This service manual was designed to provide Sunrise Medical
Respiratory Products Division qualified service technicians
and homecare providers with the proper maintenance, service, safety, and repair procedures for the DeVilbiss Oxygen
Concentrator.
Read and understand all the information contained in this service manual before attempting to operate or perform any
aintenance on the concentrator.
m
An oxygen concentrator is a device that delivers highly con-
entrated oxygen for therapeutic applications.
c
Room air is a mixture of 78% nitrogen, 21% oxygen, 1% argon
and other gases.The concentrator draws in room air, separates
the nitrogen from the oxygen, and delivers concentrated oxygen to the patient through an oxygen port.
For more in-depth classroom type training, Sunrise Medical
holds oxygen concentrator service schools. For service
school information, contact the Respiratory Technical Service
Department at
NOTE:
1-800-333-4000 (814-443-4881).
Sunrise Medical reserves the right to alter or change the
design of the DeVilbiss Oxygen Concentrator series. Hence, slight
differences in construction or components may exist between the
unit in hand and what is described in this manual.
3
LT-1928
GENERAL INFORMATION
IMPORTANT SAFEGUARDS
Read all instructions before operating the oxygen concentrator. Important information is highlighted by these terms:
WARNING: Safety information for hazards that might
cause serious injury or death.
AUTION: Information for preventing damage to
C
the product.
OTE:
N
nformation to which you should pay special attention.
I
SAFETY PRECAUTIONS AND GENERAL WARNINGS
A. Federal (U.S.A.) law restricts this device to sale by or on the
order of a physician.
B.
WARNING: Oxygen promotes rapid burning. Do
not smoke when using this unit or when near a
person receiving oxygen therapy. Do not operate the
oxygen concentrator within a minimum of five feet
(1.6m) from hot, sparking, or burning objects or naked
flames. Do not use in rooms heated by paraffin or
portable gas heaters.
C. Do not place a humidifier with an oxygen patient unless pre-
scribed by a physician and then only a bubble-type humidifier
should be used.
D. Do not connect the oxygen concentrator to an electrical out-
let controlled by a wall switch; the outlet should be independent of other appliances.
E. Do not use an electrical adapter or extension cord with the
oxygen concentrator.
F. Only operate the oxygen concentrator with all filters in place;
do not operate if the air filter is wet.
WARNING: Electric shock hazard. Do not remove cabi-
G.
et.The cabinet should only be removed by a qualified
n
Sunrise Medical homecare provider.
H. WARNING: Disconnect the power cord from the wall
outlet before attempting repairs on the unit. Extra
care should be taken if it is necessary to operate the
unit with the cabinet removed.
I. WARNING: Do not use oils, greases, or any petrole-
um-based solvents/cleaners on or near the unit. Use
only materials that are compatible with oxygen.
J. WARNING: Electric Shock Hazard.When replacing
the capacitor, do not touch the terminals or allow
metal objects to come in contact with the terminals
on the capacitor. The capacitor may hold a charge for
several days after the unit is turned off.The capacitor
is located in the base of the unit next to the cooling
fan.
K. Use only Sunrise Medical concentrator replacement parts and
accessories.
L. Do not use regenerated sieve material.
LT-1928
4
UNPACKING AND SETUP
INITIAL INSPECTION
It is suggested that an initial inspection be performed upon
receiving the oxygen concentrator.
1. After removing the DeVilbiss Oxygen Concentrator from the
carton, examine it for any external damage. If shipping damage
has occurred, contact the Sunrise Medical Customer Service
Department at 1-800-333-4000 (814-443-4881) for specific
instructions. Save the carton for possible later return; note
the position of the unit and placement of the packing material.
2. Open the filter door (Figure 3) and record the number of
hours on the hour meter. Check to make sure the air filter is
n place.
i
3. Check to be sure the intake bacteria filter (Figure 4) is in place.
4. Plug the unit into an electrical outlet, turn the unit “On,” and
check the audible and visible alarms.
5. Set the flow meter to maximum recommended liter flow and
let the unit run for at least 20 minutes.
6. Use an oxygen analyzer to check the concentration.
NOTE: If the unit fails to operate properly (oxygen concen-
tration not within specification) or if internal damage is found,
contact the Sunrise Medical Customer Service Department at
1-800-333-4000 (814-443-4881).
PATIENT SETUP
1. Position the unit near an electrical outlet in the room where
the patient spends most of his or her time.
NOTE: Do not connect to an electrical outlet controlled by a
wall switch.The outlet should be independent of other appliances.
2. Position the unit at least 6 inches (16 cm) from walls,
draperies, or any other objects that might prevent the proper
flow of air in and out of the oxygen concentrator.
3. Locate the unit a minimum of 5 feet (1.6 meters) from fireplaces, radiators, heaters, and hot-air registers.
Oxygen Tubing Only Connection (Figure 1)
1. Thread the cannula fitting (part #CN100) onto the oxygen
utlet port.
OST15, OST25, or OST50), not to exceed 50 feet (15
meters), directly to the humidifier bottle outlet fitting.
NOTE: For optimum performance, the DeVilbiss Oxygen
Concentrator has a preset nominal output pressure of 8.5 psi
(58.6 kPa). Use only “bubble-type” humidifiers. Do not use
“jet-type” humidifiers.
NOTE: Condensation from the humidifier may occur in
longer lengths of tubing or if the tubing is laying on a cold
floor. This can be reduced by using a removable humidifier
stand (part #MC44DM-509).
To use the stand:
1. Attach a straight humidifier adapter fitting (part #444-506) to
the bottle by turning the wing nut on the humidifier until it is
tight on the fitting.
2. Secure the bottle in the strap.
3. Attach one end of the oxygen tubing to the oxygen outlet on
the unit and the other end to the plastic adapter fitting on the
humidifier. Locate the humidifier near the patient.
WARNING: Oxygen promotes rapid burning. Do
not smoke when using this unit or when near a
person receiving oxygen therapy. Do not operate the
oxygen concentrator within a minimum of 5 feet (1.6
meters) from hot, sparking, or burning objects or
naked flames. Do not use in rooms heated by paraffin
or portable gas heaters.
W
ARNING: Electric Shock Hazard. Only qualified
Sunrise Medical homecare providers may remove
the cabinet.
4. Attach the appr
opriate o
xygen accessories (o
xygen tubing or
humidifier) to the oxygen outlet port.
NOTE: A maximum of 50 feet (15 meters) of tubing plus 7
feet (2.1 meters) of cannula plus a bubble humidifier is allowed
between the concentrator and the patient.
When ready for operation
1. Attach the nasal cannula (part #CAN00), catheter, or face
mask to the oxygen tubing (per the man
2. Follow the
5
Operating Instructions on the next page.
ufacturer’s directions).
LT-1928
UNPACKING AND SETUP
OPERATING INSTRUCTIONS
1. Remove the power cord completely from the strap. Make sure
the power switch is in the “Off” position.
2. 115 Volt Units– Insert the plug into an electrical outlet.The
DeVilbiss Oxygen Concentrator uses a two-prong polarized
plug and is double-insulated to protect against electric shock.
