Open Centre Hydraulics - Hardi COMMANDER DELTA FORCE Instruction Book

Open Centre Hydraulics

The open centre hydraulics block is necessary, if the tractor uses open
centre hydraulics and/or load sensing.
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 valve (clockwise).
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 (pos. 3) to
the tractor.
A spare part kit is available (HARDI item no. 74193800). From this kit,
install the restrictor with the smallest centre hole:
• check your 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, replace the restrictor with the bigger model from the kit to allow more oil flow to pass through.Ask your
HARDI dealer for correct setup and correct connection, if in doubt.WARNING! 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.
Combinations of settings for flow element and circuit value:
Valve no.
Open centre
Closed centre
Load sensing (LS)
*If the tractor requires pressure relief, contact your tractor dealer for further advice.
WARNING! Always be sure to fully open or close the open/closed centre selection valve. Failure to do so may cause damage
to vital pump parts.WARNING! It is essential that connectors on sensing line are kept totally clean. Failure to do so can result
in impurities entering the pump and causing damage to vital pump parts.
1 2
Out Out
In In
In Out*
3 (O-LS port)
Not connected
Not connected
Connected
4 - Sprayer Setup
73