Danfoss PVG 32 Service Manual page 5

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Service
Manual
PVG
32
Proportional
Valve
Group
System
Troubleshootin
g
Cylinder/motor
operates
without
remote controller
being operated
Cylinder/motor
responds slowly to remote electrical
or hydraulic controller actuation
Erratic
cylinder/motor
response
to
electrical
or
hydraulic controller operation
Cause
Check
Corrective action
Cylinder/motor
load
too
high
for
pressure settings of system
Check
load pressure at
PVB-LS
port
Reduce
load pressure if exceeds
maximum pressure limit
of the system
Maximum system pressure
should
be
approx.
25
Bar [365
PSIJ
above highest load pressure
Adjust maximum system pressure if
necessary
Adjust
pump
pressure
compensator setting
if
necessary
Cause
Check
Corrective action
Spool
control tension
rod loose Confirm torque on spoolcontroltension rod
Torque
to
I
Nm I70 lbf.inl
Electrical feedback transducer not in
neutral position
Checkthe feedback pin
in
the
PVE.
lt should
be loose
Replace
transducer
Remote
electrical
controller
neutral
position switch faulty
Disconnect the connection
at
the
PVE.
lt should come
back
to
neutral
Repair or replace
faulty
switch
orwiring
at
remote
controller
Sticking pressure
control
valve
in remote
hydraulic controller
Disconnect the
hydraulic signal linefrom valve
Repair or
replace
faulty
remote hydraulic
controller
Sticking main spool
in valve section
Remove
manual, electrical, and hydraulic actuators
from the
valve section.
Remove main spoolfrom
valve section and
inspected for
damage. lf no damage reinstallthe main valve
spool. Spool should move freely
in the valve section bore.
Replace the valve module and main spool if
any damage
is
found
on the main spool
Internal
fault
in
the
PVE/PVEH/PVEM/
PVEO
PVEO
check continuity.
All
other
PVE,
check
LED
(Fed
means
internal error)
Replace
faulty
PVE/PVEH/PVEM/PVEO
Contamination in the
hydraulic
oil
Take oilsamples to confirm
Flush hydraulic system.
Fill
with
clean
filtered
oil.
Cause
Check
Corrective action
Insuffi
cient system pressure
lnstall pressure gauge and record pressure
lf pressure
is
low adjust pressure
setting to valve
specification or pu
m
p manufacturers specification
Main spool travel limited
Check stops on manual lever controller
end
for proper
adjustment.
Refer to
Co m
po nent
trou bl
es h o
oti
n
g section.
Adjust the
manual
lever
stops and torque
the
jam
nuts
to
8
Nm
[70lbf.in] Do
notexceed
maximum torque
lncorrect signal voltage from
electrical
controller
Checkthe signalvoltagefrom
the controller with
a
volt meter
lf signal voltage
is
incorrect repair or
replace electrical
controller
Incorrect hydraulic pressure signal
from
remote hydraulic controller
Check pressure from the
remote hydraulic
controller-
25 Bar t360
PSll
lf
pressure
is
too
low, repair or replace remote hydraulic
controller per manufacturers instructions.
Insufficient
pilot oil-
all sections
Check
pilot for
contamination
and correctly
assembled
parts
- l0-15
bar [145-21S
psi]
Electric - Z5
bar [360
psi] Hydraulic
Replace
inlet
module
NOTE: Check
with
S-D TST
Insufficient
LS
pump
stand by
pressure
Check
pilot
PSl
-
1
0-'l 5 bar [145-21
I
psi]
Electric
-
25
bar [360
psil Hydraulic
Adjust or replace pump
Flow
is
not load independent
PVLP check
for
cracks
Check
L5
pressure vs load pressure
Replacevalve
Cause
Check
Corrective action
Electrical actuator faulty
Check
signalfrom controller
to
PVE
.
Repair or replace
PVE
Main spool centering spring
damaged
Check tension rod for correct torque or damage
Torque to
I
Nm [70lbf.in] or replace
1
1039167 .
Rev BA
.
May 2A14