Bypass Function; System Schematic For Single Pump - Danfoss H1P 045 Service Manual

Service Manual
H1P 045/053/060/068 Axial Piston Single Pumps
Operation

Bypass Function

14 | © Danfoss | June 2020
The bypass function allows a machine or load to be moved without rotating the pump shaft or prime
mover. The single pump HPRV valve also provides a loop bypass function when each of the two HPRV hex
plugs are mechanically backed out three full turns.
Engaging the bypass function mechanically connects both A & B sides of the working loop to the
common charge gallery.
Possible damage to hydromotor(s).
Excessive speeds and extended load/vehicle movement must be avoided. The load or vehicle should be
moved not more than 20% of maximum speed and for a duration not exceeding 3 minutes. When the
bypass function is no longer needed, care should be taken to re-seat the HPRV hex plugs to the normal
operating position.
Bypass function not available for tandem pumps.

System Schematic for Single Pump

The schematic below shows the function of an H1P axial piston variable displacement pump with electric
displacement control (EDC).
M14
C2
C1
F00B F00A
M4
CW
M5
M6 1 2
R1
M3 L2 MA
A
B
S L4 MB
P003 418E
AX152886481964en-000405