Manual Override (MOR)
All controls are available with a manual override functionality, either as a standard or as an option for
temporary actuation of the control to aid in diagnostics.
Control with manual override
P003 204
MOR schematic (EDC control shown)
P
T
F00B
M14
C2
C1
F00A
Feedback from swash plate.
The MOR plunger has a 4 mm diameter and must be manually depressed to be engaged. Depressing the
plunger mechanically moves the control spool which allows the pump to go on stroke. The MOR should
be engaged anticipating a full stroke response from the pump.
An o-ring seal is used to seal the MOR plunger where initial actuation of the function will require a force
of 45 N to engage the plunger. Additional actuation typically require less force to engage the MOR
plunger.
Proportional control of the pump using the MOR should not be expected.
W
Warning
Unintended MOR operation will cause the pump to go into stroke;
example:
vehicle lifted off the ground.
The vehicle or device must always be in a safe condition when using the MOR function.
Refer to control flow table for the relationship of solenoid to direction of flow.
Manual Displacement Control (MDC)
A Manual proportional Displacement Control (MDC) consists of a handle on top of a rotary input shaft.
The shaft provides an eccentric connection to a feedback link. This link is connected on its one end with a
porting spool. On its other end the link is connected the pumps swashplate.
This design provides a travel feedback without spring. When turning the shaft the spool moves thus
providing hydraulic pressure to either side of a double acting servo piston of the pump.
Differential pressure across the servo piston rotates the swash plate, changing the pump’s displacement.
Simultaneously the swashplate movement is fed back to the control spool providing proportionality
between shaft rotation on the control and swash-plate rotation. The MDC changes the pump
displacement between no flow and full flow into opposite directions.
Service Manual
H1P 069—H1P 280 Axial Piston Single Pumps
Operation
16 |
©
Danfoss | January 2021
AX152886482551en-000601