Danfoss 51 Series Service Manual page 7

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Service Manual
Series 51 and 51-1 Motors Service Manual
Troubleshooting
Check
Cause Corrective action
A
T.
Control orifices
Blocked or restricted orifice
causes
motor to shift
improperly.
Remove,
inspect and clean allorifices.
5. Pressure
compensator piston
or
spool
Sticking pressure compensator piston or spool
causes
controlto
hold motor at minimum
displacement.
Remove and inspect
control
spool and sensing piston.
Repair or replace if necessary.
6-
Controlspoolor piston
Sticking 4-way spool
or
control piston
causes
motor to shift
improperly.
Remove and inspect 4-way spool and control
piston.
Repair
or replace
if necessary.
7.
Two position solenoid
Two position
control not shifting motor to
maximum displacement.
lnspect solenoid valve for bent stem or bad coil.
Repair
or replace
if necessary.
8.
Control
input
signal lmproper control input
signal causes
motor to
stay
at
minimum
displacement.
Correct control input
signal.
9.
Threshold setting
lmproper threshold
setting causes
improper motor
displacement for torque
required.
Check
and adjust threshold setting.
10. Internal leakage
Excess
internal
leakage causes
charge pressure to
decay, reducing
output torque.
Install loop flushing defeat option and monitor
case
flow.
lf case
flow
is
excessive,
motor
may require major
repair.
Contact your
Danfoss Service
Provider.
1 1
008567
.
Rev BA
.
June
201
4
31