Non Feedback Proportional Electric Control (Nfpe) - Danfoss H1P 045 Technical Information

Technical Information
H1 Axial Piston Single Pumps, Size 045/053
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Non Feedback Proportional Electric Control (NFPE)

26 | © Danfoss | May 2017
The Non Feedback Proportional Electric (NFPE) control is an electrical automotive control in which an
electrical input signal activates one of two proportional solenoids that port charge pressure to either side
of the pump servo cylinder. The NFPE control has no mechanical feedback mechanism.
A serviceable 170 μm screen is located in the supply line immediately before the control porting spool.
Non Feedback Proportional Electric Control
P003 192
NFPE schematic
M14
C1 C2
F00B F00A T
The pump displacement is proportional to the solenoid signal current, but it also depends upon pump
input speed and system pressure. This characteristic also provides a power limiting function by reducing
the pump swashplate angle as system pressure increases. A typical response characteristic is shown in
the accompanying graph. Under some circumstances, such as contamination, the control spool could
stick and cause the pump to stay at some displacement.
P
P003 188
11063344 | BC00000059en-US1001