Danfoss Series 42 Service Manual - Page 7
Browse online or download pdf Service Manual for Water Pump Danfoss Series 42. Danfoss Series 42 7 pages. Axial piston closed circuit pumps
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Service
Manual
series 42
Axial Piston closed
circuit
Pumps
Troubleshooting
System
will not
operate
in
one
direction
Neutral
difficult
or
impossible
to
find
Item
Description
Action
SCR
(system
check/
reliefl valves
The
SCR
valves are
malfunctioning or
improperly
set.
Verify
that
the
SCR
valves are
operating
and properly
set. Repair
or replace
them
as
necessary.
Displacement limiters
Displacement
limiters
may
be
improperly adjusted
such
that
the
servo piston
is
locked
in place.
Veri[t that
the displacement
limiters
are
adjusted to
the
proper setting.
Item
Description
Action
Input control
signal (linkage,
current, or
pressure)
The
pump
is
receiving
a
faulty
control
signah (MDC
-
binding
or broken
linkage;
EDC -
faulty
or inadequate
electricalsignal;
HDC -
blocked
or
incorrectly
orificed control
lines).
Verifu
that
the input
signal
is
correct
and identical in
both
dlrections. Adjust,
clean,
repair, or
replace
the
control
module
as
necessary.
SCR
(System
Check/Relie0 valves
The
SCR
valves are
malfunctioning or
improperly
set.
Veriff
that
the
SCR
valves are
operating
properly.
Repair
or
replace
them
as
necessary.
Pump
control
A
damaged or biased pump
control
may be
sending
a
signal
commanding
the pump
to
stroke only in one
direction.
Veri$r
that
the
pump's
control
is
functioning
properly.
Repair
or
replace
it
as
necessary.
Servo
pressure
The
drain or supply path
to
one
side
of
the servo piston may be bfocked.
Veriff
that the servo supply and drain
paths
are
unobstructed
and
that
any
orifices
are of
the
correct
size
and free
of
debris.
Clean
or repair
them
as
necessary.
Displacement limiters
(if
equipped)
The
displacement limiters
may
be
improperly adjusted such that
the
servo piston
is
prevented
from moving
in
one
direction.
Verifu
that the displacement
limiters
are
adjusted properly.
Item:
Description
Action
Input control
signal (linkage,
current, or
pressure)
The
pump
is
receiving
a
faulty
control
signal: (MDC -
binding
or broken
linkage;
EDC
-faulty
or inadequate
electricalsignah
HDC
- blocked
or
incorrectly
orifi
ced
control
lines).
Veriff
that
the input
signal
is
correct
and identical in
both
directions. Adjust,
clean, repair,
or replace
control module
as
necessary.
System pressure
With no
input
signal to the control,
a
pressure
delta may exist between
the
two
sides
of the
working
loop.
Readjust
pump
neutral setting.
Refer
to
adjustment
procedure.
Servo
pressure
With no
input signalto
the control,
a
pressure
delta may
exist across
the
seruo
piston.
Readjust
the controf
neutral setting.
Refer
to adjustment
procedure.
PCP
pressure
(EDCs
only)
Wth
no
input signalto
the control,
a
pressure
difference
may
exist
across
the
controlspool.
Replace
the
EDC.
52010638
.
Rev
0300 .
July
201 5