WARNING:The plug on the DeVilbiss 515ADZ and
515ADS concentrators has one blade wider than the
ther.To reduce the risk of electric shock, this plug is
o
intended to fit in a wall outlet only one way. Do not
attempt to defeat this safety feature.
WARNING: Improper use of the power cord and plugs
can cause a burn, fire, or other electric shock hazards.
Do not use the unit if the power cord is damaged.
WARNING: Oxygen promotes rapid burning. Do
not smoke when using this unit or when near a person receiving oxygen therapy. Do not operate the oxygen
concentrator within a minimum of five feet (1.6m) from
hot, sparking, or burning objects or naked flames. Do not
use in rooms heated by paraffin or portable gas heaters.
3. Press the power switch to the “On” position.When the unit is
turned on, the “Service Required” light will illuminate and an
audible signal will sound (the patient alert system) momentarily. The “Power” light also illuminates.
Only DeVilbiss Oxygen Concentrators with OSD
®
The OSD is an optional device within DeVilbiss concentrators
that monitors the o
xygen produced b
y the unit.The OSD
operates as follows:
• Normal Oxygen (green light) - oxygen purity normal
NOTE: If the oxygen purity continues to fall, an audible signal
will sound intermittently. If the oxygen purity continues to fall
to a low enough level, the yellow “Low Oxygen” light will turn
off and the red “Service Required” light will turn on.
OTE:Refer to Specificationsfor specific alarm settings.
N
When the unit with the OSD is turned “On,” all four indicator
ights (Power, Service Required, Low Oxygen, and Normal
l
Oxygen) on the front panel will briefly illuminate. After a few
seconds, only the “Power” and “Normal Oxygen” lights will
remain on.
NOTE: After Power On, the OSD conducts a continuous
diagnostic evaluation to check for a fault in the piezo electronics. If this condition is detected by the OSD electronics at any
time during concentrator operation, the green “Normal
Oxygen” OSD light will turn off and the beeping audible and
blinking red “Service Required” light alarms activate.
Otherwise for the first fifteen minutes of operation, the
green “Normal Oxygen” light will remain illuminated
during the oxygen stabilization process.After that
time, the OSD will begin monitoring the oxygen purity
every second.
4. Slowly turn the flow meter knob until the flow meter ball is
centered on the line next to the appropriate flow rate.
NOTE:When the flow meter knob is turned clockwise, the
flow decreases (and eventually will shut off the oxygen flow).
When the knob is turned counter-clockwise, the flow increases.
NOTE: Use low output flow meter (part #515LF-607) for
flow rates under 1 lpm.
NOTE:The unit may require up to 20 minutes for the oxygen
concentration and flow rate to stabilize.The flow rate should
be monitored and readjusted if necessary.
5. The flow meter has a locking device. If it is necessary to preset
and lock in the prescribed flow rate, tighten the set screw
located on the hex nut just below the control knob using a
1/16" Allen bit. No adjustment can be made without loosening
the set scr
ew.
6. The DeVilbiss oxygen concentrator is now ready for use.
LT-1928
6
MAINTENANCE
PATIENT ALERT SYSTEM
The DeVilbiss Oxygen Concentrator patient alert system will
detect unit component failure.This system is comprised of both
isible and audible alarms which signal the patient if a malfunction
v
should occur.
The visible alarm located on the front panel (Figure 1) reads
“Service Required.” The audible alarm system is internally
powered; no batteries are required.When the indicator lights
illuminate or the audible alarm sounds, other than during unit
start-up, a problem has occurred.
Non-OSD models:
Power Failure (Blinking red “Service Required” light
•
and pulsing audible alarm)
• Low Flow (Continuous red “Service Required” light and
audible alarm)
OSD models:
• Power Failure (Blinking red “Service Required” light
and pulsing audible alarm)
• Low Flow (Below 0.5 lpm) (Continuous red “Service
Required” light and audible alarm)
• Below Normal Oxygen (84% to 75%, yellow “Low Oxygen”
light. 75% to 60%, yellow “Low Oxygen” light and beeping
audible alarm. Less than 60%, red “Service Required” light
and beeping audible alarm.) Refer to
Specifications for spe-
cific alarm settings.
The visible and audible alarms will activate for approximately
15 minutes in a no power situation. If the unit is turned “On”
without power or power is removed later, no alarm will sound
for the first 10 seconds.After that time, the alarm will produce
an audible pulse every few seconds while the visible alarm
blinks. Power for this alarm is provided by a capacitor on the
PC board.
NOTE: If the concentrator has been unused for an extended
period, the unit must run several minutes before the power fail
alarm will activate.
The PC (printed cir
cuit) boar
d (Figure 5) is r
esponsible for
controlling the system and alarms.
TE:
NO
A high pr
(a “popping” sound) r
e located on the compressor head.
valv
essure condition is indicated b
elease of pr
essur
e fr
y the audible
om a pressur
e r
elief
ROUTINE PATIENT MAINTENANCE
The oxygen patient should perform the following maintenance:
Oxygen Humidifier (reusable bottles only)
The patient should clean the humidifier bottle daily. The patient
should follow the instructions supplied by the manufacturer. If
no cleaning instructions were supplied, these steps should be
followed:
• Wash the humidifier bottle in a solution of hot water and
dishwashing detergent.
• Soak the humidifier in a solution of one part white vinegar
to three parts hot water for 30-45 minutes.This solution
acts as a germicidal agent.
• Rinse thoroughly with hot tap water and refill with distilled
water for use. Do not overfill.
Cannula/Mask and Tubing
The patient should clean and replace the cannula or mask and
tubing as instructed by the manufacturer.
Air Filter and Oxygen Outlet Connector
The air filter (Figure 3) and oxygen outlet connector should
be cleaned at least once a week by the patient.To clean, these
steps should be followed:
1. Remove the air filter located in the door on the back of the unit.
Remove the oxygen outlet connector (if used) from oxygen outlet port (Figure 1).
2. Wash in a solution of warm water and dishwashing detergent.
3. Rinse thoroughly with warm tap water and towel dry.The filter should be completely dry before reinstalling.
WARNING: Do not attempt to operate the unit without the air filter or while the filter is still damp.
NOTE:
The air filter should be monitored more closely in
environments with abnormal amounts of dust and lint.
CAUTION: Operation of the DeVilbiss Oxygen
Concentrator in extr
air filter will pr
eme environments or without the
y occlude the intak
ematur
el
e bacteria
filter and cause a decrease in the unit performance.
Exterior Cabinet
The patient should clean the concentrator exterior cabinet by
using a damp cloth or sponge with a mild household cleaner
and wiping it dr
Every DeVilbiss Oxygen Concentrator is tested at the factory.
o assure continued trouble-free performance, the following
T
preventative maintenance should be performed by the homecare provider during periodic oxygen patient visits.Failure to
roperly maintain the unit will void the warranty.
p
1. Check the oxygen concentration with an oxygen analyzer
(part #O2ANA)—every 3 months on non-OSD units or every
two years on OSD units.
a. Calibrate the oxygen analyzer prior to checking the oxy-
en concentration.The analyzer should be properly cali-
g
brated using the manufacturer’s recommended procedure.
