Response Time, Fnr 045/053; Non Feedback Proportional Electric Control (Nfpe) Options A8 (12 V)/B8 (24 V) - Danfoss H1 Technical Information

Technical Information
Control options

Non Feedback Proportional Electric Control (NFPE) options A8 (12 V)/B8 (24 V)

18
H1 Axial Piston Pump Size 045/053, Single
Charge pressure
Speed

Response time, FNR 045/053

Stroking direction 0.8 mm [0.03 in] Orifice
Neutral to full flow 1.8 s
Full flow to neutral 1.6 s
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.
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.
A serviceable 125 μm screen is located in the supply line immediately before the control porting spool.
P003 192
Pump displacement vs. input signal
100 %
NFPE control
Signal Current
mA(DC)
c a
b
"0"
a
100 %
11063344 • Rev HA • Mar 2014
= 20 bar
-1
= 1800 min (rpm)
1.3 mm [0.05 in] Orifice
0.9 s
0.8 s
b c
P003 187E
[290 psi]
No orifice
0.5 s
0.4 s