Service Kit Instructions
Series 51
Pressure compensator over-ride
PROCEDURE:
1.Install new O-rings on the pressure compensator over-ride valve block and retain with petroleum jelly.
2.Install the PCOR valve block on the multi-function block and install the screws.
3.Torque the screws to 11 Nm (8 ft•lbf).
4.Perform the PCOR pressure adjustments as described below.
ADJUSTMENT:
WARNING
The following procedure will require the vehicle/ machinetobedisabled(wheelsraisedo theground, work function disconnected, etc.) while performing the adjustments to prevent injury to the technician and/or bystanders.
The PCOR may be adjusted with the screw on the PCOR valve block attached to the multifunction block. The setting pressureisthatsystemgaugepressureatwhichthePCOR causes the motor displacement to start to increase. On a teststandthispointiswhensystemflowbeginstoincrease. Onamachine,withthemotorshaftlockedfromturning,this point is when maximum servo pressure becomes higher than minimum servo pressure.
In order to measure the PCOR setting pressure on a test stand, monitor system gauge pressure and system flow. Provide a signal to the motor control to maintain the motor at minimum displacement. Increase the system pressure until system flow just starts to increase. The system pressureatthispointisthePCORsettingpressure.Toadjustthe setting, loosen the lock nut with a 1 1/16 inch hex wrench.
Turn the adjusting screw, with a large screw driver or a |
1/2 |
inch hex wrench until the desired setting is established. Clockwiserotationoftheadjustmentscrewwillincreasethe pressure setting approximately 1200 psi (83 bar) per turn.
While holding the adjusting screw from turning, torque the locknut to 52 Nm (38 ft•lbf).
In order to measure the PCOR setting pressure on a machine, monitor the system gauge pressure (M1 or M2 gaugeport),minimumservopressure(M3gaugeport),and maximum servo pressure (M4 gauge port). Apply the parking brake, block the load, etc. to keep the motor shaft from turningduringthistest.CAUTION:Takenecessaryprecautions to prevent personal injury if machine or load should move during this test. While watching the gauges, very slowlyincreasethepumpdisplacement,therebyincreasing system pressure gradually (or use the pressure limiter adjustment screw on the pump to increase the system pressure gradually). Minimum servo pressure will increase with the system pressure. At about 50 psi below the PCOR set point the minimum servo pressure will stop increasing withsystempressureandthemaximumservopressurewill begin to increase. As system pressure is increased farther, minimum servo pressure will begin to decrease and maximumservopressurewillbegintoincrease.Whenmaximum servopressurebecomes50to100psihigherthanminimum servo pressure the motor servo piston will begin to move toward maximum displacement. The system pressure at this point is the PCOR setting pressure. To adjust the setting,loosenthelocknutwitha1 1/16 inchhexwrenchand turnadjustingscrewuntilthedesiredsettingisestablished. Clockwiserotationoftheadjustmentscrewwillincreasethe pressure setting approximately 1200 psi (83 bar) per turn. While holding the adjusting screw from turning, torque the lock nut to 52 Nm (38 ft•lbf).
© Danfoss, 2013 |
BLN-10118 • Rev AA • September 2013 |
1 |
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