NOTE: Changes in temperature, altitude, or humidity may
affect the analyzer’s oxygen concentration reading.The analyzer should be calibrated in similar conditions to the location of
the concentrator.
b. The concentrator must operate for a minimum of 20 min-
utes before checking the oxygen concentration.
c. Connect the analyzer to the unit’s oxygen outlet port
(Figure 1) and wait until the display stabilizes.
d. Record the reading.
2. Check the audible alarm and indicator lights every two years.
When the power switch is turned “On,” listen for the audible
alarm and check to see if the front panel indicator lights are
operating.
3. Change intake filter as follows:
a. Extended life intake bacteria filter (part # 515DZ-605) -
Inspect once a year. Change as necessary, not to exceed
8760 hours.
b. Open the filter door and replace filter as required.
4. Change the final bacteria filter (part #PV5LD-651) every
two years or 17,520 hours.
a. Unplug the unit, remove the cabinet, and loosen the bib.
. Remove the hose from each end of the filter (Figure 8) and
b
discar
d the filter
.
c. Install the new final bacteria filter with the “IN” fitting
toward the flow meter.
d. Tighten the bib and replace the cabinet.
5. Check the system performance every two years of operation
by measuring the accumulator pressure swing. Use the
Accum
ulator Pr
described in the cha
pter
Component
essure Test
Testing, Repair and Replacement.
NOTE: This PM Schedule reflects:
• 5000 hour usage equal to one year
• a normal, clean operating environment.
The homecare provider is responsible for:
• determining the condition of the concentrator operating
environment.
• determining a preventative maintenance interval frequency
(not to exceed the schedule stated above which takes into
consideration the specific operating environment).
BETWEEN PATIENT MAINTENANCE
1. Discard oxygen tubing, cannula & humidifier bottle.
. Wash or replace the cabinet air filter.
2
3. Wash the concentrator cabinet.
4. Check oxygen concentration. If the unit falls within specifica-
tion, the extended life intake bacteria filter does not need to
be replaced between patients.
PREVENTATIVE MAINTENANCE SUMMARY
Patient
DailyClean the humidifier bottle (if used).
Weekly Clean air filter on back of unit.
Clean exterior of cabinet.
OtherClean and replace cannula/mask and tubing as
instructed by manufacturer.
Homecare Provider
Change intake bacteria filter as necessary following
requirements in step 3.
3 months Check oxygen concentration on non-OSD units.
Check the concentrator environment, and set a
maintenance interval of less than 3 months if
required.
2 years Check audible alarm and indicator lights.
Change final bacteria filter (change within 17,520
hours).
Check system performance.
Check oxygen concentration on OSD units.
LT-1928
8
TROUBLESHOOTING
SYSTEM OPERATION
The DeVilbiss Oxygen Concentrator uses a pressure swing
adsorption system.The air is drawn into the unit through air
ilters and into a double-head compressor.
f
A pneumatic diagram of the system is shown in Figure 14.
The compressed air passes through a rotary valve (Figure 5),
which is cycled at a pre-determined rate, and is directed into
ne of two sieve beds.The sieve beds contain molecular sieve
o
material which is a synthetically-produced inorganic silicate. It is
very porous and has the unique ability to selectively adsorb
itrogen from the air as it passes through the sieve bed.
n
s one bed is being pressurized, the other bed is quickly
A
depressurized.This allows the nitrogen that was adsorbed
during its pressurization cycle to be exhausted from the
sieve material.
The nitrogen is released through exhaust ports located on the
rotary valve assembly.The ports are connected to a single piece
of hose running from the valve to the exhaust muffler.
Also during each bed pressurization, a small amount of oxygen
flows through an orifice (Figure 9) from the pressurized bed
into the depressurizing bed.The orifice is clamped inside a long
piece of blue tubing connecting the outlets of the two sieve
beds.This helps purge the nitrogen from the depressurizing bed.
The beds will continue to be alternately pressurized and
depressurized as the unit operates.
Oxygen leaving the sieve beds is directed through a check
valve to the accumulator tank.A pressure regulator (Figure 9)
on the tank controls the oxygen pressure as it leaves the accumulator and enters the flow meter.The flow meter allows the
oxygen flow to be controlled and adjusted to the level prescribed by the patient’s physician. From the flow meter the
oxygen passes through the final bacteria filter (Figure 8),a
check valve, and finally the oxygen outlet port to the patient.
The DeVilbiss Oxygen Concentrator operates on a timed
cycle.The cycling is controlled by the PC board.The PC board
will send voltage to the valve causing it to shift and alternately
essurize the sieve beds.
pr
The PC board also activates the electr
onic alarm system.
high pressure condition will be indicated with a “popping” type
sound produced by release of pressure from a pressure relief
e on the compressor head.
valv
w flow and po
Lo
wer failure are
indicated by audible and visible alarms.
The 515 OSD Models operating system incorporates “turn-
wn” technolog
do
y.The PC board constantly monitors the flow
rate and will decrease the cycle time whenever the flow rate
is less than 2.5 LPM.Therefore it “turns-down” the cycle based
er oxygen demand.As a result, the unit runs cooler
w
on lo
with less power consumption.
NORMAL OPERATING SEQUENCE
When the concentrator is turned “On,” the following cycling
sequence can be observed by attaching pressure gauges to the
ieve bed test points.
s
1. The rotary valve is quickly cycled several times to relieve residual bed pressure preventing a static condition in the compressor.This rapid cycling onl
y happens on start-up and is clearly
heard as pressure is being quickly exhausted several times
through the exhaust muffler that is connected to the valve.
2. The PC board applies a short DC voltage signal to the valve.
he valve will stop for approximately 7 seconds causing the
T
right bed to pressurize first while the left bed depressurizes to
approximately 2 PSI (14 kPa).
3. Voltage is again applied to the valve for a short time. The valve
will stop for approximately 0.7 seconds.During this time the
sieve bed pressures are equalized.
4. A short DC voltage signal is again applied to the valve.The
valve will stop for approximately 7 seconds causing the left
bed to pressurize while the right bed depressurizes to approximately 2 PSI (14 kPa).
5. A short DC voltage signal is again applied to the valve.The
valve will stop for approximately 0.7 seconds. During this time,
the sieve bed pressures are equalized.
6. The cycle then repeats with step 2.
NOTE:In the “turn-down” mode (OSD models only),the fixed
cycle time is decreased to approximately 3 seconds and the
bed pressure equalization time to approximately 0.3 seconds.
NOTE:High-end sieve bed pressure should not exceed 1/2 PSI
(4 kPa) above high-end accumulator pressures. Refer to
Specifications for normal pressures obtained during the cycle.
A
9
LT-1928
TROUBLESHOOTING
SIMPLIFIED TROUBLESHOOTING
The key to simple troubleshooting is to recognize which type
of problem exists and select the most effective approach to
olving the problem.The different types of problems and the
s
approaches for solutions are as follows:
WARNING: Mechanical Hazard. Keep fingers, loose
clothing, etc. away when working on compressor.
Type I—The unit runs but a low pressure and flow or high
pressure condition exists.
NOTE:
Low pressure or flow are indicated by both a visible
and audible alarm. High pressure is indicated by a “popping”
sound caused by the pressure relief valve.
1. Connect test gauges to sieve bed tests points (Figure 7).
2. Refer to the
Normal Operating Sequence to make sure the unit
is cycling properly.
