21
Lib
er
at
ors
Troubleshooting Charts
XI
Symptom
Probable Cause
Corrective Action
7)
(Cont.)
Low flow at oxygen
outlet on all LPM
settings (cont.)
d)
Flow
control
valve
inlet
filter
screen
dirty
Clean or replace (RPxx) the filter screen.
e)
Economizer valve faulty
Test the economizer (RP28) and replace (RP29) if necessary.
f )
Blockage
in
the
liquid
withdrawal
circuit or the flow restrictor
Check
the
warming
coils
and
withdrawal
tubes
as
well
as
the
flo
w
restrictor
for
blockages. Replace if necessary.
g)
FCV faulty
Replace the FCV (RP30)
8)
Increased NER
a)
Saturation
Pressure
is
too
high
Inspect
the saturation pressure of the reservoir. Allow at least 30 minutes at
no flow for the
reservoir to saturate properly.
b)
Leak in the system
Perform a leak check on the plumbing (RP16). Repair leaks as necessary.
c)
Relief valve open
Ensure that there is no venting from the relief valves. If there is refer to the
corrective actions for “Excessive venting from relief valves (hissing sound)”
.
d)
Partial
or complete los
s
of
vacuum
Conduct
the
NER
test (RP32) and
return
the
unit
to CAIRE, Inc.
,
if
necessary.
9)
Excessive Frost:
NOTE: Minimal frost
on the shroud and on
the plumbing
is normal. This
symptom applies
to frost that is
much greater than
what is normally
observed.
a)
Frost is acceptable
Some
frost
on
the
shroud
and on the plumbing is acceptable,
especially
at
high
flow
rates during continuous use. This is due to the evaporation of LOX to gas and the
temperature
difference
between the LOX and room temperature.
b)
High humidity level
High humidity levels can increase frost accumulation.
c)
Saturation
pressure is too
h igh
Inspect
the saturation pressure of the reservoir. Allow
at least 30 minutes at no flow for the reservoir to saturate properly.
d)
Leak in the system
Perform
a
leak
check
on
the
plumbing (RP16).
Repair
leaks
as
necessary.
e)
Relief valve open
Ensure that there is no venting from the relief valves. If there is refer to the
corrective actions for “Excessive venting from relief valves (hissing sound)”
f )
Partial or complete loss of vacuum
Conduct the NER test (RP32) and return the unit to CAIRE, Inc. if necessary.
10)
Unit will not maintain
acceptable
system
pressure
a)
Saturation pressure is
unacceptable
Inspec
t the saturation pressure of
the
reservoir
used
for filling .
. Allo
w at
lea
st 30
minut
es at
no flow for the portable to saturate properly.
b)
Vent valve not completely closed
Close vent valve. Leak check vent valve outlet and stem. Replace or repair as needed.
c)
Leak in the system
Perform a leak check on the plumbing (RP16). Repair leaks as necessary.
d)
Economizer valve faulty
Test the economizer (RP28) and replace (RP29) if necessary.
e)
Primary releif valve faulty
Test the primary relief valve (RP13) and replace (RP14) if necessary
11)
High Pressure at
Reservoir oxygen
outlet
a)
Saturation
pressure
is
too
high Inspect the saturation pressure of the reservoir. Allow at least 30 minutes at
no flow for the reservoir to saturate properly.
b)
Primary reli
e
f valve set too high or
relief
valve
operating
improperly.
Perform relief valve test. Replace as needed.
c)
Economizer
valve stuck in
closed state
Perform Economizer test. Replace as needed.
d)
Parti
al
or
complete
lo
ss of vacuu
m
Conduct
the
NER
test (RP32) and
return
the
unit
to
CAIRE, Inc.
if
necessary.
12)
Contents
indicator
reads incorrectly
a)
Battery
voltage
to
o low to
operate
contents indicator
Replace
battery
as
needed
(RP5)
then
calibrate
the
meter
following
(RP6)
b)
Sensor wires not connected properly,
pinched or otherwise damaged
Visually inspect the meter harness assembly from the meter to the point
where the sensor wire enters the reservoir manifold. Replace as necessary
.
c)
Contents
indicato
r not
calibrated
properly
Calibrate the meter as needed following (RP6).
d)
Ice crystal in reservoir causing
incorrect or empty level reading
Empty and warm the reservoir following (RP23, RP24) to melt and evaporate
moisture from inside the reservoir.
e)
Meter
malfunctioning/
damaged
Inspect for physical damage. Replace meter as necessary then recalibrate the
meter follow-ing (RP6)
Liberators Technical Service Manual • PN 13350704 Rev
K
