Danfoss 51 Series Service Manual
Electrohydraulic controls
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- Service manual (64 pages) ,
- Repair instructions (36 pages) ,
- Service kit instructions (2 pages)
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Summary of Contents for Danfoss 51 Series
- Page 1 MAKING MODERN LIVING POSSIBLE Service Manual Electrohydraulic Controls Series 51 A7, D7, D8, DA, DC, EE, EP, EQ, ER, ES, L1, L2, L7 powersolutions.danfoss.com...
- Page 2 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Revision history Table of revisions Date Changed July 2014 Danfoss layout July 2009 First edition 11009448 • Rev BA • July 2014...
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Page 3: Table Of Contents
Safety Precautions....................................5 Unintended Machine Movement............................5 Flammable Cleaning Solvents..............................5 Fluid Under Pressure..................................5 Personal Safety.....................................5 Hazardous Material..................................5 Symbols used in Danfoss literature............................6 Overview......................................6 General Instructions..................................7 Keep it Clean....................................7 Inspect for System Contamination............................7 Replace the O-rings and Gaskets............................7 Lubricate all Moving Parts................................7 Torque Procedure.................................. - Page 4 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Contents Pressure-Reducing Valve............................... 24 Schematic......................................25 Repair........................................26 Disassembly....................................26 Inspection....................................27 Assembly......................................27 EE Control Operation......................................29 General Description................................. 29 Repair........................................30 Disassembly....................................30 Inspection....................................31 Assembly......................................31 EP, EQ, ER, ES Controls Operation......................................33 General Description................................. 33 Schematics......................................34 Definitions....................................35 Repair........................................35 Control Housing Disassembly..............................35 PCOR Disassembly..................................36...
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Page 5: Safety Precautions
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Introduction Safety Precautions Always consider safety precautions before beginning a service procedure. Protect yourself and others from injury. Take the following general precautions whenever servicing a hydraulic system. Unintended Machine Movement Warning Unintended movement of the machine or mechanism may cause injury to the technician or bystanders. -
Page 6: Symbols Used In Danfoss Literature
A worldwide network of Danfoss Global Service Partners is available for major repairs. Danfoss Global Service Partners are trained by the factory and certified on a regular basis. You can locate your nearest Global Service Partner using the distributor locator at www.powersolutionsdanfoss.com. -
Page 7: General Instructions
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Introduction General Instructions Keep it Clean You can complete many repairs or adjustments without removing the unit from the machine, if the unit is accessible and you can thoroughly clean it before beginning any procedures. Cleanliness is a primary means of assuring satisfactory motor life on either new or repaired units. -
Page 8: Pressure Compensating Override (Pcor) Option
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Introduction Pressure Compensating OverRide (PCOR) Option The PCOR function allows the motor to match its displacement to the system load. The PCOR overrides the control command allowing the motor to increase displacement when system pressure reaches a set level due to load. - Page 9 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Introduction Max. displ. PCOR Multifunction Block P101 907 Control BPD option Brake defeat spool Shuttle valve PCOR adjuster PCOR spool P106 431E 11009448 • Rev BA • July 2014...
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Page 10: Threshold And Ramp Springs
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Introduction Threshold and Ramp Springs A threshold spring and ramp spring(s) act on the opposite end of the 4-way valve. The threshold adjustment screw (S100) varies the threshold spring force. This changes the signal current required to move the 4-way valve and start the change in displacement. -
Page 11: Pressure Measurements
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Pressure measurements Port Locations and Gauge Installation Series 51 Motors Main ports A+B side port P101 204E Axial port System pressure A+B Guage port M1+M2 Main port B Axial port Main port A P101 204E Legend... -
Page 12: Adjustments
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Adjustments Threshold Setting 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. -
Page 13: Pressure Compensator Override (Pcor) Setting
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Adjustments Locknut and Threshold Locknut 10 mm 9 Nm [6.6 lbf•ft] Spring seat P101 911 Pressure compensator Override (PCOR) setting PCOR Adjustment In order to measure and adjust the start pressure setting for the PCOR function: 1. -
Page 14: Checking Pcor Setting On A Test Stand
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Adjustments An alternate method to slowly increase the system pressure is to use the pump’s pressure limiter (PL) valve. Lower the PL setting below the PCOR setting. Stroke the pump to about one-fourth displacement. -
Page 15: Pcor
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual PCOR Optional PCOR Housing Repair Disassembly 1. Remove plugs (N27). Remove and discard O-rings (N27A). 2. Using a 1 inch hex wrench, remove plug (N23). Remove and discard O-ring (N23A). 3. Remove locknut (N14). 4. - Page 16 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual PCOR 3. Position PCOR on multiblock. Install screws (N29). Torque using a 5 mm internal hex wrench to 16 N•m [12 lbf•ft]. 4. Lubricate and install spool and spring guide assembly (N20). 5.
