Control-Cut-Off valve (CCO valve)
The pump offers an optional control cut off valve integrated into the control. This valve will block charge
pressure to the control, allowing the servo springs to de-stroke both pumps regardless of the pump´s
primary control input. There is also a hydraulic logic port, X7, which can be used to control other machine
functions, such as spring applied pressure release brakes. The pressure at X7 is controlled by the control
cut off solenoid. The X7 port would remain plugged if not needed.
In the normal (de-energized) state of the solenoid charge flow is prevented from reaching the controls. At
the same time the control passages and the X7 logic port are connected and drained to the pump case.
The pump will remain in neutral, or return to neutral, independent of the control input signal. Return to
neutral time will be dependent on oil viscosity, pump speed, swashplate angle, and system pressure.
When the solenoid is energized, charge flow and pressure is allowed to reach the pump control. The X7
logic port will also be connected to charge pressure and flow.
The solenoid control is intended to be independent of the primary pump control making the control cut
off an override control feature. It is however recommended that the control logic of the CCO valve be
maintained such that the primary pump control signal is also disabled whenever the CCO valve is de-
energized. Other control logic conditions may also be considered.
MDC and EDC controls are available with a CCO valve.
The response time of the unit depends on the control type and the used control orifices.
The CCO-valve is available with 12 V or 24 V solenoid.
CCO-schematic (MDC shown)
Basic Information
H1 Axial Piston Pumps, Single and Tandem
Operation
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©
Danfoss | April 2017 11062168 | BC00000057en-US0602
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