oxygen concentrator procedure - wild apricot. caution: avoid fans on motor and center of machine....

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Oxygen Concentrator Procedure

Section 1: Investigating Normal Operation

Section 2: Determining Cause of Malfunction

Appendices

A: Using an oxygen sensor

B: Using a pressure gauge

C: Using a multimeter

Warnings

Always use proper size and shape of screw driver

Note: screws attached to vibrating components might turn in opposite

direction.

STOP if screwdriver turns and screw does not. Screw will strip and be

unusable.

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Section 1: Investigating Normal Operation

In this section you will observe and familiarize yourself with the operation of a working oxygen

concentrator in order to better locate broken parts of malfunctioning machines.

Getting started

a. Concentrator Specific Safety a. DO NOT CREATE SPARKS, SMOKE, OR IGNITE FLAMES NEAR OXYGEN

CONCENTRATORS. High concentrations of oxygen will be leaked into the air. b. Gather necessary tools

a. Operation and/or service manuals b. Screwdriver set c. Oxygen sensor (Appendix B) d. Flow meter (Appendix A) e. Pressure Gauge (Appendix C) f. Press Gauge Connectors (Female ¼” Thread x 1/8” ID) g. Adjustable wenches h. Multimeter

c. Find and Identify Major Components Shown in Pictures Below (unplug machine and

remove outside covers)

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Note: do not touch flow regulator

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Note: you will not be able to access this part of the concentrator. Make sure you can

recognize the parts in the following two pictures.

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Step 1: Overall Function

In this step you will determine if the device release a flow of air when turned on.

a. Replace all covers

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b. Plug in machine

c. Turn on Oxygen Concentrator

d. Set both flow rates to 5LMP

a. Note: measuring ball must sit ON TOP of desired LPM

e. Make sure:

a. Alarm sounds for roughly 5 seconds (no longer)

b. Machine makes reasonable amounts of noise and vibrations

c. Air can be felt coming out of both outlets

Step 2: Checking Flow Rate

In this step you will determine if the flow rate readings are calibrated correctly.

a. Set up flow meter a. Attach barbed output attachment to oxygen output b. Connect tubing to barbed output attachment c. Ensure other end of tubing is attached to bottom of flowmeter d. Read flowmeter in the middle of the ball e. Note: 0.472LPM=1SCFH

b. Plug in machine c. Turn on concentrator d. Set both flow rates to 2LPM (4.2 SCFH)

a. Note: measuring ball must sit in the middle of desired LPM

b. Ensure set LPM matches meter reading (±1LPM)

c. Repeat for other oxygen output

e. Repeat for 5LPM (10.6 SCFH) and 10LPM (21.2 SCFH)

Step 3: Checking the system pressure

In this step you will determine if the pressure of the pneumatic system is within the correct

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range. The black tubing will test the pressure of the canisters. The blue tubing will test the

pressure of the air from the compressor.

a. Turn concentrator off

b. Depressurize machine

a. Set both flow rates to maximum

b. Wait for air to stop flowing from concentrator

c. Remove right side panel

d. Locate ¼ in black pressure tubing

a. Remove tie and stopper from end of tubing

b. Connect pressure gauge to black tube

c. Turn machine on and allow it to run for 5 minutes

i. CAUTION: AVOID FANS ON MOTOR AND CENTER OF MACHINE. FANS

CAN CAUSE SEVERE INJURY.

d. Note minimum and maximum pressures after concentrator has been on for 5

minutes. Ensure:

i. Min~0.175MPa

ii. Max~ 0.220 MPa

e. turn off machine (do not disconnect pressure gauge yet)

f. depressurize

i. set both flow rates to maximum

ii. wait for air to stop flowing from concentrator

g. disconnect pressure gauge

h. replace stopper and tie at end of tubing

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e. Locate blue pressure tubing (near black pressure tubing)

a. Remove tie from end of tubing

b. Connect pressure gauge to blue tube

c. Turn machine on and allow to run for 5 minutes

i. CAUTION: AVOID FANS ON MOTOR AND CENTER OF MACHINE. FANS

CAN CAUSE SEVERE INJURY

d. Ensure maximum pressure reaches 0.047‐0.53MPa

e. Turn off machine (do not disconnect pressure gauge yet)

f. Depressurize

i. set both flow rates to maximum

ii. wait for air to stop flowing from concentrator

g. disconnect pressure gauge

h. Replace tie at end of tubing

f. Replace outer covers on concentrator

Step 4: Checking Oxygen Concentration

In this step you will determine if the concentrator is producing sufficiently concentrated oxygen

which will indicate if there are additional problems with the device.

a. Plug in machine

b. Turn on Concentrator

a. Note: machine takes a while to reach full oxygen potential

c. Set left flow rate to 5LPM, set right flow rate to 0LPM

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a. Attach sensor to oxygen output

b. Ensure concentration is close to 95% (above 85% is acceptable)

d. Set left flow rate to 0LPM, set right flow rate to 5LMP

a. Repeat sensor measurement

Step 5: Checking the Filters and Muffler

In this step you will determine if the filters and mufflers are a cause of low flow rates or low

oxygen concentrations.

a. Ensure filters are free of debris and don’t appear discolored

a. Gross particle filter on back cover

b. Air intake filter

c. Air Exhaust filter (you will not be able to check this, but note that there is

another filter)

b. Muffler (you will not be able to check this but not that there is a muffler on the exhaust

to prevent noise)

Step 6: Checking Power Failure Alarm

In this step you will determine if the power failure alarm functions when the device is not

plugged in.

