Page 1 of 19 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.
Page 2 of 19 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)
Note: do not touch flow regulator Page 3 of 19
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Page 5 of 19 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.
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 Page 6 of 19
Page 7 of 19 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
Page 8 of 19 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
Page 9 of 19 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
Page 10 of 19 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.
Page 11 of 19 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
Page 12 of 19 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
Page 13 of 19 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
Page 14 of 19 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
Page 15 of 19 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
Page 16 of 19 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)
Page 17 of 19 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
Page 18 of 19 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
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 Page 19 of 19