VRT Hydraulic Drive
– Manual Override
Page 72
05/06
Fig. V21 Thumb knob on VRT manifold.
Step 6.
Engage the hydraulics for the air
seeder at the tractor. Run the
hydraulics for the appropriate
time to simulate the 1/10
th
of a
hectare.
Example: If an implement had a 12.5metres
sowing width and was driven at a constant
9km/h ground speed, the sample run time
to calibrate the machine would be 32
seconds for a 1/10th of a hectare sample.
Step 7.
Weigh the sample and multiply
the sample weight by 10 to
determine the actual application
rate. Adjust the thumb knob
appropriately to increase or
decrease the next calibration
sample to obtain the desired
rate.
Example: After the 32 seconds the total
sample weighs 8.25kg. Therefore :
8.25 x 10 =82.5kg/ha application rate.
Step 8.
Repeat steps 6 and 7 until the
correct rate has been obtained
and checked. Lock the rear
thumb knob in position before
moving to the next bin.
Step 9.
To calibrate the next bin it will be
necessary to either remove the
material from the first bin, let the
material flow onto the ground or
remove a chain to prevent the
metering system from turning.
Step 10. Repeat the process as per the first
bin until all products have been
calibrated. Re-fit chains or refill
bins to prepare for operation. Re-
engage the fan’s flow control
valve.
The seeder should now be ready for
operation. When you engage the hydraulics
for the seeder at the tractor you will not only
start the fan but rotate the metering system.
It may be necessary to increase the fan
speed slightly to ensure the distribution
system is kept clear at all times.
Operational Limitations
The manual override system has limited
accuracy. It requires the operator to maintain
a constant ground speed. Variations in the
hydraulic oil temperature from the tractor can
create variations in metering speeds.
For example: as the tractor speeds up the
effective application rate will be reduced. If
the temperature of the oil varies from the
calibration temperature the change in
viscosity of the fluid can increase or
dec
rease the motor’s metering speed.
Therefore, it is important the operator
checks the rate of application is within an
acceptable range when using the Manual
override procedure. Check the bin levels are
lowering at the desired rate.
Note:
The manual override system is an emergency
system only. It will allow the operator to
complete a paddock or continue seeding
when there is no other option. The first
priority however, should be to determine the
actual problem with the monitor or pod
system. Refer to the trouble shooting section
in this manual or in the Farmscan Operator’s
Manual. Contact your local dealer for more
information. Remember to turn the thumb
knobs
off
when
returning
to
normal
operation.
