Hydraulic Oil Supply; Electrical Supply - Danfoss PVG 32 Service Manual

Service Manual
PVG 32 Proportional Valve Group
System Troubleshooting
Cause
Main spool position feedback
transducer signal incorrect
Contamination in hydraulic oil
Air in hydraulic pilot lines
Hydraulic remote actuator faulty
Low hydraulic oil supply

Hydraulic oil supply

Cause
Pump not running
Insufficient oil in reservoir
Leaking or burst supply hose
Relief valve malfunction
Isolating valves are closed
Faulty pump control
Low standby pressure in PVP - open
center pump
Low standby pressure in pump
control - variable pump
PVP pressure relief valve faulty
PVP orifices blocked
Internal filters blocked
Supply lines blocked
Internal hydraulic pilot pressure
insufficient
Blocked LS galleries
Shuttle valves faulty

Electrical supply

Cause
No electrical power
Neutral position switch faulty
18 | © Danfoss | February 2017
Check
Check feedback pin for damage
Take oil sample
Check for air trapped in signal lines from the
controller to the valve section module
Check signal pressure from the remote hydraulic
controller
Check fluid level in reservoir
Check
Check prime mover for operation
Check condition of drive coupling
Check fluid level in reservoir
Inspect lines to valve stack
Check for contamination and operation of relief valve Repair or replace relief valve
Check that all isolating valves are open and clear
Check pump compensator for correct operation and
setting per pump manufacturers
Check idle standby pressure - 10 Bar [145 PSI]
Check condition of compensator spool spring
Check pump LS control for operation and setting
Stand by pressure should be 15 bar [220 psi]
minimum
Check pressure relief valve spool and spring for
freedom of operation
Check PVP orifices for blockage
Check for blockage in internal filters
Inspect supply lines for blockages
Inspect pilot oil pressure reducing valve for proper
operation
Check LS galleries for blockage
Check LS system shuttle valves for wear and damage
Check for contamination per specification HPP 030. Refer to Design Guideline for Hydraulic Fluid
Cleanliness, Technical Information Manual 520L0467. If fluid is out of spec., flush hydraulic system and fill
with clean filtered oil.
Check
Check electrical circuit
Verify emergency stop switch is in the proper operating position
Check operation of neutral position switch in remote controller (if
connected in circuit) PVRE/PVRES/PVREL
Corrective action
Replace PVE
Flush complete system.
Fill reservoir with clean filtered fluid per OEM
specification
Bleed air from the hose connection at the valve section
Repair or replace cylinder/motor
Fill reservoir with clean filtered fluid per OEM
specification
Corrective action
Repair or replace prime mover
Repair or replace drive coupling
Fill with clean filtered oil
Repair or replace damaged hose
Repair or replace pump compensator per pump
manufacturers recommendations
Replace
Replace module due to worn components
Repair or replace LS control per pump manufacturers
procedures
Replace
Remove blockage
Remove blockage
Remove blockage
Repair or replace
Clean blockage from LS galleries
Replace as needed
Corrective action
Repair as needed
Reset
Replace switch
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