A-Solution Tank
B-Solution Manifold

C-Suction Strainer
D-Centrifugal Pump
E-Filter
F-Pressure Manifold
G-Eductor
H-Boom Section Shut-off Valves

I-Spray Nozzles
J-Solution Flowmeter
K-Proportional Valve
L-Hydraulic Motor
M-Pressure Transducer
N-Check Valves
O-Rinse Tank

P-Agitation Solenoid Valve
Q-Wheel Speed Sensor
R-High/Low Flow Valve
S-Radar
T-CCU/SRC
U-SPRAYSTAR™ Display
V-Agitation Adjust Valve

The solution spray system consists of a tank, suction manifold, suction strainer, centrifugal pump, high/low

SPRAYSTAR is a trademark of Deere & Company.

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Solution tank is made from polyethylene or stainless steel and has a capacity of 2839 L (750 gal). An access/fill cap is located at the top of the tank. At the side of the machine is a clear tube and graduated scale that indicates solution level in liters and gallons. Located at the bottom of the tank is the shut-off/solution outlet valve.

The suction manifold has three functions:

• The pump pulls solution from the tank to pressurize the spray system.
• The pump pulls on fresh water through the quick-fill attachment to fill the tank.
• The pump pulls clean water from the fresh water tank to flush the system.

The suction strainer located on the suction manifold is constructed of a noncorrosive materiel that should be cleaned as required. The solution pump is a centrifugal type that is driven by a hydraulic motor. Engagement and disengagement of the pump is controlled by a switch located on the hydro lever. Any air trapped in the pump is allowed to escape through a bleed-off line. This helps prevent pump cavitation.

A filter is located on the back of the boom in line before the flowmeter. The filter removes sediment before it reaches flowmeter and boom valves.

A high/low flow valve is located on the boom to the left of the flowmeter. It is used to improve the control of the spray rate control system when smaller nozzles are used. The valve is set in open position for medium to high flow rates and in closed position for a flow rate of 100 Lpm (26 gpm) or less.

Agitation jets are in two locations on the bottom of the tank. The jet creates a vigorous fan type agitation throughout the tank to keep chemicals, such as wettable powders, in suspension. A valve is located under fuel tank that can be adjusted to attain the desired agitation effect. A valve controlled by a switch on the console can be used to turn the agitation on and off.

Pressure manifold does one of three things:

• Directs fill water to the eductor manifold.
• Directs clean water to the tank rinse system.
• Directs water or solution directly to the tank.

The eductor manifold directs fill water through a venturi at the bottom of the hopper to create a vacuum to pull the chemical into the water stream. The manifold directs water to the hopper rinse and the jug rinse through two valves.

Spray control valves are motorized ball valves that cycle completely open or completely closed. The valves are operated by switches on the operator's side console.

The spray nozzles, located on the center frame and boom, meter, atomize and dispense the solution into specific patterns. Solution flow is metered by the size of the orifice in the nozzle tip. Within limits, solution flow through a nozzle can be increased or decreased by adjusting system pressure.

Most nozzles are designed for optimum performance at specific pressures. However, the range of adjustment is relatively narrow. Line pressures too high or too low will affect atomizing the solution and create variations in the spray pattern. The solution atomizes when the liquid is forced through the orifice in the nozzle. The shape of the spray pattern is determined by the shape of the orifice.

When the pump is activated, solution is drawn from the solution tank, through the suction manifold and suction filter. The pump pushes the solution to the filter and on to the spray control valves, then to the pressure manifold for agitation.

When the spray control valves are open, the solution flows to the nozzles, where it is atomized and sprayed.

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The flowmeter on the boom sends an electronic signal to the CCU/SRC, which compares that signal to the operator-programmed application rate. If there is a difference in the signal from the flowmeter and the programmed rate, the compensator in the proportional valve assembly will open or close as needed until the system is stabilized.

When the compensator opens, more hydraulic oil is sent to the hydraulic motor, causing the solution pump to increase its flow. When the compensator closes, less hydraulic oil is sent to the hydraulic motor, causing the solution pump to decrease its flow.

The Spray Rate Controller (SRC) provides the ability to maintain application within a range of application rates while changing speeds. Application rate consistency depends on a number of things such as nozzle tip size, application rate, and rate of speed change. The SRC provides quick response, but some differences in application rates can be observed if the operator makes rapid speed changes or operates at the extremes of the solution pressure range.

Principle parts of the SRC system are a speed sensor (either a wheel speed sensor on left front wheel motor or a radar speed sensor at front of machine), the spray rate controller, a variable speed solution pump, a flowmeter, and a solution pressure sensor. The speed sensor and flowmeter provide speed and flow rate information to the spray rate controller. The spray rate controller provides target (programmed by the operator) application rates by analyzing speed and flow data, and then making appropriate adjustments to the variable solution pump.

The spray rate controller is part of the Chassis Computer Unit/Spray Rate Control Unit (CCU/SRC) located under the floor plate inside the cab. The spray rate controller has an internal warning system that alerts the operator if the actual flow rate varies from

The solution pressure required for a given application rate is determined by speed and nozzle tip size. Before attempting to use the SRC, refer to a nozzle tip calculator or nozzle tip selection charts, and make sure the spray boom is equipped with spray tip nozzles that will provide desired application rates at desired pressures and speeds. Ground speed variation is limited by the operating pressure range of the nozzle tips.

The master "on/off" button located on the hydro lever is an integral part of the SRC system. When "off" is pushed, electrical power closes the boom valves and the variable solution pump slows to maintain spray-off pressure (as set by the operator).

Solution may continue to spray from the boom for a short period of time after master "off" is pushed. This is due to pressure remaining in the line. The time interval that spray will continue flowing depends upon pressure in the spray line, boom hose lengths and routings, nozzle tip size, and use of nozzle check valves. In order to compensate for the boom shut-off lag time, master "off" should be pressed prior to reaching the turnrow.

Once master "on" has been pressed, if the machine is moving slowly or is not moving, the variable solution pump will maintain the minimum solution pressure as set by the operator. This may result in an application rate that is higher than the target rate (programmed by the operator). Likewise, if the machine is moving too fast, the variable solution pump will maintain the maximum solution pressure. This may result in an application rate that is lower than the target rate.

SPRAYSTAR is a trademark of Deere & Company.

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