Electrical Displacement Control (EDC)
The Electrical Displacement Control (EDC) consists of a pair of proportional solenoids on each side of a
three-position, four-way porting spool. The proportional solenoid applies a force input to the spool,
which ports hydraulic pressure to either side of a double acting servo piston.
Differential pressure across the servo piston rotates the swashplate, changing the pump‘s displacement
from full displacement in one direction to full displacement in the opposite direction.
Under some circumstances, such as contamination, the control spool could stick and cause the pump to
stay at some displacement. A serviceable 125 μm screen is located in the supply line immediately before
the control porting spool.
Electrical Displacement Control, with hydraulic schematic
P003 191
Feedback from
Swash plate
P
T
F00B
M14
C1
C2
F00A
P003 478E
Pump displacement vs. control current
P003 479E
"0"
-b
-a
b
a
100 %
100 %
Displac
emen
t
Current mA
EDC Control Signal Requirements
Control minimum current to stroke pump
Voltage
a
*
b
Pin connections
12 V
640 mA
1640 mA
any order
24 V
330 mA
820 mA
*
Factory test current, for vehicle movement or application actuation expect higher or lower value.
Technical Information
H1 Axial Piston Single Pumps, Size 045/053
Control Options
©
Danfoss | May 2017
11063344 | BC00000059en-US1001 | 17
