-pressure available.
Use this position in the field. It engages the
down-pressure circuit for weight transfer.
It provides a partial fold for extra wing
clearance in field turns.
Figure 21
FOLD / FIELD Switch
34918
Machine Damage Risks:
Lift/lower (except field lift) and fold/unfold operations are
possible with the hydraulic harness off, but care must be
exercised. It is possible to lower below level, which can result
in row unit ground strikes and dragging.