Air and seeding system overview – Great Plains 1625AHL Operator Manual User Manual
Page 53
Great Plains Manufacturing, Inc.
Operating Instructions
49
2014-04-21
411-020M
Air and Seeding System Overview
Refer to Figure 35, on page 48, and Figure 36.
Callout numbers
through
throughout this manual and refer to air system and seed
metering components.
The hydraulic fan
supplies air exclusively for meter
operation. Fan rpm is operator-adjusted (page 53),
normally via the tractor circuit’s hydraulic flow control.
On dry fertilizer models, the fan first supplies a
manifold
that divides airflow for meter pressurization
and fertilizer delivery. A sensor port
measures raw
fan pressure, reported on a third Magnehelic
®
gauge
located inboard of the right wing Magnehelic
®
gauge
. A manually-adjusted butterfly valve
is
provided at the fan outlet. See page 52 for adjustment.
Meter pressurization air
is divided for each wing at a
splitter
, which has no adjustments.
An inlet
routes the meter pressurization air into the
wing frames. A butterfly valve
at each inlet is
normally fully open, but is available for balancing
pressures (see page 54).
The wing frames act as manifolds and have exit
ports
for all possible row spacings. Unused ports are
plugged. Active ports have an elbow
which supplies
air to a row unit Air-Pro
®
meter
.
Seed is delivered from the seed hopper
by gravity to
the inlet
of the Air-Pro
®
seed meter.
A manually adjusted inlet shutter
controls the size of
the seed pool
at the base of the meter. The shutter
also minimizes air loss back up the seed inlet tube, and
is also used during row shut off. See Seed Rate Manual
for initial settings. See page 79 for shutter adjustments.
At the meter, pressurization air exits the meter through
the seed pockets
of the disk, and holds seed in the
pockets until released above the seed tube
.
In the seed tube, the seed sensor
detects passage
of seeds. Medium size and large seeds are counted
individually. With smaller seeds, most are detected,
allowing the monitor to detect stoppages.
Several rows have a pressure sensor port
for the
meter pressurization system. A line
from each of
these rows is connected to a chamber
to average the
pressures.
The averaged pressure is reported by a Magnehelic
®
gauge
visible to the tractor operator. See page 53 for
use of the gauge in making fan adjustments.
A sensor
in each seed tube reports seed passage to
the seed monitor. Larger seeds are counted individually.
For smaller seeds, the system acts as a blockage
monitor.
Note: Use of the special blank disk (page 83), and closing
the seed inlet shutter (page 79), are particularly
important when a sensor row is shut off.
Note: On any row, running a normal disk with no seed, or
with an open empty inlet, unbalances the air
system. Doing either at a sensor row causes the
gauge to mis-report as well.
Note: Do not operate in the ground with the fan shut off, or
with insufficient manifold pressure. The meters will
completely fill with seed. Meter clean-out may be
required to resume normal operation.
Figure 36
Air-Pro
®
Meter, Disk Side
31040
A24
A30
A16
A27
A25
A26
A28
A29
A11
A11
A13
A14
A15
A16
A17
A18
A19
A20
A21
A22
A23
A24
A25
A26
A27
A28
A29
A30
A31
A32
A29