Troubleshooting - Danfoss PVG 32 Service Manual

Service
Manual
PVG 32
Proportional Valve Group
PVG 32
Component Troubleshooting
Pressure relief valve
Description: Adjustable relief
valve.
Adjustment
range
50 Bar
[700
PSI]
to
350
Bar
[5000 PSI].
Location:
The
relief
is
in
all
PVP
Inlet modules
Function:
Provides maximum pressure
setting above
pump
pressure setting
30
Bar
t450
PSll
Delta for
open center and closed inlet sections
Failure mode
Cause Corrective action
Will not build pressure
Contamination
While under pressure, back out to minimum
pressure
and allow
oil
to
leak by for approx.
5
seconds and then
readjust
to
correct
pressure -
Replace valve
External leaking
Damaged
seat
and
poppet
Replace complete assembly
Pressure setting
is
wrong
Pressure
adjustment
backs
off (on open
center application)
Adjust to model
code specification
Instability when
PC
and
inlet relief
has
too low of
a
delta between
them
PC at
pump
should be set 20 bar below relief
valve
Adjust to
model code specification
Serviceability: Non
servicea
ble.
Valve removal
tool
P/N:
155L6485. Torque to
20 Nm ['|80 lbf,in].
Pressure reducing
pilot valve
Description:
Pressure
reducing
valve at fixed pressure.
Location:
The pressure reducing valve
is a
option
in
some pvp Inlet modules.
Function:
Provides 10-15 bar
il45-218
psil internal pressure
for electrical (PVE) actuators or provide
25
Bar
(360
PSI)
(PVHC) and supply for external remote hydraulic actuators
(HRC). These pressures are only
present when the
load pressures are high enough to
satisfy
the required regulated
pressure. The open
center
system
at low pump flow
may only develop 9 Bar (130
pSl)
Failure mode
Cause
Corrective
action
Main spools
are slow,
driven by
PVE
13 Bar [190
PSI]
pilot
system
Contamination
Disassemble and clean
Pump pressure too low - below
9 Bar [130
PSl] Closed center:
System increase stand-by
to I3
Bar
Il90
PSII
Open center:
Check
gear per
pump
manufacture procedure
Check system
for other components
before valve inlet that
may
provide
a
path tank
High tank
port
pressure. Do not
exceed 40 Bar
t580 PSll
tank
pressure (For
PVPs
withoutT0
option)
Clear
restrictions
in return system.
Oilviscosity 460 mm2/5
t2128 5U5l
too high
(cold oil or incorrect viscosity oil)
Warm up system or replace oilwith
correct viscosity
Main spools will
not
move
mechanically or electrical
ForT0
option
only
not
being connected to
tank or restricted to tank
Connect T0 (PVP)
port
option to
tank or remove restriction
Internal pressure reducing valve parts
misassembled
Reassemble
the
internal pressure reducing valve parts correctly
1
1039167
.
Rev
BA.
May
2014