3. If bed pressure is rising slowly, check for occluded filters and
severe leaks. If filters are clean and there are no leaks, then the
compressor is defective.
4. If the pressure relief valve is releasing pressure, observe
whether the unit is cycling or not.
5. If the unit is not cycling or has uneven bed pressures, this indicates that the rotary valve is not operating correctly. Refer to
Rotary Valve Testing described in the chapter Component
the
Testing, Repair and Replacement.
6. If the unit is cycling in conjunction with very high bed pressures, this indicates defective sieve beds.
Type II—The compressor will not start when the unit is
turned on.
1. Verify that the cooling fan is running; if it is not, determine
where you are losing power.
2. Check for compressor voltage at the compressor connector.
3. If voltage is present, then the capacitor or compressor is
defective.
4. If voltage is not present, the wire harness is defective.
Type III—The concentrator runs and continues to cycle
but has low oxygen concentrations.
1. Connect test gauges and check for higher or lower than normal bed pressures.
a. High pressures indicate defective sieve beds.
. Low pressures indicate occluded filters, leaks, or defective
b
compressor.
c. Uneven bed pressures indicate valve is not operating cor-
rectly.
2. Check for oxygen leaks at:
• sieve beds• flow meter
• accumulator tank• final bacteria filter
• pressure regulator• final check valve
• outlet port
NOTE: Check for leaks using a certified leak detection solution such as Snoop
®
or equivalent (must not contain ethylene
glycol).Apply leak test solution to all fittings and hose connections with unit running. If an air leak is present, the solution
will bubble.All leaks should be repaired before putting the unit
back in service.
CAUTION: Do not apply leak test solution to any part
of the rotary valve or the main PC Board assembly.
3. Test accumulator tank pressure. If pressure is lower than normal, then sieve bed check valves are defective.
NOTE: For normal system pressures refer to Specifications.
LT-1928
10
TROUBLESHOOTING
TROUBLESHOOTING CHART A
Visible AlarmAudible AlarmCompressorPower Light
OFFOFFONON
Other SymptomsPossible CausePossible Remedy
Pulsating air noiseIntake filter not in place or defectiveCheck filter and replace if necessary
Compressor intake hose disconnectedReconnect hose
Excessive noiseLoose or defective motor mountsReplace motor mounts
Defective compressorReplace compressor
efective cooling fanReplace cooling fan
D
luctuating oxygen flowOccluded humidifierClean or replace humidifier
F
Use of improper humidifierUse only a bubble-type humidifier
Occluded filtersClean or replace filters
Occluded or defective cannula and tubingDetach cannula from oxygen delivery tubing. If
proper flow is not attained, check tubing for
kinks or other obstructions. Clean or straighten
as required or replace tubing if necessary.
Use of excess oxygen tubingThe unit is designed to deliver 5 lpm with a
cannula on 50 feet (15 meters) of approximately
5/32” (4 mm) inside diameter tubing. Smaller
diameter tubing or the addition of any other
flow restriction may prevent obtaining the
desired flow rate.
Defective flow meterReplace flow meter
Leak in systemCheck for leaks in all hoses and fittings
Defective compressorReplace compressor
Defective compressor reed valveReplace compressor reed valve
Defective check valveReplace check valve
Pressure regulator not adjusted Adjust or replace pressure regulator
properly or defective
Little or no oxygen flowFlow meter not adjusted properlyAdjust flow meter
Hose disconnected to flow meterReconnect hose
Oxygen delivery tubing is kinked or blockedStraighten tubing or remove obstruction
Occluded humidifierClean or replace humidifier
Low oxygen concentrationLeak in systemCheck for leaks in all hoses and fittings
Unit has not been used for an extended Allow unit to run for 20 minutes and retry
sound during power failureperiod of time.
has been unused for an extended period,
the unit must run several minutes before
the power fail alarm will activate.
Def
Defective power switchReplace power switch
Defective wire harnessReplace wire harness
Audible alarm does not sound when
Defective PC boardReplace PC board
unit is turned “On”
Pressure relief valve activated -Defective PC boardReplace PC board
“popping” sound
Defective rotary valveReplace valve
Service Required light does not Defective PC boardReplace PC board
illuminate when unit is turned
“On”
Def
PC board connectors not properly latchedBe sure tabs are pushed completely into place
e not operating correctlyReplace valve
NOTE: If the concentrator
ective PC boar
e light
ectiv
dReplace PC board
Replace light
11
LT-1928
TROUBLESHOOTING
TROUBLESHOOTING CHART B
Visible AlarmAudible AlarmCompressorPower Light
BlinkingPulsingOFFOFF
Other SymptomsPossible CausePossible Remedy
Fan offLine cord not properly installed or defectiveInsert plug in receptacle or replace line cord
No power at receptacleCheck building circuit breaker or fuse, or have
ouse wiring checked by qualified electrician
h
Circuit may be fully loaded with other
appliances and another receptacle
may be required
xygen concentrator circuit breaker activatedPress the circuit breaker reset button
O
If unit circuit breaker opens again,check
internal wiring
Line cord quick-connect terminal inside Reconnect quick-connect terminal
unit is disconnected
Defective power switchReplace power switch
Defective circuit breakerReplace circuit breaker
TROUBLESHOOTING CHART C
Visible AlarmAudible AlarmCompressorPower Light
BlinkingPulsingONON/OFF
Other SymptomsPossible CausePossible Remedy
Fan and compressor operating.Blown fuse on PC boardReplace fuse
Pressure relief valve activated –Defective PC boardReplace PC board
“popping” sound
TROUBLESHOOTING CHART D
Visible AlarmAudible AlarmCompressorPower Light
ONONOFFON
Other SymptomsPossible CausePossible Remedy
Fan operatingMain wiring harness disconnected/defectiveReconnect/replace wiring harness
Unit warm to the touch and cannot Compressor overheated due to:
veral minutesOccluded filtersClean or replace filters
estarted f
be r
TROUBLESHOOTING CHART E
Visible AlarmAudible AlarmCompressorPower Light
ONON
Other Symptoms
Fluctuating or no flowSystem pressure below 9 psi (62.1 kPa) due to:
or se
Restricted input or output air passageRemove obstruction
Low or high line voltageCheck line voltage; use alternate circuit
independent of other a
Defective cooling fanReplace cooling fan
Defective compressorReplace compressor
ON
le Remedy
ossib
le Cause
ossib
P
Leak in systemCheck for leaks in all hoses and fittings
ective compressorReplace compressor
Def
P
ppliances
ON
LT-1928
12
TROUBLESHOOTING
TROUBLESHOOTING CHART F (OSD UNITS ONLY)
CompressorPower Light
ONON
Other SymptomsPossible CausePossible Remedy
No OSD lights are illuminated.Defective OSD.Check concentration with an oxygen analyzer.
If the concentration is within specification, replace
the PC board.
No OSD lights are illuminated,Oxygen level is low*Check concentration with an oxygen analyzer.
ut red “Service Required” light is If the concentration is within specification, replace
b
lluminated accompanied by a the PC board. If the concentration is low,
i
beeping audible alarm.refer to low oxygen concentration
symptom in
Both OSD lights are illuminated.Defective OSDReplace PC board.
