TECHNICAL MANUAL RESPIRATORY HUMIDIFIERS MODELS: MR730 MR720 MR700 MR480 Revision F Issued March 2001 Fisher & Paykel Healthcare Ltd Auckland, New Zealand
ii National Office: Fisher & Paykel Healthcare Ltd P.O. Box 14348, Panmure Auckland, New Zealand Telephone: Facsimile: +64-9-574 0100 +64-9-574 0158 Technical Manual for Respiratory Humidifier MR730 Dual Servo MR720 Dual Servo (anaesthesia) MR700 Dual Servo MR480 Single Servo Fisher & Paykel Healthcare have a policy of continued product improvement and reserve the right to alter specifications without notice. Revision F changes, Section Description of Change 6.0 7.33 8.10 9.
iii CONTENTS PAGE 1.0 MR700 SERIES GENERAL SPECIFICATIONS ................................................................................1 1.1 Electrical Specifications ................................................................................................................................................................1 1.1.1 Models MR730/720/700...................................................................................................................................................
iv 4.0 CIRCUIT OPERATION .........................................................................................................................9 4.1 Introduction......................................................................................................................................................................................9 4.2 Control Board...............................................................................................................................................
v 8.0 SCHEMATICS, PART LISTS AND MECHANICAL DRAWINGS ................................................20 8.1 MR700 Series Circuit Layout Block Diagram ...................................................................................................................... 20 8.2 Component Layout - Revision H and J PCB............................................................................................................................. 21 8.3 Component Layout - Revision F PCB ........................
vi C.1.2 C.1.3 C.1.4 C1.5 C1.6 C1.7 C1.8 C1.9 C1.10 C2 High Temperature........................................................................................................................................................... 51 Temperature Fluctuating............................................................................................................................................... 51 Excessive Water In Circuit ...................................................................................
1 1.0 MR700 S ERIES GENERAL SPECIFICATIONS _________________________ This documentation defines the technical specifications of the MR730, MR720, MR700 and MR480 respiratory humidifiers, it also includes maintenance and repair procedures. The MR730/720 models are Heated Wire humidifiers with the option of disabling the Heater Wire. The MR720 has a lower alarm limit and an extended warmup mode for use in Anaesthesia. The MR700 model is exclusively a Heated Wire humidifier.
2 1.5 T EMPERATURE DISPLAY Three digit 14mm 7 segment LED (Light Emitting Diode) display. Range 5.0 to 80.0 °C. Below 5.0 °C displays ‘Lo’. Above 80.0 °C displays ‘Hi’. Accuracy 25.0 ± 0.3 °C to 45.0 ± 0.3 °C. 1.6 GLOSSARY OF ABBREVIATIONS EOH The End Of Hose temperature. OFFSET The temperature difference of the TOP from the SET. SET The temperature Set potentiometer. Sets the controlling temperature of the EOH. TOP The temperature at the Top of the humidification chamber. RSD Remote Shut Down. Ref.
3 2.0 OPERATING CONTROLS AND M ODES _____________________________ 2.1 ADJUSTABLE CONTROLS 2.1.1 AIRWAY TEMPERATURE CONTROL Selects the airway controlling temperature. The range of adjustment is from 31 to 40 °C over a linear scale marked in degrees on the front panel. The temperature can be set with a resolution of 0.1 °C. The set temperature is flashed on the display when the control knob is rotated and continues to be flashed for five seconds after the last adjustment. 2.1.
4 2.2.3 STANDBY BUTTON (MR700/720/730 ONLY) This button has to be depressed for one second to enter or exit the standby mode. When the adjacent amber LED starts to flash (100/minute) the button can then be released and the Humidifier remains in the standby mode. To exit Standby mode press the Standby button for 1 second, the amber LED will then turn off. An audio beep accompanies a change in the Standby mode state. 2.2.
5 2.6 WARM UP M ODE After initial turn on, warm up mode is entered. In this mode the Low temperature alarm is disabled. The Low temperature alarm is enabled when warm up mode is exited. 2.6.1 W ARM UP MODE EXITING CONDITIONS (LOW TEMPERATURE ALARM ENABLED): • (MR700/MR730(All versions) and MR720(version 1.0) in Heater Wire Mode) Warm Up mode continues until the Software DetectsEither: The airway temperature reaches within 0.8 °C of the Temperature Control set point.
