Great Plains NTA3007HD Operator Manual - Manual (Page 87)

Adjustments 83
04/04/2011 166-207M
Fan Speed Adjustments
The function of the airbox at the seed meter is to mix
seed with turbulent air from the hydraulic fan, which then
exits through primary hoses at each meter, to the towers,
and via secondary hoses to the rows.
Fan Operation
Refer to Figure 88
All three (3) fan hydraulic lines must be properly con-
nected. “Hydraulic Hose Hookup” on page 19.
Use tractor remote hydraulic valve flow control to set fan
speed. Start with a very low speed and verify that fan
impeller is spinning in the correct direction by observing
fan rpm on the seed monitor.
Note: If the fan cannot reach 3000 rpm, one or more hos-
es may be mis-connected. Air moves toward the air
box in either direction of fan rotation, but reverse
spinning airflow is too low to operate the air box.
Start with flow on low setting. 30-45 liters/min (8-12 gpm)
is average flow.
Run fan for at least 15 minutes before seeding. Hydraulic
fluid must be warm before fan and wing down pressure
will operate properly.
1. Check bin-lid and meter-box seals for air leaks.
Adjust the latch or replace the seals to prevent leak-
age.
Note: It only takes a very small air leak to cause large
variations in the seeding rate and pattern.
2. Watch the seed monitor and adjust fan speed by
increasing or decreasing hydraulic flow from the trac-
tor. Use the following guidelines and the fan speed
chart at right to properly adjust fan speed.
The monitor has a level sensor below the hopper or seed
box to warn when seed box is empty. Approximately
530 liters (15bu) of seed remains in the system when the
sensor first indicates box empty.
• Higher fan speeds improve seed distribution, but
high fan speeds also increase the chance of seed
damage and bounce.
• At first, adjust fan speed to the high end of the
range suggested in the chart at right. Watch for
excessive seed cracking and seed bounce from
the furrow, then reduce fan speed if necessary.
• Follow the chart at right as a guide. Actual fan
speeds vary with implement width, row spacing,
seeding rates, seed weights and seed size.
Increase fan speed for heavier seeding rates or
seed. Reduce fan speed for lighter seeding rates
and seed more prone to cracking.
Null4:
Figure 88
Fan Hydraulics
29464
Recommended Fan Speeds
Seeds Fan RPM
Sunflowers 2250 - 3000
Wheat 3250 - 4000
Soybeans 2750 - 3500
Milo 3250 - 4000