Yellow Low Oxygen light Oxygen level is low*Check concentration with an oxygen analyzer.
is illuminated.If the concentration is within specification, replace
the PC board. If the concentration is low,refer to
low oxygen concentration symptom in
Troubleshooting Chart A.
Yellow Low Oxygen light Oxygen level is low*Check concentration with an oxygen analyzer.
is illuminated and an intermittent If the concentration is within specification, replace
audible alarm sounds every the PC board. If the concentration is low,refer to
five seconds.low oxygen concentration symptom in
Troubleshooting Chart A.
*Refer to Specifications page for oxygen purity levels.
Troubleshooting Chart A.
13
LT-1928
COMPONENT TESTING, REPAIR, AND REPLACEMENT
PROPER REPAIR PROCEDURES
The DeVilbiss Oxygen Concentrator is designed for ease of
service.To aid service personnel, a Service Kit (part #444-501)
s available which contains the necessary gauges, tools, and
i
testing instruments to properly service the oxygen concentrator. On parts that are sold separately, the part number is indi-
ated in parenthesis.
c
The following parts are included in the Service Kit:
Slotted bit
1
1 #1 Phillips bit
1 #2 Phillips kit
7/16” Socket l/4” Drive
1
1 Crescent wrench
1 8” Duckbill pliers
1 T-10 Bit
1 5/32” Allen bit
1 5/64” Allen bit
1 9/64” Allen bit
1 7/64” Allen bit
2 Presure/Vacuum gauge (part #PVO2D-601)
1 Tool box
2 Test Fittings (part #303DZ-637)
1 Torx screwdriver w/bits
1 AC/DC test light
1 1/4” Ratchet wrench
1 3mm Hexbit
1 T-15 Torx “L” wrench
1 10mm Socket l/4” Drive
1 1/4” Drive extension
1 Plastic storage case
1 Plastic error indicator tool
In addition to the Service Kit, an oxygen analyzer (part #O2ANA)
is needed to periodically check oxygen concentration levels. A voltmeter will be needed for more accurate voltage testing.
NOTE: Be sure to read all of the steps involved before beginning any of the procedures in this manual.
NOTE:After repairing or replacing a component run the unit for
20 minutes,
check the oxygen concentration and test for leaks.
Test for leaks using a certified leak detection solution such as
SWAGELOK #MS-Snoop
®
or equivalent (must not contain
ethylene glycol).Apply leak test solution to all fittings and hose
connections with the unit running.
If an air leak is pr
esent, the
solution will bubble.All leaks should be repaired before putting
the concentrator back in service.
y leak test solution to an
CAUTION:
Do not a
ppl
of the rotary valve or the main PC Board assembly.
WARNING:When servicing the DeVilbiss Oxygen
Concentrator
tools ar
, be absolutely certain that the correct
e fr
e used and that the par
ts ar
ee of oil and
grease or any material not compatible with oxygen.
®
Teflon
the male thr
tape is recommended and must be applied to
eads omitting the first thr
ead to eliminate
y part
the possibility of tape particles entering the oxygen system. LOX-8™ sealant may be used in place of Teflon
tape.
WARNING: Electric shock hazard. Do not remove cabinet.The cabinet should only be removed by a qualified
unrise Medical homecare provider.
S
WARNING: Disconnect the power cord from the wall
outlet before attempting repairs on the unit. Extra
care should be taken if it is necessary to operate the
unit with the cabinet removed.
CABINET REMOVAL
To remove front and back cabinets (Figures 2 & 3):
1. Ensure the unit is unplugged from the wall outlet.
2. Using a screwdriver, remove the six screws that hold the back
cabinet to the internal structure and the bib.
NOTE: All six screws are the same size.
3. Remove the back cabinet by sliding it toward the rear until clear.
4. Remove the front cabinet by pushing the top shoulders toward
the back of the unit, then outward away from behind the bib.
Tilt the top of the front cabinet forward until it can be pulled
out of the base of the unit.
The majority of all the servicing and repairs can be done without removing the front bib. However, to gain access to the
components behind the bib, it may be loosened or removed.
To loosen the bib (Figure 4):
1. Remove the two screws (located directly above the hour
meter) that hold the bib to the unit’s internal structure.This
will allow access to the components behind the bib.
To remove the bib completely (Figure 8):
Remove the two screws as above.
1.
2. Disconnect the ribbon connector from the PC board.
3. Disconnect the lines from the power switch and circuit break-
.
Mark these wires accor
.
er
dingly
4. Tilt the top of the bib forward to release it from the slot in
the body of the concentrator.
5. Remove the hose connected to the bottom of the flow meter.
To reassemble bib:
Reconnect the wir
1.
2. Insert the bib tab into the slot above the rotary valve, and
push until it snaps into place.
3. Secure bib with two screws.
eflon® is a r
T
X-8™ is a trademark of Fluoramics,
LO
Snoop® is a r
es and hose.
ed trademark of DuP
egister
ed trademark of SW
egister
ont.
Inc
A
.
GELOK
LT-1928
14
COMPONENT TESTING, REPAIR, AND REPLACEMENT
ACCUMULATOR PRESSURE TEST
To check accumulator pressures:
. Make sure the unit is “Off.”
1
2. Remove front and back cabinets.
. Use the pressure-vacuum gauge (part #PVO2D-601) and pressure
3
test assembly (part #303DZ-637) included in the Service Kit.
. Remove the tubing cap from the accumulator tank fitting and
4
attach the 1/16" (1.6 mm) diameter tubing from the gauge to
the accumulator tank fitting just vacated above.
5. Turn the unit “On” with the flow rate set to maximum recom-
mended flow.
During each timed cycle, the average pressure in the oxygen
accumulator will rise and fall.
NOTE: Normal pressures observed depend on altitude and
flow rate. Increases in altitude and flow rate will slightly
decrease accumulator pressures.Decreases in the two variables
will slightly increase accumulator pressures. Acceptable accumulator pressure swing ranges at various altitudes at the maximum recommended flow are identified in the
NOTE: A defective check valve may cause a rapid drop in
accumulator pressure below the minimum value.
NOTE: A defective compressor will be indicated by slowly
rising pressure. Pressure may only reach a certain level and
then stop.
Low oxygen concentration levels and accumulator pressures
higher than normal may indicate defective sieve beds. Severely
contaminated beds may also cause the pressure relief valve on
the compressor to open.
NOTE: A malfunctioning rotary valve will also cause high
accumulator tank pressure and activation of the pressure relief
valve. In this case it should be determined whether the problem is with the sieve beds, valve, or both.
CITOR
APA
C
The capacitor enables the compressor to start and run by sup-
oltage to the windings of the compressor motor. A
plying v
def
ectiv
e capacitor will r
esult in the compressor running slo
or not starting.
CAUTION: The 515ADS and 515ADZ concentrators
use either a Thomas compressor with a 15 mfd capacitor or a GSE compressor with a 22 mfd capacitor. If
replacement is necessary,be sure the correct capacitor is installed
.