6 3.0 ALARMS AND INDICATORS _____________________________________ 3.1 T EMPERATURE PROBE ALARM If the airway temperature probe is disconnected or develops a low or high resistance the Temperature Probe alarm will be enabled. Indication is by a ‘- - -' message on the airway temperature display plus a flashing Temperature Probe red LED and an audio alarm. Five specific fault types can be diagnosed and are displayed by the sequence of ‘decimal points’ in the display, as shown below: a --- b - - -.
7 3.2.4 CHAMBER TEMP HIGH ALARM This alarm will activate if: • The temperature of gas leaving the humidification chamber outlet is more than 4 °C higher than the chamber set temperature for more than 20 minutes. (The chamber set temperature is the sum of the Temperature Control setting and the Chamber Control setting). • The temperature of the gas leaving the humidification chamber outlet exceeds the chamber set temperature by 10 °C or more.
8 Pushing the mute button mutes the audio alarm for ten minutes and restores power to the heaterplate during this time. The Airway Temp Low LED will continue to flash. This alarm is disabled during warmup. See § 2.6.2. If the airway temperature drops below 5°C the display will show ‘LO’ and an audible alarm will sound. 3.4 AUDIO ALARM A choice of the ISO draft standard audio alarm or a gliding tone can be selected by the programming control link (L1). Refer Appendix A3.
9 4.0 CIRCUIT OPERATION _________________________________________ 4.1 INTRODUCTION This section describes briefly the operation of each of the circuit sections. Refer to the circuit diagrams in § 8.5 to 8.8. 4.2 CONTROL BOARD The one basic control board, with various discreet hardware changes, provides the controlling functions for the MR730/720/700/480 range of humidifiers. Each model however is controlled by a unique software version. 4.2.
10 during calibration to give the desired ramp rate. Thus all points are scanned once every 500 to 600 ms, self calibration performed, and the digital display updated. 4.2.5 POWER LINE INTERRUPT (REVISIONS D/F PCBS) A sample of the power supply frequency is derived from the power transformer 22 Vac secondary via R56 and Q1, buffered by Schmitt trigger U5f and fed to the RST7.5 interrupt of U3.
11 4.3 POWER BOARD 4.3.1 REVISION D/F PCBS A bridge rectifier (D13 to D16) supplies power to the 5 V regulator Q7 mounted on the heat sink. This circuit is protected by a 1 A fuse (F1) mounted on the circuit board. The 5 V negative supply stabilized by Q8, is derived from the voltage doubling network D17, D18. The Heater Wire (HHC) is controlled by triac Q9 which is mounted on the heat sink. Q9 is switched by the optoisolator U11 which in turn is driven by Q10.
12 5.0 CALIBRATION______________________________________________ 5.1 INTRODUCTION Calibration should be performed after any servicing involving the printed circuit boards. After calibration, perform a performance check as outlined in § 6.0. Note: For instructions on disassembly of the unit, refer to § 7.0. Calibration is facilitated by entering a special Calibration mode. See Appendix A1.
13 1 Plug in the 41 °C calibration probe. 2 Gain access to the adjustment potentiometers VR4 and VR5, by removing the control board from the humidifier front panel. 3 With the Chamber Temp button held down turn on the power switch. Display should show -1- 4 Using the Chamber Temp button step through to number -4- 5 Starting with a vertical bar display adjust VR4 so the display changes to an all 8 display. If VR4 is rotated too far the display becomes all horizontal bars (||.||.||. thru 8.8.8.
14 6.0 PERFORMANCE CHECK_______________________________________ 6.1 INTRODUCTION This procedure should be used to check the operation and calibration of the MR730/720/700/480. This performance check should be performed after any servicing, and annually as part of the routine maintenance procedure (see Appendix B). Performance can be monitored during the test by using the functions of the Engineering Menu. See Appendix A2.
15 6.2.4 ALARMS CHECK MR700/720/730 1 Rotate Temperature Control knob to 37 and check for an Airway Temperature Low alarm. (For an MR720 set to 40 °C and check for an Airway Temperature Low alarm). 2 Rotate Temperature Control knob to 32 and check for an Airway Temperature High alarm. 3 If ‘set low’ light is not already on, rotate the chamber control to -1.5 and check that the ‘set low’ light comes on (all software versions).
16 6.3.4 6.4 ALARMS CHECK - MR480 1 Disconnect the 34.5°C temperature probe and check that the Temperature Probe LED flashes and gives an audio alarm. 2 Insert the 41°C temperature probe into the humidifier and check that the Airway Temperature High LED flashes and the audio alarm sounds. 3 Push the Mute button and check that the audio alarm is silenced 4 Go to the engineering menu and check that the heaterplate duty cycle (dc) is starting to decrease, this may take a few seconds.