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Page 17: Multifunction Block
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Multifunction block Optional Multifunction Block Repair Disassembly 1. Using a ¼ inch internal hex wrench, remove plugs (N26). Remove and discard O-rings (N26A). 2. Remove the spool (N30). 3. Using a 1/8 inch internal hex wrench, remove plugs (N27). Remove and discard O-rings (N27A). 4. -
Page 18: Inspection
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual Multifunction block Legend (continued) Item Wrench size Torque 8 mm internal hex 78 Nm [58 lbf•ft] 80cc, 110cc 10 mm internal hex 110 Nm [81 lbf•ft] 160cc, 250cc Inspection Clean and inspect components for damage or foreign material. Replace damaged parts. Assembly 1. -
Page 19: A7, L1, L2, L7 Controls
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual A7, L1, L2, L7 Controls Operation General Description The A7, L1, L2, L7 controls consist of a ported housing mounted directly on the end cap. It contains a check valve. A direct acting proportional solenoid, with a pushpin, is mounted onto the housing. This solenoid is high-current. - Page 20 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual A7, L1, L2, L7 Controls A7, L1, L2, L7 controls F324 M18A M16A P101 908 11009448 • Rev BA • July 2014...
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Page 21: Schematic
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual A7, L1, L2, L7 Controls Schematic A7, L1, L2, L7 Schematic Loop flush Max. displ. Check valve Solenoid P101 904 Repair Removing Solenoid Solenoid (M1) is available as complete assembly only. Do not remove the solenoid unless it is being replaced. - Page 22 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual A7, L1, L2, L7 Controls Controls G420 M16A O-ring M1A Solenoid stem M1 coil O-ring Plastic P101 915 Legend Item Wrench size Torque 8 mm internal hex 78 Nm [58 lbf•ft] (80, 110) 10 mm internal hex 110 Nm [81 lbf•ft]...
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Page 23: Inspection
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual A7, L1, L2, L7 Controls 5. Using a 5mm internal hex wrench remove orifice (M12) 6. Remove check-valve assembly (M10). If necessary, tap the housing on a hard surface to remove the check valve assembly. 7. -
Page 24: D7, D8, Da, Dc Controls
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual D7, D8, DA, DC Controls Operation General Description The D7 and D8 controls consist of a ported housing with an electric pressure-reducing valve, a pressure compensator override valve (PCOR), and an optional hydraulic brake pressure defeat (BPD) spool. For these controls, there must be external servo supply pressure fed to the M5 port (25 bar [363 psi] minimum, 50 bar [725 psi] maximum). -
Page 25: Schematic
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual D7, D8, DA, DC Controls Schematic D7, D8 Schematic Max. displ. PCOR Pressure reducing valve P101 905 DA, DC Schematic Maximum PCOR T7 T8 X3 (M5) Pressure reducing valve P107 875E 11009448 •... -
Page 26: Repair
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual D7, D8, DA, DC Controls Repair Disassembly Solenoid (M1) is available as complete assembly only. Do not remove the solenoid unless it is being replaced. 1. Using a 3 mm internal hex wrench remove screws (M15). 2. -
Page 27: Inspection
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual D7, D8, DA, DC Controls Legend (continued) Item Wrench size Torque M24, N84 1/8 internal hex 6 Nm [4 lbf•ft] Item Wrench size Torque 1/4 internal hex 37 Nm [28 lbf•ft] 3 mm internal hex 3.7 Nm [2.7 lbf•ft] 1/8 internal hex... - Page 28 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual D7, D8, DA, DC Controls 12. Using a 1/8-inch internal hex wrench, torque plugs (M24) to 6 N•m [4 lbf•ft]. 13. Install PCOR spool (M20). Install spring (M18). 14. Using a 13 mm wrench, install the Z* adjuster. 15.
