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Parker Hannifin Corporation
Proportional DC Valves
Series D*FC, D*1FC
Operation Manual
D_FC 5715-686 UK 07.02.2019
Troubleshooting table
4. Product information
Other applicable standards / rules
• ISO 4406:1999-12 Hydraulic fluid power - Fluids
- Method for coding the level of contamination
by solid particles
• ISO 4401:2005-07 Hydraulic valves; mounting
surfaces and connecting plates
• DIN EN 60204-1; VDE 0113-1:2007-06 Safety of
machinery – Electrical equipment of machines
– Part 1: General requirements
• DIN EN 60529; VDE 0470-1:2000-09 Degrees
of protection provided by enclosures (IP code)
• DIN EN 61000-4-2/3/4/6/8 Electromagnetic
compatibility
• DIN 51524-1:2006-04 Pressure fluids - HLP
hydraulic oils - Part 1: Minimum requirements
• DIN 51525-2:2006-04 Pressure fluids - HLP
hydraulic oils - Part 2: Minimum requirements
• German Occupation Safety Ordinance (Be-
triebssicherheitsverordnung)
• German Labour Protection Act (Arbeitsschutz-
gesetz)
malfunction at hydraulic load runtime
- generally no function
- high frequent oscillation
- low frequent oscillation
- one way operation only
- speed variations at unchanging command
- different speeds depending on travel direction
- speed too low
- drifting without command
- poor dynamic
possible reasons for malfunction corrective actions
X hydraulic pump resp. motor defective replace hydraulic pump resp. motor
X X X X X X X drive overloaded reduce pressure resp. speed, increase valve size
X X X X X X X X valve contaminated clean pressure fluid, filter / flush valve
X X X hydraulic fluid too viscous / too cold change fluid grade, provide operational temperature
X X X too low oil level within tank refill pressure fluid
X X X filter contaminated clean resp. replace filter
X supply voltage carries too much ripple reduce ripple
X X X command signal too low increase command signal
X command signal carries too much ripple reduce ripple
X X center position adjustment incorrect check center position adjustment
X X X X X contacts of central connector contaminated clean contacts / replace plug
X feed cable interrupted fix feed cable
X X X X X X X wiring sequence incorrect correct wiring sequence
X X feed cable without shielding change cable grade
X pilot pressure too low or failed increase pilot pressure to min. 20 bar
X X X pilot pressure too low increase pilot pressure to min. 20 bar
X pilot pressure too low increase pilot pressure to min. 50 bar
Trouble shooting
Basis of troubleshooting is always a systematic
approach. At first the following questions have to
be checked:
• Are there practical experiences with similar
failures?
• Have system adjustments been changed?
Afterwards starting of troubleshooting by means of
a priority list of the most likely reasons.
For suspect of a sluggish spool the valve may
be flushed with clean pressure fluid.
Troubleshooting in a hydraulic system requires
in either case a systematic approach. The
work may exclusively be performed by
qualified personnel, as it requires detailed
knowledge about function and construction
of the system. Reversals or disassemblies
may not be taken imprudently! Prior to the
works it has to be clarified, if the system has
been operated properly until the failure oc-
cured.
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