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a. Battery

a. Plug in machine

b. Turn machine ON

c. Ensure:

i. Alarm sounds for 5 seconds

d. Turn machine OFF

e. Open machine’s shell

i. Remove Alarm Battery

ii. Test electrical connection from On/Off Switch to battery

Step 7: Checking Electrical Connections

a. External power is reaching machine

a. Inspect power cord for wire damage

b. Ensure circuit breaker is set correctly

a. Pushed in all the way

c. Circuit boards and wires

a. Circuit Boards

i. Power distribution board

ii. Power distribution board for fan

iii. Board containing oxygen sensor

b. Wires

i. All visible and accessible wires

c. Note connectivity of components on all circuit boards and connecting wires for

later comparison in section 2

i. Resistors over ~100 ohms should not be continuous

ii. Resistors under ~100 ohms should be continuous

iii. Capacitors should not be continuous

iv. Diodes should not be continuous

v. Bridge rectifiers should not be continuous

vi. Wires should be continuous

d. Pay special attention to oxygen and pressure sensors

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i. Oxygen Sensor

ii. Pressure sensor

d. High Capacitance Capacitor

a. Directly above motor

b. IMPORTANT: if you unplug the capacitor you MUST discharge it

c. Test connections of wires connected to capacitor

Step 8: Checking Solenoids

In this step you will determine if the valves are opening and closing at the appropriate times.

a. Plug in machine

b. Open shell

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a. CAUTION: AVOID FANS ON MOTOR AND CENTER OF MACHINE. FANS CAN

CAUSE SEVERE INJURY.

c. Turn machine on

d. Observe five LEDs on power distribution board

a. Make sure at least 2 LEDs are active at all times

b. Note:

i. If any LEDs do not light up

ii. Which LED(s) is lit if abnormal noise is heard

e. TURN OFF and UNPLUG the machine

f. Depressurize

a. set both flow rates to maximum

b. wait for air to stop flowing from concentrator

g. Check resistance of each solenoid

a. Equalization Valve Solenoid: ~1000‐1100 ohms

b. Four in the four‐way valve: ~838 ohms

Step 9: Checking Tubing

In this step you will determine if the tubing is secure and not the cause of improper flow rate or

oxygen concentrations.

a. Unplug machine

a. Check for visible damage to tubing and connections

b. Plug in machine

c. Open shell

c. CAUTION: AVOID FANS ON MOTOR AND CENTER OF MACHINE. FANS CAN

CAUSE SEVERE INJURY.

d. Turn machine ON

a. Listen for leaks in tubing or connections

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Step 10: Checking the motor

In this step you view pictures of the motor and area behind the motor. We will not remove the

motor because of the fragility of its connections.

Motor

Inside of motor

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Behind motor

a. Check power connection to motor

a. Wires going to and from motor

Step 11: Close and Test

In this step you will put the device back together and test to make sure it’s functions are normal.

a. Close shell

b. Retest oxygen concentration

c. Retest flow rate

d. Retest Alarm

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Section 2: Determining Cause of Malfunction

In this section you will troubleshoot and fix malfunctioning devices. Using what was collected from

Section 1 and the 5 steps of troubleshooting, determine the damaged part(s) of the device. You will

rotate between three machines with different problems.

Instructions:

Read background of the device

Go through 5 steps of troubleshooting

Locate damaged part(s)

Confirm choice with TA

Replace damaged part(s)

Reconnect machine

Check overall function (step 1)

Check flow rate (step 2)

Check oxygen concentration (step 3)

Appendix

A. Using an oxygen sensor

a. Calibrate the sensor

i. Turn the sensor on

b. Connected flow diverter (white piece) to top of T adaptor

c. Connect sensor to flow diverter

d. Wait for sensor to equilibrate

e. With nothing connected to the senor press and hold the calibration button (downward

arrow)

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f. Place smaller side of tube against O2 output

g. Wait for meter to equilibrate

B. Using a Pressure Gauge

a. Buttons

i. “ON/UNIT/OFF” Button

1. Press to turn on

2. Press to change units

3. Hold to turn off

ii. LIGHT/P‐H Button

1. Press for backlight

2. Hold to see maximum pressure gauge has been exposed to

a. Numbers will blink in this setting

iii. RESET/CLEAR Button

1. Hold to calibrate the current pressure to 0

b. Use

i. Hold down RESET/CLEAR button to calibrate

ii. Connect appropriate tube adapter to gauge’s port

iii. Connect tubing end of adapter to tube

iv. Turn gauge on

C. Using a Multimeter

a. To test connectivity

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i. Set dial to alarm setting

ii. Meter will beep if circuit is complete

iii. Test by touching the red and black probes together

b. To test voltage

i. Set meter to AC or DC setting

ii. Touch probes to opposite sides of voltage being tested

c. To test Resistance

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i. Set meter to ohms

ii. Touch probes to either side of capacitance being measured

iii. Note the units if applicable

D. Using a screwdriver

a. Make sure the correct size is being used

b. Apply ample pressure onto the screw

c. Turn counterclockwise to loosen

d. Turn clockwise to tighten

i. Note: screws attached to vibrating components might turn opposite

e. STOP if screw driver turns and screw DOES NOT

i. Screw will strip and be unusable

oxygen concentrator procedure - wild apricot. caution: avoid fans on motor and center of machine....

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