5. Rotate the neutral adjusting screw clockwise half the distance between the wrench positions noted
above. The gauges should read the same pressure, indicating that the control is in its neutral position.
6. Hold the neutral adjusting screw stationary and tighten the locknut (D060). Torque to 12 N•m [9
lbf•ft]. Do not over torque the nut.
7. When the neutral position is set, stop the prime mover, remove the gauges, and install the gauge
port plugs. Reconnect the external control input.
A small pressure differential of 1.5 bar [22 psi] or less is acceptable. Zero differential is usually not
possible.
Neutral Adjustment (EDC) (bottom view)
Solenoid shaft
Feedback pin
Adjusting
screw
(cam)
P106 046E
Maximum
adjustment
less than 120°
Control spool
Illustration shows how cam on adjusting pin rotates to adjust for neutral position after pump is re-
installed.
Mechanical Neutral Adjustment
Mechanical neutral is set with the pump running at 1800 min¯¹ (rpm). To set neutral, you must stroke the
pump in each direction. You can do this with a small movement of the eccentric screw on EDC controls,
however non-feedback controls (NFPE/FNR/FDC) lack this mechanism. To stroke a pump with non-
feedback control, you must provide a 100 Hz PWM signal to the control solenoids. Refer to the
H1 Pumps
Technical Information Manual
11009999 for signal specifications. If you perform this adjustment with the
pump installed in a vehicle or machine, safely elevate the wheels or disconnect the mechanism to allow
safe operation during adjustment.
This procedure details setting neutral for the pump. Alternate M4/M5 and MA/MB to zero out forward
and reverse directions of the unit Refer to the drawing on the next page to identify all ports. The control
solenoids C1 and C2 are marked on the control.
While performing this adjustment, you will monitor the following pressures.
•
Servo pressure at M4 and M5
•
System pressure at MA and MB
•
Pressure differential between M4 and M5 (optional)
•
Pressure differential between A and B (optional)
Refer to
Pressure measurement
and the illustration on the next page for gauge port locations and
information.
Service Manual
H1 Pumps 069/078, 089/100, 115/130, 147/165, 210/250
Adjustments
©
Danfoss | May 2018
520L0848 | AX00000087en-US0308 | 37