Overview..............................................................................................................................................................................................5

Warranty.............................................................................................................................................................................................. 5

General instructions........................................................................................................................................................................ 5

Safety precautions............................................................................................................................................................................6

Symbols used in Danfoss literature............................................................................................................................................7

Overview..............................................................................................................................................................................................8

Description of change.....................................................................................................................................................................8

Overview..............................................................................................................................................................................................9

General description and cross-sectional view....................................................................................................................... 9

The system circuit.......................................................................................................................................................................... 10

Pump features................................................................................................................................................................................. 10

Filtration options............................................................................................................................................................................12

Displacement limiters...................................................................................................................................................................14

Charge check / high pressure relief valves........................................................................................................................... 14

Bypass valves................................................................................................................................................................................... 15

Auxiliary mounting pads............................................................................................................................................................. 15

Manual displacement control (MDC)......................................................................................................................................17

Electrical displacement control (EDC).................................................................................................................................... 17

High current electrical displacement control (HC-EDC).................................................................................................. 18

Non-feedback proportional hydraulic (NFPH) control..................................................................................................... 18

Non-feedback proportional electric (NFPE) control.......................................................................................................... 19

Forward-Neutral-Reverse (FNR) three-position electric control................................................................................... 20

Specifications...................................................................................................................................................................................22

Required tools................................................................................................................................................................................. 23

Port locations and pressure gauge installation.................................................................................................................. 23

Ports and pressure gauges......................................................................................................................................................... 23

General...............................................................................................................................................................................................25

Start-up procedure........................................................................................................................................................................ 25

Recommendations........................................................................................................................................................................ 26

Overview........................................................................................................................................................................................... 27

System operating hot...................................................................................................................................................................27

System response is sluggish...................................................................................................................................................... 27

System will not operate in either direction.......................................................................................................................... 28

System will not operate in one direction.............................................................................................................................. 29

Neutral difficult or impossible to find.....................................................................................................................................29

Overview........................................................................................................................................................................................... 30

Displacement limiter adjustment............................................................................................................................................ 30

Pump neutral adjustment...........................................................................................................................................................32

Control neutral adjustment for MDC and EDC/HC-EDC.................................................................................................. 33

Standard procedures.................................................................................................................................................................... 35

Size and torque for plugs and fittings.................................................................................................................................... 35

Charge relief valve......................................................................................................................................................................... 37

Optional speed sensor................................................................................................................................................................. 39

520L0638 • Rev 0300 • July 2015