Hydraulics; Axles - Goldacres MY17-19 Operator's Manual

Hydraulics

Electric over hydraulic spool valves allow the use
of a number of hydraulic functions on the sprayer
with only one set of tractor remotes. The hydraulic
functions are then controlled from an electric switch
box in the cabin. The valve block is located at the
rear of the sprayer above the boom valves.
Prairie Pro sprayers can be set up for use on closed
centre and open centre hydraulic systems. It is
important that you are familiar with the operating
system of your tractor prior to connecting your
sprayer.
A brief overview of the different hydraulic systems
follows below. Further information on your specific
system should be supplied by your dealer if required.
Open Centre Systems
Open centre systems have a constant flow of oil
from the tractor. Any flow not being used by the
hydraulic circuit will be bypassed through the system
and sent back to tank.

Axles

Prairie 4000, 5000 & 6500 litre sprayers can be fitted
with rigid axles and Air Bag suspension.
The air bag suspension consists of a 12 volt air
compressor, a ride height valve, 2 air bags, shock
absorbers, axle (used as an air reservoir) and hosing.
The 12 volt compressor is powered up when
the ignition is switched on. A fuse is fitted to the
ignition relay box to protect the compressor circuit.
The compressor, located in the right hand pod, has
a pressure cut out switch fitted to it which cuts
the power to the compressor when the reservoir
recommended pressure is achieved. When the
pressure in the reservoir drops below approximately
70 PSI, the compressor will start again. The pressure
cut out switch can be adjusted by turning the nut at
the end of the spring to apply more or less pressure
to the contact spring. The recommended maximum
pressure to run in the air bag system is 110 PSI.
Optimum pressure is 100 PSI. If the compressor
runs continually there may be an air leak present. All
hoses and fittings must be checked and repaired if
necessary.
The compressor draws its air through a paper
element filter mounted on the right hand side boom
rest. This filter element must be cleaned daily.
In dusty conditions this filter must be cleaned on a
more regular basis.
Prairie 1500-3000L Operator's Manual MY17-MY19 - REV 0
Closed Centre Systems - Pressure
Compensated
Tractors fitted with closed centre, pressure
compensated, hydraulic systems have a variable
displacement pump which only delivers flow at the
rate necessary to maintain a specified pressure.
Closed Centre Systems - Load
Sensing
A closed centre load sensing system is a variation
of the pressure compensated system and are
commonly designed to reduce hydraulic circuit heat
generation.
This system senses a change in flow, and or pressure,
and causes the pump to compensate by varying the
pump flow. In these circuits no oil is bypassed as only
the oil required is being sent to the valve.
Ground conditions, ground speeds and wind
conditions can all be factors in determining what
measures are necessary to supply clean air to the
compressor.
A gauge that displays air pressure is located on the
front of the machine.
Further information on air bag suspension and
axles can be found in the maintenance and
troubleshooting chapters.
Chapter 3 - General Information & Specs - 9