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Page 29: Ee Control
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EE Control Operation General Description The EE controls consist of a ported housing mounted directly on the end cap. The ported housing has a piston and a pushpin that contact the 4-way valve (F32), and a ball-check valve. A pressure control pilot (PCP) is mounted on the control housing. -
Page 30: Repair
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EE Control Repair Disassembly 1. Using a 5/32 inch internal hex wrench remove screws (M32). 2. Remove the PCP (M30). The PCP has no repairable parts. EE Controls G420 M48A M16H P101 934 Legend Item... -
Page 31: Inspection
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EE Control Legend (continued) Item Wrench size Torque 10 mm internal hex 110 Nm [81 lbf•ft] (160, 250 cc) 5/32 internal hex 6 Nm [4 lbf•ft] 4 mm internal hex 7 Nm [5 lbf•ft] Item Wrench size Torque... - Page 32 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EE Control 4. Install the spring guide (M20). 5. Install pin (M26). and Install piston (M24). 6. Make sure pin (M26) fits into 4-way valve (F32). Caution Read BLN-10181 for minor repair instructions for the F32 4-way valve, threshold spring, and ramp spring components, if their repair is necessary 7.
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Page 33: Ep, Eq, Er, Es Controls
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls Operation General Description The EP, EQ, ER, ES controls consist of a ported housing mounted on the multifunction block. The ported housing has a piston and a pushpin that contact the 4-way valve. A pressure control pilot (PCP) is mounted on the control housing. -
Page 34: Schematics
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls Schematics E*-A1 Schematic Max. displ. PCOR Multifunction Block P101 907 Control E*-A2 Schematic Max. displ. PCOR Multifunction Block P101 902 Control 11009448 • Rev BA • July 2014... -
Page 35: Definitions
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls E*-A5 Schematic Max. displ. Multifunction Block P101 903 Control Definitions E*-A1 is the electrohydraulic proportional with PCOR and BPD. E*-A2 is the electrohydraulic proportional with PCOR. E*-A5 is the electrohydraulic proportional without PCOR. -
Page 36: Pcor Disassembly
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls EP, EQ, ER, ES Control M1 (PCP) P101 945 Legend Item Wrench size Torque 4 mm internal hex 7 Nm [5 lbf•ft] M44, M32 1/4 internal hex 30 Nm [22 lbf•ft] 5/32 internal hex 20 Nm [15 lbf•ft]... -
Page 37: Multifunction Block Disassembly
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls PCOR N22&N20 N8 7 N27A N27A P101 952 N23A Legend Item Wrench size Torque 1/8 inch internal hex 7 Nm [4 lbf•ft] 1 inch 40 Nm [30 lbf•ft] U6, U7 3 mm internal hex 6 Nm [4 lbf•ft]... -
Page 38: Control Orifices
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls Multifunction Block N240 N27A N1A1 P101 954 Legend Item Wrench size Torque 8 mm internal hex 78 Nm [58 lbf•ft] 80cc, 110cc 10 mm internal hex 110 Nm [81 lbf•ft] 160cc, 250cc Item... -
Page 39: Inspection
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls Control Orifices (optional) P101 958 Inspection 1. Inspect the multifunction block, shuttle spool, PCOR spool, and PCOR valve housing for damage or foreign material. 2. Clean all internal passages thoroughly. Replace worn or damaged components as necessary. Multifunction Block Assembly 1. -
Page 40: Inspection
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls Install Multifunction Block N240 N26A P107 830 Legend Item Wrench size Torque 8 mm internal hex 78 Nm [58 lbf•ft] 80cc, 110cc 10 mm internal hex 110 Nm [81 lbf•ft] 160cc, 250cc Item... -
Page 41: Control Housing Assembly
Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls PCOR Valve Assembly N22&N20 Z001 Z002 N23A P101 956 Legend Item Wrench size Torque 1/8 inch internal hex 7 Nm [4 lbf•ft] 1 inch 40 Nm [30 lbf•ft] U6, U7 3 mm internal hex 6 Nm [4 lbf•ft]... - Page 42 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual EP, EQ, ER, ES Controls EP, EQ, ER, ES Control M1 (PCP) P101 945 Legend Item Wrench size Torque 4 mm internal hex 7 Nm [5 lbf•ft] M44, M32 1/4 internal hex 30 Nm [22 lbf•ft] 5/32 internal hex 20 Nm [15 lbf•ft]...
- Page 43 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual 11009448 • Rev BA • July 2014...
- Page 44 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual 11009448 • Rev BA • July 2014...
- Page 45 Service Manual Series 51 Electrohydraulic Proportional Controls Service Manual 11009448 • Rev BA • July 2014...
- Page 46 Phone: +86 21 3418 5200 Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products already on order provided that such alterations can be made without changes being necessary in specifications already agreed..
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