Session 8

COVID-19 Preparation for Biomedical Professionals

Oxygen Concentrators: Part 2

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AgendaTime Allotted Topic Presenter

30 minutes Didactic – Oxygen Concentrator Egr. Gunalan Dass

20 minutes Case Study Presentations – Ethiopia

Wendemu Zeyede,

Obsera Bulto, Meba

Hailu, Ashebir

Worku, Dr.

Masreshaw

Demelash

15 minutes Discussion

Oxygen ConcentratorsOxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Nasal Prongs

• Oxygen cannulae are plastic tubes shaped as two

prongs delivering an air/oxygen mixture into the

nasal cavities. This device is connected with an

oxygen administration circuit.

• Cannulae can be designed for low-flow

applications (0–15 L/min range in general) or high

flow (> 15 L/min typically). Oxygen and air/oxygen

mixture compatibility, is per ISO 15001.

• Different sizes: adult, pediatric, neonatal

• Single use

Pressure Swing Absorption

Oxygen concentrators use a material called “molecular sieve” that

absorbs nitrogen from the air.

• More pressure = more nitrogen absorbed

The amount of nitrogen that the molecular sieve can absorb is

dependent on the pressure of the gas.

Air consists of approximately 79% nitrogen and 21% oxygen.

• Two feed valves allow air to enter each of the two sieve beds.

• Two waste valves allow waste to exit each of two sieve beds into the atmosphere.

• One equalization valve allows gas to flow from one sieve bed to the other.

Five solenoid valves control the flow of gas through the device:

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Pressure Swing Absorption (PSA)Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Block Diagram

• Intake filter can be

washed and reused.

Worn filters may need to

be replaced.

Cleaning/replacing the

intake filter should be

done during every single

service.

• Product filter needs to be

replaced every 10,000

hours depending on

manufacture

recommendation.

• Clean inside to prevent

dust build up.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Air Intake Filter and Product Filter

• Air intake filter:

• Washed and reused during every service.

• Some are single use (work more than 15,000

hours).

• Depends on condition and manufacture

recommendation.

• Product filter is replaced every 10,000 hours.

• Please refer to Hour Counter on the oxygen

concentrator.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Important Components

• Equalization valve allows gas to flow from one sieve bed to the other and vice versa.

• Control board and power supply

• Sieve tank 1 and 2

• High Pressure Valve:

• 2 feed valves allow air to enter each of two sieve beds.

• 2 waste valves allow waste to exit each of two sieve beds to the atmosphere.

• Some units use only 2 valves: feed and waste are built like a two-way switching valve.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Sieve Bed

• A sieve bed is the filter inside the oxygen concentrator which

separates out the nitrogen from the oxygen in the air. This filter uses

a material, zeolite, to collect all the nitrogen in the air.

• Typically, a concentrator has two of these sieve beds with one of

them always working to collect nitrogen and the other is removing

extra nitrogen that has already been collected. The two sieve beds

switch jobs every few minutes automatically, in a sustainable,

ongoing process.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Common Problems

The sieve tanks are filled with zeolite granules, a synthetic aluminium silicate. Zeolite acts as a molecular sieve which binds the nitrogen molecules and lets the smaller oxygen molecules pass.

• Sieve tanks should last at least 20,000 hours, and when regularly maintained even 40,000 hours or more.

• To determine the hours of operation please refer to the hour counter.

• Sieve tanks tend to lose their filter properties over time. High humidity is often the reason.

• Water then condenses inside the filter and clogs the granules. Excessively high system pressure and low oxygen concentration is an indicator for a blocked filter.

• One sieve tank will deliver more oxygen than the others as the control circuit periodically switches between them when testing.

• A clogged sieve which contains water weighs more.

*Note: price for zeolite USD 8/Kg 13

XHP

USD 34/Kg (Lithium based) not included

shipping cost.

Sieve Bed Repours

Replacement Overview:

All gaskets and filters are replaced.

Replace the 8cm O-ring during this

process.

The product filter (bacteria filter) should be

replaced every 10,000 hours of use.

The canisters are refilled with new zeolite

material.

The exterior of the canister is cleaned, and

any old labels are removed.

The repoured sieve beds are pressure

tested at 45 psi then monitored in-use on a

concentrator to ensure no leakage and

high oxygen purity.

Leaks can be so small that oxygen

concentration may not be affected

immediately. Also, the sieve material can

become contaminated gradually.