17 7.0 SERVICING INFORMATION _____________________________________ 7.1 INTRODUCTION This section provides information for servicing the MR730/720/700/480 Humidifier. The electronic circuitry is contained on two separate circuit boards, the power board and control board. Please note the following: • Follow ESD precautions when handling circuit boards. • After replacing or modifying a circuit board, go through the calibration and performance tests outlined in § 5 and 6.
18 If you are fitting a Revision H or later power PCB to a Humidifier that has a revision F or earlier control PCB , you will have to ensure correct phase polarity on the transformer secondary wires. To check for correct polarity, turn the humidifier on, if the humidifier displays F-2, then the polarity of one of the transformer secondaries needs to be changed. This is accomplished as follows: i. Unplug the power supply and then unplug the transformer secondary connector (Connector J9) from the power PCB.
19 7.4.1 HEATERPLATES WITH SCREW -IN STANDOFFS For products after S/N:9773XXX19731, the heaterplate standoffs were changed to shoulder bolts that screwed directly into the heaterplate. When fitting these heaterplates,‘click’ the heaterplate springs into the recesses on the heaterplate (by rotating them while pushing down), then align the springs with the holes in the case front and screw in the self tapping standoffs into the heaterplate. 7.
20 8.0 SCHEMATICS, PART LISTS AND M ECHANICAL DRAWINGS________________ 8.1 MR700 SERIES CIRCUIT LAYOUT BLOCK DIAGRAM Ref.
21 8.2 COMPONENT LAYOUT - REVISION H AND J PCB Power Board Control Board Ref.
22 8.3 COMPONENT LAYOUT - REVISION F PCB Power Board Control Board Ref.
23 8.4 LINK PAD LOCATIONS FOR PROGRAMMING CONTROL OPTIONS - REVISION H AND J PCB Link Pads Control Board(viewed from solder side) Location of Link Pads for Programming Control Options (see Appendix A3) Ref.
24 THIS PAGE LEFT BLANK Ref.
25 8.5 CIRCUIT DIAGRAMS - REVISION H AND J PCB CONTROL PCB Ref.
26 8.6 CIRCUIT DIAGRAMS - REVISION H AND J PCB POWER PCB Ref.
27 8.7 CIRCUIT DIAGRAMS - REVISION F PCB CONTROL PCB Ref.
28 8.8 CIRCUIT DIAGRAMS - REVISION F PCB POWER PCB Ref.
29 8.9 ELECTRICAL PARTS LIST The electrical components listed below are referenced in accordance with the component layout and the circuit diagrams (see § 8.2 to 8.8). Note: The Control and Power PCB Assemblies listed below are replacement parts for Revision F & later PCBs. For replacement of Revision D PCBs refer to § 7.3 for details of upgrade kits. 8.9.1 CONTROL BOARD COMPONENTS: (REVISION H AND LATER PCBS) Ref Description Part No. Control PCB Assembly MR480 (No Eprom) ............................
30 R20 R21, R22, R23, R27, R29 R25, R35, R40 R30 R32, R63 R34 R37, R38 R42 Resistor 412E 0.25 W 0.5% Metal Film..................................................... 325040152 SW2, SW3, SW4 SW5 SPK1 Push Switch.................................................................................................. 349040094 Heater Wire Switch...................................................................................... 349040099 Audio Transducer CB-12KP ..................................................
31 8.9.2 POWER BOARD COMPONENTS: (REVISION H AND LATER PCBS) Reference Description Part Number Power PCB Assembly MR480 Complete.................................................. 043040678 Power PCB Assembly MR700/720/730 Complete ................................... 043040637 C6, C8, C32 C7, C33 C25, C27 C26 C28, C29 C30, C31 Cap. MKT. 100 nF 100 V............................................................................. Cap. Poly 100 nF 250 V........................................................
32 8.10 M ECHANICAL PARTS LIST The mechanical components listed below are referenced in accordance with the appropriate exploded diagrams following. 8.10.1 MR480 MECHANICAL PARTS Reference Description Part Number 1 Heaterplate Assembly 150 W 100 V................................................................................. Heaterplate Assembly 150 W 115 V................................................................................. Heaterplate Assembly 150 W 230 V..............................
33 8.10.2 EXPLODED DIAGRAMS: MR480 Ref.
