Danfoss 90 Series - Default Chapter; Table of Contents

Introduction
Overview..............................................................................................................................................................................................5
Warranty.............................................................................................................................................................................................. 5
General instructions........................................................................................................................................................................ 5
Safety precautions............................................................................................................................................................................6
Unintended machine movement..........................................................................................................................................6
Flammable cleaning solvents.................................................................................................................................................6
Fluid under pressure..................................................................................................................................................................6
Personal safety.............................................................................................................................................................................6
Symbols used in Danfoss literature............................................................................................................................................7
Design...................................................................................................................................................................................................7
The system circuit.............................................................................................................................................................................8
The basic closed circuit.............................................................................................................................................................8
Case drain and heat exchanger..............................................................................................................................................9
Operation
Charge pump...................................................................................................................................................................................11
Charge relief valve.........................................................................................................................................................................11
Multi-function valves....................................................................................................................................................................11
Pressure limiter and high pressure relief valves................................................................................................................. 12
System check valves......................................................................................................................................................................12
Bypass valves...................................................................................................................................................................................12
Speed sensors..................................................................................................................................................................................13
Filtration options............................................................................................................................................................................13
Pressure override (POR) – 180 frame size only....................................................................................................................13
Manual displacement control (MDC)......................................................................................................................................14
Non-Linear MDC.............................................................................................................................................................................14
Solenoid override valve for MDC..............................................................................................................................................14
Neutral start switch (NSS)............................................................................................................................................................14
Hydraulic displacement control (HDC).................................................................................................................................. 14
Electric displacement control (EDC)........................................................................................................................................15
Automotive control (FBA II B)....................................................................................................................................................15
3-Position (FNR) electric control...............................................................................................................................................15
Operating parameters
Overview........................................................................................................................................................................................... 16
Input speed...................................................................................................................................................................................... 16
System pressure............................................................................................................................................................................. 16
Charge pressure..............................................................................................................................................................................16
Charge inlet pressure....................................................................................................................................................................17
Case pressure...................................................................................................................................................................................17
Temperature and viscosity......................................................................................................................................................... 17
Fluid and filter recommendations........................................................................................................................................... 17
Technical specifications
Overview........................................................................................................................................................................................... 19
Features and options....................................................................................................................................................................19
Operating parameters..................................................................................................................................................................19
Fluid specifications........................................................................................................................................................................19
Initial start-up procedure
General ..............................................................................................................................................................................................21
Start-up procedure........................................................................................................................................................................21
Pressure measurement
Required tools.................................................................................................................................................................................22
Port locations and gauge installation.....................................................................................................................................22
Troubleshooting
Overview........................................................................................................................................................................................... 25
Neutral difficult or impossible to find.....................................................................................................................................25
System operating hot...................................................................................................................................................................25
Service Manual
Series 90 Pumps
Contents
520L0818 • Rev 0101 • August 2015 3