CAUTION: The 515AKS and 515AKZ concentrators
use a GSE compressor with a 10 mfd capacitor. If
r
eplacement is necessar
tor is installed
.
y, be sure the correct capaci-
Specifications.
er
w
WARNING: Electric Shock Hazard.When replacing
the capacitor, do not touch the terminals or allow
metal objects to come in contact with the terminals
on the capacitor.The capacitor may hold a charge for
several days after the unit is turned off.
If a defective capacitor is suspected, a new one must be
installed.The capacitor is strapped into a well molded into the
ottom of the unit (Figure 10) next to the cooling fan.
b
To replace the capacitor:
1. Make sure the unit is unplugged from the wall outlet.
2. Remove the front and back cabinets.
3. Remove the compressor.
4. Disconnect the two wires from the terminals on the capacitor.
5. Cut the nylon cable tie holding the capacitor in place and
remove the capacitor.
6. Reconnect the wires to the new capacitor.
7. Install the new capacitor and secure with a new cable tie.
8. Replace the compressor.
9. Replace the front and back cabinets and secure with the
six screws.
COMPRESSOR
The DeVilbiss Oxygen Concentrator uses a double-head, oilfree compressor.The compressor is secured to the compressor plate with four rubber motor mounts.
A compressor that is worn or defective may:
• cause pressure to rise slowly.
• cause excessive noise and/or vibration.
• cause lower oxygen concentrations.
A worn or defective compressor can be caused by a defective
internal component such as:
• reed valve
• o-ring
• gasket
• cup seal
These components are included in the Compressor Service
Kit (part #515DZ-643,Thomas or #515ADZ-643, GSE).
CAUTION:
a Thomas compressor or a GSE compressor. Be sure
der the correct part number when rebuilding the
to or
compressor
NOTE:
off if it becomes overheated.This protects the compressor from
damage caused by heat build-up. (Some models have an auxiliary
thermostat mounted within the compr
NOTE: A pressure relief (PR) valve is located on the pressure
head to prevent high pressure build up in the system should a
component malfunction occur.
The 515A series concentrators use either
.
A built-in thermal cutoff switch will shut the compressor
essor compar
tment.)
15
LT-1928
COMPONENT TESTING, REPAIR, AND REPLACEMENT
To test the compressor operating voltage (Figure 4):
The compressor requires line voltage to operate. If the com-
ressor does not start when the unit is turned on, the voltage
p
input must be tested:
1. This voltage can be checked at the compressor connector
using a voltmeter or test light connected to the brown and
blue wires.The voltmeter is the best way to test.
2. If no voltage is detected, disconnect power and check for
loose or broken wires between the compressor connector
nd switch or wire harness.
a
3. If there is voltage at the compressor connector, then either
the capacitor or the compressor itself is defective.
To test the compressor for proper output:
NOTE: If the compressor is not providing a high enough
output the patient alert system may be activated.
1. Remove the front and back cabinets.
2. Connect pressure-vacuum gauges to the sieve bed test points.
See the
and Replacement
defective compressor will be indicated by slowly rising pressure. Pressure may only reach a certain level and then stop.
Sieve Bed Pressure Test in the Component Testing, Repair,
section for details on attaching the gauge.A
If these conditions are observed then:
• The unit filter(s) may be occluded—check the air filter and
intake filter for occlusions.
• There may be a severe leak in the system—check for air
leaks using a leak detection solution such as Snoop
equivalent (must not contain ethylene glycol).
CAUTION: Do not apply leak test solution to any part
of the rotary valve or the main PC Board assembly.
• The compressor reed valves, cup seal, or the compressor
itself may be defective (Figures 11A & 12A).
If the filters are not occluded and no leaks are found, the compressor m
ust then be removed and repaired or replaced.
®
or
To remove the compressor:
1. Make sure the unit is unplugged from the wall outlet.
y disconnecting the com-
Disconnect the compressor wir
2.
pressor electrical connector (Figure 4).
3. Remove the ladder clamp and hose from the outlet fitting on
the compressor (Figure 4).
4. Remove the two screws from the back of the compressor
mounting plate(s) (Figure 4).
ve the two 10 mm hex nuts that secure the mounting
Remo
5.
plate to the front of the compressor housing (Figure 6).These
nuts are located on each side of the rotary valve.
6. Lift compressor and mounting plate up and out of the com-
pressor housing area.
7. Remove the tubing from the compressor intake port fitting.
CAUTION: If the unit has been running recently, the
compressor may be hot.
es b
To inspect and/or replace internal components (
11A & 12A)
. Remove the eight screws that hold the compressor heads in
1
place.When removing the heads, be sure to keep each head
and its components with the correct compressor side.
2. Check for proper placement of or damage to the gaskets on
the bottom of the compressor heads. Replace if damaged.
3. Remove reed valve plates.A reed valve is located on each side
of the valve plate.
4. The compressor reed valves should be flush with the valve
plate. If the valve is broken or not flush with the valve plate, or
foreign matter is detected inside the head, clean or replace the
compressor reed valves.
:
Figures
To replace the compressor reed valves (Figures 11A
& 12A)
5. Check for proper placement of or damage to the rubber oring on the bottom of the valve plate. Replace if damaged.
6. Remove piston sleeves by pulling upward and inspect cup seal
on pistons. Replace if badly worn or damaged.
:
a. Remove the screw holding the compressor reed valves in
position on the valv
. Position the new reed valves so that they are centered and
b
completely cover the holes in the valve plate.
c. Place the metal retainer on the reed valves and secure
with the reed valve screw.
e plate and discard the used reed valves.
To replace cup seal (Figures 11A & 12A):
a. Remove rod screw from top of piston.
b. Remove the cup retainer plate.
c. Discard defective cup seal.
d. Place new cup seal into position.
e. Replace cup retainer plate.
f. Secure with screws.
7. Reposition sleeve on piston.
NOTE: In some cases, it may be easier to position sleeve on
piston bef
8. Place valve plates on the compressor so that heads of reed
valve screws are aligned with the indentation in top of pistons.
Install the compressor heads so that the holes in the heads are
9.
aligned with the holes in the compressor housing.
10. Secure compressor heads with the screws.
o replace the compressor:
T
NOTE: For mounting plate and motor mount removal, refer
to sections below.Also refer to steps used in removing the
compressor.
CA
use either a Thomas compressor with a 15 mfd capacitor or a GSE compr
515AKS and 515AKZ concentrators use a GSE com
pressor with a 10 mfd capacitor. If replacement is necessar
ore installing a new cup seal and retainer plate.
UTION:
The 515ADS and 515ADZ concentrators
essor with a 22 mfd ca
y, be sure the correct capacitor is installed
pacitor.The
-
.
LT-1928
16
COMPONENT TESTING, REPAIR, AND REPLACEMENT
1. Inspect the motor mounts. Replace if damaged. Secure the
mounting plate(s) to the bottom of the new compressor using
the four compressor mounting hex nuts.
2. Inspect the capacitor to determine if replacement is necessary
capacitor is included w/compressor purchase). If capacitor is
(
wrong value for compressor or replacement is desired, refer
to
Capacitor section.
3. Reconnect tubing to the compressor intake fitting.
4. Position compressor on the base of the unit so that the studs
n the mounting plates are aligned with notches on the front
o
of the unit base.
5. Secure mounting plate with two screws on the back and install
nuts on the front side of the plate.
