Electrical Displacement Control (EDC)
An EDC is a displacement (flow) control. Pump swash plate position is proportional to the input
command and therefore vehicle or load speed (excluding influence of efficiency), is dependent only on
the prime mover speed or motor displacement.
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 swash plate, changing the pump‘s displacement from full displacement in
one direction to full displacement in the opposite direction.
A serviceable 125 μm screen is located in the supply line immediately before the control porting spool.
Under some circumstances, such as contamination, the control spool could stick and cause the pump to
stay at some displacement.
Electrical Displacement Control
P003 191
EDC schematic, feedback from swash plate
Feedback from
Swash plate
P
T
F00B
M14
C1
C2
F00A
P003 478E
Service Manual
H1P 045/053/060/068 Axial Piston Single Pumps
Operation
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Danfoss | June 2020
AX152886481964en-000405 | 15