Danfoss 51 Series Service Manual

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Danfoss 51 Series Service Manual Manual pdf 32 page image

OverviewW WarningThis service procedure may require disabling the vehicle / machine (raising the wheels off the ground,disconnecting the work function, and so forth) while performing, in order to prevent injury to thetechnician and bystanders. Take the necessary safety precautionsAdjust components of the Series 51 and Series 51-1 motors per following procedures (where necessary,refer to Pressure measurements on page 23, for gauge port locations and sizes):Charge pressure relief valveSet the charge pressure relief valve to the model order code specifications. In most applications, themotor charge relief valve is set 2 to 4 bar [29 to 58 psi] below the setting of the pump charge relief valve(measured with the pump in its neutral or zero-angle position). This setting assumes a reservoirtemperature of 50° C [122° F]. Charge pressure is referenced (additive) to case pressure.Measuring charge pressure1. Install a 0 to 60 bar [0 to 1000 psi] pressure gauge in port M1 or M2 (use which ever is at low looppressure).2. Install a 0 to 60 bar [0 to 1000 psi] gauge in port L1 or L2 to measure case pressure.3. Operate the system with the prime mover at normal operating speed and the pump at half stroke(forward or reverse).Series 51 charge pressure relief valveAdjustmentplug11/16lock nutP101 208EOlder Series 51 and Series 51-1 motors may be equipped with an external screw adjustable chargepressure relief valve (not shown).Adjusting charge pressureW WarningIncorrect charge pressure settings may result in the inability to build required system pressure and / orinadequate loop flushing flows. You must maintain the correct charge pressure under all operationconditions to maintain pump performance1. Loosen the lock nut using a 11/16 hex wrench.2. Turn the adjustment plug with a large screwdriver or 13mm hex wrench.Clockwise rotation of the plug increases the setting, and counterclockwise rotation decreases thesetting. The charge pressure setting will be reduced or increased at a rate of approximately 3.4 bar [50psi] per turn.Service ManualSeries 51 and 51-1 MotorsAdjustments32 | © Danfoss | March 2016 11008567 | AX00000013en-US0202