Danfoss H1T 045 - Default Chapter; Table of Contents

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Introduction

Hydrostatics Servicing Overview................................................................................................................................................5

General Servicing Instructions.....................................................................................................................................................5

Safety Precautions............................................................................................................................................................................6

Independent Braking System................................................................................................................................................. 6

High Inlet Vacuum...................................................................................................................................................................... 6

Manufacturer’s Warranty..........................................................................................................................................................6

Symbols used in Danfoss literature............................................................................................................................................6

The Basic Closed Circuit................................................................................................................................................................. 8

Case Drain and Heat Exchanger..................................................................................................................................................8

Tandem Pumps Design.................................................................................................................................................................. 9

H1T pumps pictorial diagram....................................................................................................................................................10

H1T Tandem Pumps Schematics..............................................................................................................................................11

System Schematic for Tandem Pumps...................................................................................................................................12

Operation

Pressure Limiter Valves................................................................................................................................................................ 13

Pressure Limiter Sectional View.......................................................................................................................................... 13

High Pressure Relief Valve (HPRV) and Charge Check Valve..........................................................................................14

HPRV/Charge Check Valve Sectional View......................................................................................................................14

Charge Pressure Relief Valve (CPRV)....................................................................................................................................... 16

Electrical Displacement Control (EDC)...................................................................................................................................16

EDC Operation...........................................................................................................................................................................17

Manual Override (MOR)............................................................................................................................................................... 18

Manual Displacement Control (MDC) ....................................................................................................................................18

MDC Operation..........................................................................................................................................................................19

MDC Torque................................................................................................................................................................................20

Neutral Start Switch (NSS)..................................................................................................................................................... 20

Case Gauge Port M14..............................................................................................................................................................20

Control-Cut-Off (CCO) and Brake Release Valves............................................................................................................... 20

Operating Parameters

Input Speed......................................................................................................................................................................................23

Independent Braking System...............................................................................................................................................23

System Pressure..............................................................................................................................................................................23

Servo Pressure.................................................................................................................................................................................25

Charge Pressure..............................................................................................................................................................................25

Charge Pump Inlet Pressure.......................................................................................................................................................25

Case Pressure...................................................................................................................................................................................25

External Shaft Seal Pressure.......................................................................................................................................................26

Temperature....................................................................................................................................................................................26

Viscosity.............................................................................................................................................................................................26

Technical Specifications

H1 Pumps General Specification..............................................................................................................................................27

Technical Data for H1 Tandem Pumps...................................................................................................................................27

Operating parameters for H1 Tandem Pumps....................................................................................................................28

Fluid Specification......................................................................................................................................................................... 29

Fluid and Filter Maintenance Recommendations

Pressure Measurements

Port locations and gauge installation - 045/053.................................................................................................................31

Port locations and gauge installation - 060/068.................................................................................................................32

Initial Startup Procedures

Start-Up Procedure........................................................................................................................................................................33

Troubleshooting

Safety Precautions......................................................................................................................................................................... 35

High Inlet Vacuum....................................................................................................................................................................35

Unintended Machine Movement....................................................................................................................................... 35

Service Manual