Adjustments; Threshold Setting; Checking Threshold Setting; Adjusting Threshold Setting - Danfoss 51 Series Service Manual

Service Manual

Adjustments

Threshold Setting

12
Series 51 Electrohydraulic Proportional Controls Service Manual

Checking Threshold Setting

1. Install a 50 bar [600 psi] gauge at port M3 to read minimum servo pressure.
2. Install a 50 bar [600 psi] gauge at port M4 to read maximum servo pressure.
3. Install meter to read signal current.
4. Increase the signal current to the proper setting.
The pressure at port M3 should rise to about 100 psi [6.89 bar] higher than the pressure at port M4.
This causes the servo piston to start to move toward minimum position. Signal current at this point is
the threshold setting.
On a test stand, increase signal current until the flow from the motor begins to decrease. The signal
current at this point is the threshold setting.

Adjusting Threshold Setting

1. Using a 10 mm wrench, loosen the locknut on the adjusting screw.
2. Using a 3 mm internal hex wrench turn the adjusting screw:
•
Clockwise (cw) to increase the setting
•
Counterclockwise (ccw) to decrease the setting.
3. While holding the position of the adjustment screw:
•
tighten the locknut
•
using a 10 mm wrench torque the locknut to 9 N•m [6.6 lbf•ft].
11009448 • Rev BA • July 2014