Danfoss H1 Service Manual

Also see for H1 Series: Technical information Technical information Technical information Technical information Technical information

Contents

Neutral adjustment (EDC) (bottom view)Solenoid shaftFeedback pinAdjustingscrew(cam)P106 046EMaximumadjustmentless than 120°Control spoolIllustration shows how eccentric cam on adjusting screw rotates to adjust neutral.Mechanical neutral adjustmentW WarningUnintended movement of the machine or mechanism may cause injury to the technician or bystanders.To protect against unintended movement, secure the machine or disable/disconnect the mechanismwhile servicing.Mechanical neutral is set with the pump running at 1800 min¯¹(rpm). To set neutral, you must stroke thepump in each direction. You can do this with a small movement of the eccentric screw on EDC controls,however non-feedback controls (NFPE/FNR) lack this mechanism. To stroke a pump with non-feedbackcontrol, you must provide a 100 Hz PWM signal to the control solenoids. If you perform this adjustmentwith the pump installed in a vehicle or machine, safely elevate the wheels or disconnect the mechanismto allow safe operation during adjustment.This procedure details setting neutral for the entire pump, one side at a time. The procedure is the samefor each side of each pump so you will need to repeat it four times to set mechanical neutral for both thefront and rear sections. Alternate M4/M5 and MA/MB to zero out forward and reverse directions of thefront unit, then move the gauges to M4/M5 of the rear unit and MC/MD (system gauge ports for the rearunit). Refer to the drawing on the next page to identify all ports. The front and rear sections are basicallymirror images of each other. The control solenoids C1 and C2 are marked on each control.While performing this adjustment, you monitor the following pressures.:• Servo pressure at M4 and M5• System pressure at MA and MB or MC and MD• Pressure differential between M4 and M5 (optional)• Pressure differential between A and B or C and D (optional)Refer to Pressure measurements on page 26 and the illustration on the next page for gauge port locationsand information.Service ManualH1 45/53/60/68 Tandem Closed Circuit Axial Piston PumpsAdjustments42 | © Danfoss | June 2018 520L0928 | AX00000103en-US0303