34 8.10.3 MR730/720/700 MECHANICAL PARTS Reference Description Part Number 1 Heaterplate Assembly 150 W 100 V................................................................................... Heaterplate Assembly 150 W 115 V................................................................................... Heaterplate Assembly 150 W 127 V................................................................................... Heaterplate Assembly 150 W 230 V..................................................
35 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 38 Case Body Kit MR730JEU English/French Canadian Case Body Kit MR730JHB English/Spanish Baxter........................................................ NOTE: For other Case Body types Specify Model Number eg "Case Front Kit MR720ASU" Washer M6 Wavey .............................................................................................................. Nut M6 Nyloc ZPS ....................................................................
36 8.10.4 EXPLODED DIAGRAMS: MR730/720/700 Ref.
37 8.10.5 HEATERPLATE ASSEMBLY PARTS (MR730/720/700/480) Reference Description Part Number 1 2 3 4 Reflector (added after 01/01/99)....................................................................................... Screw M4 × 8 Pan Phil Taptite ......................................................................................... Cover Element Plate........................................................................................................... Element Assembly 230 V 150 W ............
38 8.10.6 EXPLODED DIAGRAMS:HEATERPLATE ASSEMBLY MR730/720/700/480 (I NVERTED VIEW) Ref.
39 8.11 PCB IDENTIFICATION DIAGRAM Ref.
40 8.12 POWER PCB HARNESS CONNECTION DIAGRAM Ref.
41 9.0 PRODUCT CHANGE HISTORY ___________________________________ This change history details changes which may have significance for servicing. It does not include changes that are insignificant to users or service technicians. Refer also to change panel on circuit diagrams.
42 9.1 M ODEL NUMBER EXPLANATION eg MR730AEU (model type MR730, with specific variations as below). The table below lists variations in models that are for general sale, there are some models which are sold to specific customers that are not shown here. 9.
43 APPENDIX A ___________________________________________________ A1 CALIBRATION M ODE Entry to the calibration mode is made by holding down the ‘Chamber Temp’ button and turning on the Mains Power switch. After a two second delay the display should show ‘-1-’. On releasing the ‘Chamber Temp’ button the display will show the humidifier model number (730/720/700 or 480). The ‘Chamber Temp’ button is now used to step between functions as shown below. 1 2 3 4 5 Model number display.
44 A2.2 ENGINEERING FUNCTIONS : NON HEATER W IRE MODE SET dc hP L CP i A2.3 Set temperature display (°C) Heaterplate duty cycle (%) Heaterplate temperature (°C) Programming link status Compare probes (Probe test) Heaterplate Integral INTEGRAL DISPLAY The integral is an error offset signal which constantly accrues to compensate for the temperature difference between the set control and probe. It is displayed in the ‘Ei’ and ‘Ti’ engineering functions in hexadecimal notation, ie.
45 Errors EP2 to EP4 can be caused for example by abnormal high differential temperatures on the two thermistors or by rapidly changing input temperatures. EP1 Hardware fault; Q13 short not effective. EP2 Low probe temperature (~0 °C). EP3 High probe temperature (~70 °C). EP4 Partial short between the active probe cable conductors. A5 MR700 SERIES HUMIDIFIER SERIAL DATA INTERFACE A5.1 SERIAL DATA FORMAT 1 byte : (semi colon) Marks beginning of data record.
46 The data record as received should start with an ‘:’ and end with an ‘LF’. Under abnormal operating conditions however (when there are ‘E’ messages in the display) some or all of the above packets ‘a’ to ‘g’ can be missing. The status information packet ‘h’ will always be present (as long as the micro is running) and will show the error condition. When there are error messages in the display, bit 6 of the last status byte will be set high indicating a fatal error condition.
47 A5.4 SERIAL DATA INTERFACE CONNECTOR A DB9 connector on the side of the humidifier provides the interface connections. pin 2 Remote shut down input (Serial in). pin 3 Serial Data output. pin 5 Humidifier Earth. pin 7 +5 V (30 mA max) Ref.
48 APPENDIX B __________________________________________________ B1 M AINTENANCE SCHEDULE The MR700 series humidifiers operating software continually monitors the performance characteristics of the humidifier reporting any errors and in the event of a fatal error terminates operation in a fail safe mode. For this reason preventative maintenance of the humidifier need only be performed at extended intervals. The following list of routine checks are recommended to be performed at the intervals stated.
