Open And Closed Centre Hydraulics - Hardi COMMANDER DELTA FORCE Instruction Book

4 - Sprayer Setup

Open and Closed Centre Hydraulics

This hydraulic block is necessary, if the tractor uses open centre
hydraulics and/or load sensing (LS).
The valves (pos.1 and 2) is factory set for open centre hydraulics, but if
closed centre hydraulics is used (also in combination with load sensing),
screw in the valves clockwise.
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WARNING! Always be sure to fully open or close the selection
valves for open/closed centre hydraulics.
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NOTE! The hydraulic block is accessed from below the sprayer
chassis.
Certain tractor models are able to use Load Sensing without connecting
an external sensing line. But if optimal sensing control pressure cannot
be obtained, an external sensing line needs to be connected to the
tractor.
Connection to Tractor
If Load Sensing (LS) is to be used, connect a hydraulic hose from the
tractor's LS port to the O-LS port (D) on this hydraulic block.
Connection size for port D is G1/4".
The restrictors inside the hydraulic block have different orifices
depending on the oil flow returned to the tractor's oil pump.
A. Orifice is ø0.8 mm (default setting).
B. Orifice is ø1.2 mm
C. Orifice is ø1.6 mm
• Check the hydraulic flow by activating a hydraulic lever in the
tractor. If the reaction time for the hydraulic function is relatively
short, continue your work with this restrictor installed.
• If the reaction time seems too long before the hydraulic function is
enabled, switch the plug (E) in port (A) with the plug (F) in port (B)
to allow more oil flow to pass through.
• If the reaction time is still too long, switch the plug (E) in port (B)
with the plug (F) in port (C).
• Always mount the plug (E) in the port used, and mount the other
plugs (F) in the ports not used.
• Ask your HARDI dealer for correct setup if in doubt.
Combinations of settings for hydraulic block:
Application Valve 1
Open centre Out
Closed centre In
Load sensing (LS) In
*If the tractor requires pressure relief, contact your tractor dealer for further advice.
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WARNING! It is essential that connectors on the sensing line are kept totally clean, so that impurities do not enter the
pump. Impurities may cause damage to vital pump parts.
Before operating the hydraulics, the valve should be set according to the specific tractor model. If you are unsure of
the type of hydraulic system in your tractor, please contact your tractor dealer.
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NOTE! A spare part kit for connecting the hydraulic block to the tractor - ask for HARDI item no. 74193800.
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Valve 2 Port A, B or C
Out No change
In No change
Out* Change if needed