**Careful leak testing is important.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Absorption Bed Assembly

(Sieve Tank)Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Brand Size Shape

AIRSEP

40cm Long X

8cm

Diameter

Cylinder

DEVILBISS/

Some China

made

44cm Long X

8cm

Diameter

Cylinder

DEVILBISS

32cm Long X

8cm

Diameter

Cylinder

Sieve Bed Repours and Replacement

1. Open the sieve tank carefully.

2. Remove the zeolite and clean the tank.

3. Replace the old O-ring on both sides with new ones.

4. The canisters are refilled with a new zeolite material.

Each tank needs almost 2.3 kg of new zeolite.

5. Reassemble the sieve tank and confirm that the top

cap and bottom cap are sealed properly with a new

O-ring before doing the pressure leak test.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Absorption Bed Disassembly(Sieve Tank)

Carefully remove the spring,

moving piston, and barrier paper.

Make sure to not cause any

damage to the barrier paper.

Open the top part of the sieve tank

carefully by removing the nut (use

safety goggles and other PPE).

Secure the nut located at the

bottom cap. Be sure to push

down tightly on the cap to

prevent the spring from moving.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Absorption Bed Disassembly (Sieve Tank)

Please check all the baffle and

stationary piston are in excellent

condition.

Please check for any damage and replace the O ring on both sides

of the tank.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Absorption Bed Disassembly (Sieve Tank)

Please remove the old zeolite into a dry container

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Sieve Bed Repours and Replacement

6. Use an air compressor to set at 40 to 45psi check by

using DPM 4 pressure meter the range is in 40 to 45

psi than connect to the bottom part of the cylinder

make sure no leak.

7. Connect DPM 4 on top of the cylinder.

8. Then pressure the cylinder for 20 sec see if the reading

of DPM has to be in the range 40 to 45 psi test for 20

sec see how much the pressure drop from the actual

measurement value tolerance is ± 4.5 psi.

9. Check using oxygen analyzer; a good installation

reading will be somewhere 87% to 95%.

40 to 45 psi compressor air

Connect DPM 4

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Sieve Bed Repours and Replacement

10. Make sure the pressure test is

pass, and after that, please use

Oxygen concentrator to test

oxygen output.

11. Please install the sieve tank back

to oxygen concentrator and

check if the high pressure and

low-pressure circuit inside the

range.

12. Then check the oxygen purity

output is supposed to be in 95 to

87% oxygen depends on the

flow setting on the oxygen

concentrator.

Bottom

Top

Block one side of

this line.

Connect DPM 4 for

pressure test.Connect the 45

psi pressure line.

DPM 4

40 TO 45 PSI

40 TO 45 PSI

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Size & Shape of Sieve Tank:

Brand Size Shape

AIRSEP 40cm Long X 8cm Diameter Cylinder

DEVILBISS/ Some china made 44cm Long X 8cm Diameter Cylinder

DEVILBISS 32cm Long X 8cm Diameter Cylinder

Each sieve tank need about 2.3kg to 2.5kg depends on model and brand.

Test tools required for testing:

• Digital pressure meter (DPM)2G

• Oxygen analyzer

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Pricing for Zeolite or Molecular Sieve

There are a few types of zeolite in the market and this item is not under a

dangerous goods list:

• 13 XHP Molecular sieve is about 8 to 12 USD/Kg

• Lithium based molecular is 34 to 38 USD/kg

• Logistic extra charges

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Overview:

Pressures & Switching Times

Complete cycle: 15 - 18 seconds

Pressure patient outlet: 0.5 bar (8 psi) (>50kPa)

Equalization time: 1 – 2 seconds

Pressure reservoir tank: 1.4 - 2.0 bar (20 - 30 psi) ( <220 kPa)

Half cycle (filtering or flushing): 7 - 8 seconds

Pressure compressor: 1.4 - 2.0 bar (20 - 30 psi) ( <220 kPa)

Pressure relief valve 50 psi at the compressor

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Safety Issues To Consider:

Detrimental Health Effects:

• Only effects are associated with inhaling the

finely ground powdered material in the

area.

Handling Precautions:

• Breathing dust protection should be worn.

Emergency and First Aid Procedures:

• Move to open area with better air

ventilation, resuscitate, if necessary.

Steps for Material Spills:

• No toxic effects. Clean up and recover as

suitable.