6. Reconnect hose to the fitting at compressor outlet.
7. Reconnect the compressor electrical connector.
To remove compressor from the mounting plate:
1. Turn compressor upside down so that it is resting on the heads.
2. Remove the four compressor mounting hex nuts and mounting plate.
To remove motor mounts:
1. Unscrew studded motor mounts from compressor feet by
hand.
COOLING FAN
The cooling fan provides a constant air flow to cool the
compressor.The cooling fan is located in the bottom of the
unit below the compressor (Figure 10).
A defective cooling fan may cause the compressor’s internal
thermo-protective device to activate and shut the compressor
off. Should this condition occur, the compressor will require
several minutes for the thermo-protective device to reset.
If the cooling fan is defective, it must be replaced:
Make sure the unit is unplugged from the wall outlet.
1.
2. Remove the front and back cabinets.
3. Remove the compressor.
Disconnect the cooling fan terminals.
4.
5. Note the position of the fan and fan guard before removing
the four retaining screws that secure the fan to the base of
the unit.
6. Remove the defective fan and secure the replacement fan in
position with the four retaining screws.
NOTE:When installing the fan, be sure the air flow directional
ow on the side of the fan is directed away from the compressor
arr
and fan guard is reinstalled properly.
Reconnect the electrical connector
7.
.
Reinstall the compr
8.
essor
FINAL CHECK VALVE
This check valv
xygen outlet fitting.
the o
e is located betw
This check valv
.
een the final bacteria filter and
xygen to
ws o
e allo
flow only out of the unit.When the unit is turned off and oxygen flow stops, the check valve closes to prevent water from
being drawn into the unit.
A defective final check valve may allow water to be drawn in
rom the humidifier bottle when the unit is turned off.This
f
may occlude the final bacteria filter and/or the flow meter
causing a restriction of flow and making it difficult to adjust
he flow rate.
t
To replace the final check valve (Figure 8):
1. Make sure the unit is unplugged from the wall outlet.
2. Remove the front and back cabinets and loosen or remove the bib.
3. Remove the hose from the outlet side of the final bacteria filter.
4. Remove the two screws from the back of the oxygen outlet
fitting assembly and remove the assembly.
5. Remove the hose from each end of the final check valve.
6. Attach the hoses to a new check valve. Make sure that the
flat side of the check valve is directed toward the oxygen
outlet fitting.
7. Replace the outlet fitting assembly and connect the hose to
the filter.
8. Replace the bib and front and back cabinets.
FLOW METER
The pressure-compensated flow meter has an accuracy level of
±5% at full scale (exception: +0%,-5% at 5 lpm).The flow
meter on the DeVilbiss Oxygen Concentrator is designed for
use at 8.5 psi (58.6 kPa) at flow rates up to 5 lpm.
To check for leaks in the flow meter tubing:
1. Check for leaks using a certified leak detection solution such
as Snoop
2. Apply leak test solution to all fittings and hose connections
with the unit running.
CAUTION: Do not apply leak test solution to any part
of the rotary valve or the main PC Board assembly.
3. If an air leak is present, the solution will bubble.All leaks should be
epair
r
W
leak testing near electrical connections.
®
or equivalent (must not contain ethylene glycol).
e putting the concentrator back in service.
ed befor
ARNING: Electric Shock Hazard. Use caution when
To replace the flow meter (Figure 8):
1. Make sure the unit is unplugged from the wall outlet.
e the front and back cabinets.
v
Remo
2.
3. From behind the bib remove the 2 hoses from the flow meter.
4. While squeezing tabs on flow meter brackets, push the flow
meter through the bib.
5. Install new flow meter in bib and reconnect hoses.
17
LT-1928
COMPONENT TESTING, REPAIR, AND REPLACEMENT
HOUR METER
To replace the hour meter (Figure 9):
. Make sure the unit is unplugged from the wall outlet.
1
2. Remove the front and back cabinets and loosen the bib.
. Disconnect the hour meter connector from the PC board.
3
4. Remove the meter by carefully inserting a small flat screwdriv-
r under the outer edge of meter and prying upward.
e
5. Install a new hour meter by applying downward pressure until
it snaps into position.
6. Connect the hour meter to the PC board.
CAUTION: Do not apply any force or flex the PC
Board when connecting or disconnecting electronic or
pneumatic components. Damage to the electronic
assembly is possible.
MOLECULAR SIEVE BEDS
The two molecular sieve beds alternately remove the nitrogen
from the air passing through them and provide the patient
with a constant supply of oxygen.
The efficiency of the molecular sieve material will be impaired
if it becomes contaminated by moisture. Contamination causes
the molecular sieve material to lose its nitrogen adsorbing
properties resulting in a decrease in oxygen concentration.The
unit should run for a minimum of 20 minutes before turning
"Off" to prevent problems associated with moisture contamination in the system.
To test the sieve beds:
1. Remove the 1/16" plugged piece of tubing from the top of
each sieve bed.
2. Connect the pressure-vacuum gauges to the sieve bed test
points (Figure 9) in order to observe unit cycling and bed
pressures. Refer to the section on
Normal Operating Sequence.
3. If it is determined that the valve did not shift, refer to the sec-
tion on
Rotary Valve testing. However, if the unit is cycling prop-
erly allow unit to run while observing the sieve bed pressures.
After 20 minutes of operation, check the oxygen concentra-
4.
tion levels. Low oxygen concentration and high pressures indicate contaminated sieve beds.
NOTE:If the molecular sieve material is found to be no longer
effective, first locate the source of the malfunction or cause
(such as leaks) for contamination and take corrective action.
To replace the molecular sieve beds (Figures 5, 6, &7):
1.
Make sure any contamination problem has been corrected
before replacing.
Make sure the unit is unplugged from the wall outlet.
2.
3. Cut the plastic cable ties that secure the sieve beds to the
internal structure of the unit.
e the tubing from the fittings at the top of each sieve bed.
v
Remo
4.
ve the hose clamps and hose from the bottom of the
Remo
5.
sieve beds.
6. Install new sieve beds in reverse order using new plastic cable
ties. Position the new beds so that the bed serial number label
is at the top of the unit.
NOTE: Make sure that the sealing caps remain on the new
ieve beds until just prior to connecting hoses and tubing.
s
7. Leak test all connections with a certified leak detection solution
®
uch as Snoop
s
r equivalent (must not contain ethylene gly-
o
col).Apply leak test solution to all fittings and hose connections with unit running. If an air leak is present, the solution
will bubble.All leaks should be repaired before putting the unit
back in service.
CAUTION: Do not apply leak test solution to any part
of the rotary valve or the main PC Board assembly.
POWER CORD
To replace the power cord - 115 volt units only
(Figure 4):
1. Make sure the unit is unplugged from the wall outlet.
2. Remove the back cabinet.
3. Disconnect the power cord connector.
NOTE: Loosening or removing the compressor mounting
plate may make it easier to service the power cord.
4. Note wire colors and socket locations before removing wires.
5. Using a pair of duckbill pliers, squeeze the power cord strain
relief and pull it out of the base of the unit.
6. Insert a new power cord through the hole in the base of the
unit and secure with strain relief.
7. Insert sockets into connector housing and then reconnect the
power cord connector.