49 B2 M AINTENANCE SCHEDULE CHECKLIST (PHOTOCOPY AND FILE IN MAINTENANCE RECORDS) Type of service check: q monthly q 3 monthly Humidifier Serial Number:___________________________ Monthly Three Monthly Annually q 6 monthly q yearly Date: ______________ Step Method Pass Fail Check Temperature Probe Refer Appendix B1.1 Check Reusable Heater Wire Refer Appendix B1.1 Check Heater Wire Connections Refer Appendix B1.1 Check Power Cable Refer Appendix B1.
50 APPENDIX C __________________________________________________ C1 T ROUBLESHOOTING GUIDE FOR T HE MR700 SERIES RESPIRATORY HUMIDIFIERS This is a guide to possible corrective action in the case of an humidifier alarm condition or malfunction. It is primarily written for humidifiers using heated wire mode. So parts of this guide would not be applicable for the MR480 and MR730 and MR720 in the heater wire off mode.
51 C.1.2 HIGH TEMPERATURE Condition detected Possible cause F Action to take Airway temperature high alarm activated. Sudden spurious increase in gas flow. Wait for temperature to fall below threshold. Heater wire too close to temperature probe. Use shorter heater wire or lengthen inspiratory hose so that distance is between 25 (1”) and 100 mm (4”), ideally 30 mm. Possibly faulty EOH sensor on temperature probe (low resistance). Check probe, see § 6.4. No water in chamber.
52 C1.5 C1.6 Excessive water in expiratory circuit due to rainout. Condensation due to cooling in Expiratory line. Use dual heated circuit. Water ejected from humidification chamber into circuit. Humidification chamber filled beyond maximum water level line. Rduce water level Maximum permissible peak flow rate of humidification chamber has been exceeded. Ue correct chamber. Refer to the operating instructions for the type of chamber used. Humidifier chamber tilted. Chamber should be level.
53 C1.7 TEMPERATURE DISPLAY Condition detected Possible cause FAction to take No temperature display, no alarm lights. Humidifier voltage rating incorrect. Select correct voltage rated unit. Heaterplate overheat protector operated. Reset overheat protector. Transformer over heat protector operated. Replace transformer. No temperature display, ‘see manual’ indicator light on. Control PCB fault. Check control PCB for water damage.or contamination. Error code. Humdifier failed self test.
54 C2 MR700 SERIES FAULT FLOW CHART FOR NO GO CONDITION Check Voltage Rating Of Unit YES Open Unit and check if thermal cut out under heaterplate has tripped YES Reset thermal cut out and find reason for fault NO NO Check for mains voltage at Connector J5 on power board Check mains lead and plug YES Check connectors on power board are in correct locations and secure, check fuses (F1 - F4), check voltage on connector J7of power PCB, mains switch on, connectors on rear of control board and continu
55 APPENDIX D _________________________________________________ D1 CLEANING OF HUMIDIFIER HEATER BASES These are the recommended cleaners for use with Fisher and Paykel heaterbases as of the time of revision of this technical manual. The disinfectants in the list below have been tested to ensure no damage to the outer plastic or metal components of the humidifier. If you wish to use a chemical other than these, please contact your local Fisher and Paykel Healthcare supplier. Cleaning instructions 1.
56 APPENDIX E _________________________________________________ E1 ADDITIONAL DYNAMIC PERFORMANCE CHECK OF HUMIDIFIERS This procedure is optional and may be used to check the dynamic operation of MR730/720/700 and MR480 humidifiers. This performance check can be performed if there is any doubt about the operation of the humidifier, such as after any servicing involving the printed circuit boards. For normal routine maintenance checks only the tests detailed in Section 6 are required.
57 E.2.3 3 Connect the Heater Wire cable to the humidifier. 4 If a gas supply is used, set to 5- 10 l/minute, if no gas supply used, the breathing tube should be supported from the patient end so that it drops vertically over its entire length to the top of the chamber. DYNAMIC TEST SEQUENCE (MR730/720/700) 1 Turn the humidifier on, ensure the heater wire LED is on for a MR720 or MR730. 2 Adjust set temperature to 36.0 ± 0.1 °C and Chamber Control to 0.
58 E.3.2 E.3.3 SETUP 1 Fill the humidification chamber with water and slide on to the heaterbase. 2 If a gas supply is used, set to 2- 10 l/minute, if no gas supply used, the breathing tube should be supported from the patient end so that it drops vertically over its entire length to the top of the chamber.