Waste Disposal Method:

• Spills on the ground should be cleaned up

in a manner which does not generate dust.

Dispose of in a landfill or distribute thinly

over any suitable cultivable land.

Protective Gloves:

• Not necessary but useful since powder is oil

absorbent and drying.

Eye Protection:

• Safety glasses or goggles are necessary to

prevent dust from entering eyes.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Common Alarms

SYMPTOM: PROBLEM: SOLUTION:

Alarm:

• Short beeps

• Long pause

• Concentrator not operating,

power switch On.

• Ex. Beep......Beep......

Main Power Loss:

1. Power cord not plugged in.

2. No power at outlet.

3. Tripped circuit breaker.

4. Power compressor is not

working.

1. Insert plug into outlet.

2. Inspect house circuit breakers

or fuses. If problem reoccurs,

use a different outlet.

3. Check the compressor.

4. Unit has run too long, may be

thermal. Turn off to cool down.

Alarm:

• Continuous beep

• Concentrator not operating,

power Switch On.

• Ex. Beeeeeeeep....

System Failure:

1. Unit overheating due to

blocked air intake.

2. Insufficient power at outlet.

3. Internal repairs required.

1. Remove and clean cabinet

filters.

2. Move oxygen concentrator at

least three inches away from

walls, draperies or furniture.

3. DO NOT use extension cords.

Move to another electrical

outlet or circuit.

Alarm:

• Rapid Beep

• Ex. Beep... Beep...Beep

Low Flow Alarm:

1. Kinked or blocked tubing,

cannula or humidifier.

2. Flowmeter set at 0.5 L/min or

less.

1. Inspect for kinks or blockages.

2. Correct, clean or replace item.

3. Once corrected, turn power Off

for 60 seconds and then turn

power back ON.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Common Alarms

SYMPTOM: PROBLEM CAUSE: SOLUTION:

Alarm: YELLOW or RED light

Illuminated

Alarm: Continuous On RED light

only

1. Low oxygen purity.*

2. Kinked or blocked tubing,

cannula or humidifier.*

3. Flowmeter set at 0.5 L/min or

less.

4. Unit overheating due to

blocked air intake.

* Depends on brand

1. Clean or replace filters.

2. Inspect for kinks or blockages.

Correct, clean or replace item.

Once corrected, turn power Off

for 60 seconds and then turn

power back On.

3. Check flowmeter is set to 1.0

L/min or more.

4. Remove and clean cabinet

filters.

5. Move concentrator at least

three inches from walls,

draperies, and furniture.

Troubleshooting

As always, troubleshooting starts with observing and listening to

the machine.

✓ Complete a function check.

✓ Listen for any abnormal sounds and check the switching times.

✓ If anything sounds abnormal, open the concentrator and have a closer look.

Often the status of the valves is indicated by LEDs which are mounted on

the control board (depending on the model). Certain concentrator models

have ports where you connect a pressure gauge.

✓ Consult the service manual.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Troubleshooting

The unit runs but a low pressure, low 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.

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.

4. If filters are clean and there are no leaks, then the compressor is defective. 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 equalization

valve is not operating correctly.

6. If the unit is cycling in conjunction with very high bed pressures, this indicates defective

sieve beds.

Troubleshooting

The compressor will not start when the unit is

turned on.

Verify that the cooling fan is running; if it is not, determine where you are losing power.1

4 If voltage is not present, the wire harness is defective.

2 Check for compressor voltage at the compressor connector.

3 If voltage is present, then the capacitor or compressor is defective.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Troubleshooting

sieve beds

flow meter

accumulator tank/Product tank

final bacteria filter

pressure regulator

final check valve

outlet port

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.

Do not apply leak test solution to any part of the

valve or the main PC Board assembly.

The concentrator runs and continues

to cycle but has low oxygen

concentrations.