8. Replace back cabinet and secure with the six screws.
POWER SWITCH
To replace the power switch (Figure 8):
e sure the unit is unplugged fr
1. Mak
2. Remove the front and back cabinets and loosen the bib.
3. Note the position of the wires and switch before removing
the wires from the switch terminals.
4. While squeezing the locking tabs on the sides of the switch,
push the switch out of the front of the bib.
5. Install the new switch in the correct orientation making sure
that it locks into position.
6. Reconnect the wires to the switch terminals.
PRESSURE REGULATOR
The pr
essure regulator stabilizes the flow of oxygen to the
patient and establishes back pressure on the system. It is preset at 8.5 psi (58.6 kPa) and should not have to be adjusted in
the field.
om the wall outlet.
To test the pressure regulator:
urn the unit
T
1.
Set the flo
2.
“On.”
w meter at 2 lpm.
LT-1928
18
COMPONENT TESTING, REPAIR, AND REPLACEMENT
3. Use a pressure-vacuum gauge (part #PVO2D-601) and a fitting
suitable to fit on the oxygen outlet or on a short piece of tubing connected to the outlet.
4. If the pressure-vacuum gauge reads anything other than 8.5 ±
.
to the pressure regulator may be required. If so, call Sunrise
Service Department at
NOTE:
Make sure no leaks exist before adjusting the
1-800-333-4000 (814-443-4881).
pressure regulator. by using a certified leak detection solution
such as Snoop
®
or equivalent (must not contain ethylene gly-
col).
CAUTION: Do not apply leak test solution to any part
of the rotary valve or the main PC Board assembly.
A malfunction in the pressure regulator will cause either a loss
or fluctuation in the oxygen flow which will be seen on the
flow meter or a decrease in oxygen concentration.
To replace the pressure regulator (Figure 9):
1. Make sure the unit is unplugged from the wall outlet.
2. Remove the front and back cabinets.
3. Remove the tubing clamp and tubing from the pressure regulator.
4. Unscrew the regulator from the accumulator tank.
5. Install a new regulator on the accumulator tank and attach the
tubing and tubing clamp.
6. Replace the front and back cabinets.
PRINTED CIRCUIT BOARD
The printed circuit (PC) board is responsible for monitoring
and controlling the DeVilbiss Oxygen Concentrator.
The PC board has preset alarms for low flow and power failure. Should any of the alarm values be exceeded, the patient
alert system will activate.
NOTE: If the concentrator has been unused for an extended
period, the unit must run 20 minutes before the power fail
alarm will be enabled.
This alarm is powered by a capacitor on
the PC board.
UTION: Do not apply any force or flex to the PC
CA
Board when connecting or disconnecting electronic or
pneumatic components. Damage to the electronic
assemb
ly is possible.
To remove and replace the PC board (Figure 7):
1. Make sure the unit is unplugged from the wall outlet.
2. Remove the front and back cabinets and the bib.
terminals and connectors.
3. Disconnect all wir
4. Remove the 1/8" (3.2mm) tubing attached to the sensor.
e the screw that secures the board to the unit and
v
Remo
5.
e the PC boar
v
emo
r
6. Install the new PC board and secure it using the screw.
Reconnect all electrical wir
7.
tubing to the sensor
8. Replace the bib and front and back cabinets.
es ,
d.
terminals,
es,
connectors and the
.
ROTARY VALVE (Figure 13)
The timed rotary valve alternately distributes pressure supplied by the compressor to the sieve beds.While one bed is
eing pressurized the other bed is being exhausted through
b
the valve. Exhaust gases go through the valve exhaust port and
exit through the exhaust muffler.
The valve contains two revolving discs powered by a stepper
motor to cycle the pressure between the beds.DC voltage is
supplied by the PC board to the motor windings causing the
internal discs to turn and direct pressure to the proper sieve bed.
If the rotary valve does not shift properly the same bed may
ontinue to pressurize causing the pressure relief valve to
c
release the excess pressure.
There are several reasons why the rotary valve could malfunction; therefore the cause of failure must be determined before
corrective action can be taken.
To test the rotary valve (Figures 6 & 7):
1. Remove the front cabinet.
2. Connect pressure gauges to the test points at the top of the
sieve beds in order to observe unit cycling and bed pressures.
Refer to the section on
3. If it is determined that the valve did not shift properly or the
bed pressures are uneven, continue testing with step 4.
4. The stepper motor on the rotary valve has multiple windings
so there are several voltage readings that need to be checked
in order to determine if the problem is being caused by the
PC board or the valve itself.Testing for proper voltage is done
at the wire harness connectors on the valve or on the PC
Board using a voltmeter. Below are the valve voltage test positions and voltages that should be present at each one:
Negative LeadPositive LeadVoltage Reading
OrangeYellow or White12 VDC
OrangeGra
OrangeBrown5 VDC
Black or Green or
Red or Blue
TE:
NO
The 2-3
cycles. 515A Series have a fixed cycle time of approximately 7
seconds. However, when the ADS model (with OSD) goes into
“turn-do
its
wn” mode, the cycle time is shortened to approxi-
mately 3 seconds.
If any of these r
5.
en wir
brok
eadings ar
es in the harness.
main PC board.
6. If proper voltages are obtained, replace valve.
eplace the r
o r
T
1. Make sure the unit is unplugged from the wall outlet.
ont cabinet and loosen the bib
e the fr
v
Remo
2.
Unplug valv
3.
e wir
Normal Operating Sequence.
y
5
VDC
(intermittent)
Yellow or White2-3 VDC
olt reading will go on and off as the valve
V
e not obtained, check for loose or
replace the
,
otar
y valv
e harness is okay
If wir
e:
.
e harness fr
om the valve.
19
LT-1928
COMPONENT TESTING, REPAIR, AND REPLACEMENT
4. Cut plastic cable ties on sieve bed hoses.
. Loosen speedy clamps and remove bed hoses from each side
5
of valve.
. Loosen ladder clamps and remove pressure intake and exhaust
6
hoses from backside of valve.
7. Replace foam dampers, if necessary, with ones included in new
alve package.
v
8. Install the new rotary valve by reversing the above procedure.
NOTE: Use minimal force when tightening the cable ties
around the rotary valve. Overtightening the cable ties can
transmit sound to the cabinet, increasing noise level.
SIEVE BED CHECK VALVES
A check valve (Figure 9) located between the outlet of each
sieve bed and the accumulator tank allows oxygen to pass
through the sieve beds to the accumulator tank when the bed
pressure is greater than the accumulator tank pressure. These
valves also prevent reverse flow of oxygen from the accumulator to the sieve beds.
Run the accumulator pressure test described in the
Testing, Repair, and Replacement
section. It covers details of
Component
attaching the gauge.Acceptable pressure swing ranges at various altitudes are included in the
Specifications.
A defective check valve will result in a decrease in oxygen concentration and lower accumulator pressures.
To replace a defective check valve, remove the tubing on
either side of it and install a new valve making sure the outlet
end is toward the accumulator tank.
LT-1928
20
FIGURES, DIAGRAMS, AND VIEWS
FIGURES, DIAGRAMS, AND VIEWS INDEX
Exterior Views
he following figures show the exterior of the DeVilbiss 5-Liter Series Concentrators.