Check for oxygen leaks at:

Connect test gauges and check for higher or

lower than normal bed pressures.

a) High pressures indicate defective sieve

beds.

b) Low pressures indicate occluded filters,

leaks, or defective compressor.

c) Uneven bed pressures indicate valve is not

operating correctly.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Experience Sharing on Oxygen Concentrator Maintenance

Addis Ababa Tegbare-id Polytechnic College

Biomedical Technology Department, 2020

COVID-19 Medical Equipment Maintenance

Maintenance Workflow Chart

FAIL

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

✓ Acceptance

✓ Maintenance

✓ Test & Analysis

✓ Decommissioning

DocumentationOxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Covid-19 Medical Equipment Acceptance Checklist

Addis Ababa Tegbare-id Polytechnic College

Biomedical Technology Department, 2020

Equipment Details

Asset #*: Model:

Hospital Name: Serial number:

Equipment Name: Manufacture:

Accessories

History/ Status

Ow ners information

Name: e-mail:

Signature: Phone #:

Date of arrival:

*Asset #: First tw o letter of hospital (abbreviation of hospital), number of equipment

based on registration

DocumentationOxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

PPE

Disassemble

Cleaning

Disinfection

Air Dry

Decontamination Procedure

(Safety First!)Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Troubleshooting StepsOxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Troubleshooting any system requires

an understanding of:

How it operates?

How it does it?

What it does?

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Always Remember KISS

(Keep It Simple, Stupid)

“When faced with two possible

explanations, the simpler of the

two is the most likely to be true”

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Case Study:

Yuyue Oxygen ConcentratorNote: The error codes discussed in this case study is specific to the Yuyue

oxygen concentrator. Please consult the technical reference manual of your

specific oxygen concentrators for description of error codes.

• Common failure

• Machine stops running after a few hours/minutes

• Low oxygen concentration output

• Oxygen delivery at low pressure/high pressure

• Machine stops running

• Machine runs but no gas output

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Case Study

Case 1: Machine stops running after a few hours/minutes

Problem

• Pressure/O2 concentration sensor senses above or below operating range

• Dust on PCB board or oxygen sensor board and dust particle block air ways

Solution• Clean dust particles and check the output pressure and O2 concentration

E1 or E2 or LO- error message displayed on the screen on some brands

Case Study

Case 2: Low oxygen concentration output

Problem

• Dirty filter and dirt tube

• Cracked or kinked pneumatic tube

• Zeolite expired (20,000hr)

Solution

• Clean filter and tube

• Replace zeolite

• Correct the tube if kinked and change the

tube

L0 (low O2 concentration)- Error message is displayed on the screen in some brands

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Case Study

Case 3a: Oxygen delivery at low pressure

Problem causing low pressure:

• Blocked tube and dirty canister intake

/inlet/gross/ filter

• Leakage

• Pressure regulator adjusted at low level

• Low air compression

Solution

• Check the tube to see if it is blocked

• Clean the filter

• Check the tube for cracks and tighten the

tube if it is loose

• Adjust the pressure to the correct range

E1 (low output pressure )- error message

displayed on screen in some brands

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Case Study

Case 3b: Oxygen delivery at high pressure

Problem causing high pressure

• Narrowed tube diameter due to dust particles

• Pressure regulator adjusted at a high level

Solution

• Clean the dust particles

• Adjust the regulator to normal operating range

E2 (high output pressure)- error message

is displayed on the screen in some brands

Error code E2

Pressure measurement:

96kpa

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Case Study

Case 4: Machine does not function when

switched on

Problem

• Electrical wire disconnections

• Starting capacitor failure

• Compressor failure

• Electrical component failure

Solution

• Check electrical connection

• Check and replace capacitor

• Check motor winding and replace if

necessary

• Check other circuit components such as

transformer, fuse, etc.

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Audible alarm gives sound continuously if

machine is turned on and AC power cord

unplugged.

Case Study

Case 5: No gas output when the

machine is turned on

Problem

• Blocked check valve/failed solenoid coil

• Disconnected tube or leakage

• Blocked HEPA filter/ inlet filter

Solution

• Check solenoid valve and replace if

necessary

• Check disconnected tube/leakage and

tighten the connection

• Clean/replace HEPA/intake/gross filter

E3 (open compressor/open air way)- error

message is displayed on the screen in some

brands

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion

ContributorsGunalan Dass, Assist International

Benjin Joshua, Assist International

Erin Sharkey, Assist International

Dr. Masreshaw Demelash, Assist International

Ashebir Worku, AATPCWendemu Zeyede, AATPC

Obsera Bulto, AATPC

Meba Hailu, AATPC

Oxygen

Concentrators

Overview

Filters,

Cannulae, &

Other

Components

Sieve Bed

Repours &

Replacement

Common

Alarms

Troubleshooting

Maintenance

Case Studies

Discussion