MR880 Technical Manual Rev A Sept 2004 .pdf
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H
MR880 HUMIDIFIER
Technical Manual
REVISION A
September 2004
Copyright ©2004 Fisher & Paykel Healthcare Ltd.
Auckland, New Zealand
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Fisher & Paykel Healthcare
France/Benelux:
Head Office:
Parc Silic-Bal F,
PO Box 14-348, Panmure,
10 Avenue de Quebec,
Auckland 1134
Silic 512 Villebon, 91946,
New Zealand
Courtaboeuf, Cedex, France.
Email: info@fphcare.com
Tel: +33–(0)1-6446-5201
Web Site: www.fphcare.com
Fax: +33–(0)1-6446-5221
Tel: +64-(0)9-574-0100
Fax: +64-(0)9-574-0158
Australia:
USA:
36-40 New Street,
Suite 101 22982 Alcalde Drive,
Ringwood, Victoria 3134,
Laguna Hills, California 92653, USA
Australia,
Tel: +1-(949)-470-3900
Tel: +61-(0)3-9879-5022
Fax: +1-(949)-470-3933
Fax: +61-(0)3-9879-5232
Toll Free: (800)-446-3908
Germany:
UK and Ireland
Hundsbergerstrasse 45
(European Authorised Representative):
73642 Welzheim
Unit 16, Cordwallis Park
Germany
Clivemont Road, Maidenhead, SL6 7BU,
Tel: +49-(0)7182-93777-0
United Kingdom
Fax: +49-(0)7182-93777-99
Tel: +44-(0)1628626 136
Fax: +44-(0)1628626 146
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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Revision
Description of Technical Manual Change
Date Issued
A
First release of Technical manual
23/09/2004
Note:
1. Fisher & Paykel Healthcare have a policy of continued product improvement and reserve the
right to change specifications without notice.
2. This technical manual covers software version 2.22, 2.23, 3.01 and PCB revision D and E.
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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TABLE OF CONTENTS
1
INTRODUCTION ............................................................................................................................................. 5
1.1
1.2
1.3
1.4
2
HUMIDIFIER SYMBOLS................................................................................................................................ 7
2.1
2.2
3
OPERATIONAL PROBLEMS.............................................................................................................................. 15
TECHNICAL PROBLEMS .................................................................................................................................. 16
“SEE MANUAL” ERROR CODES ...................................................................................................................... 17
SERVICING PROCEDURES ........................................................................................................................ 18
7.1
7.2
7.3
7.4
8
MAINTENANCE SCHEDULE............................................................................................................................. 13
SAFETY CHECK .............................................................................................................................................. 13
CLEANING INSTRUCTIONS.............................................................................................................................. 14
TROUBLESHOOTING .................................................................................................................................. 15
6.1
6.2
6.3
7
HUMIDIFIER OPERATION .................................................................................................................................. 9
HUMIDIFIER CONTROLS ................................................................................................................................. 10
TEMPERATURE DISPLAY ................................................................................................................................ 10
SETUP INDICATORS ........................................................................................................................................ 11
OPERATIONAL ALARMS ................................................................................................................................. 12
MAINTENANCE PROCEDURES ................................................................................................................ 13
5.1
5.2
5.3
6
MECHANICAL................................................................................................................................................... 8
ELECTRICAL .................................................................................................................................................... 8
TEMPERATURE RANGE..................................................................................................................................... 8
ALARM PARAMETERS: ..................................................................................................................................... 8
PERFORMANCE ................................................................................................................................................ 8
TRANSPORT AND STORAGE ENVIRONMENTAL CONDITIONS ............................................................................ 8
STANDARDS AND APPROVALS ......................................................................................................................... 8
OPERATING MODES AND CONTROLS..................................................................................................... 9
4.1
4.2
4.3
4.4
4.5
5
GENERAL SYMBOLS ......................................................................................................................................... 7
HUMIDIFIER SPECIFIC SYMBOLS ...................................................................................................................... 7
SPECIFICATIONS ........................................................................................................................................... 8
3.1
3.2
3.3
3.4
3.5
3.6
3.7
4
ABOUT THIS MANUAL...................................................................................................................................... 5
GLOSSARY ....................................................................................................................................................... 5
DEFINITIONS .................................................................................................................................................... 5
PRODUCT APPLICATION ................................................................................................................................... 6
GENERAL CONSIDERATIONS .......................................................................................................................... 18
DISASSEMBLY ................................................................................................................................................ 18
SERVICING ..................................................................................................................................................... 19
INSTALLING THE EQUIPOTENTIAL STUD ......................................................................................................... 24
PERFORMANCE TESTING ......................................................................................................................... 25
8.1
8.2
HUMIDIFIER PERFORMANCE TESTING ............................................................................................................ 25
PROBE ACCURACY CHECK............................................................................................................................. 28
9
APPENDIX A - RECOMMENDED MAINTENANCE CHECKLIST....................................................... 30
10
APPENDIX B - CALIBRATION PROBE..................................................................................................... 31
11
APPENDIX C - SPARE PARTS .................................................................................................................... 32
11.1
12
APPENDIX D - SERIAL PORT & LOGGING SOFTWARE .................................................................... 36
12.1
12.2
13
HEATER PLATE ASSEMBLY ....................................................................................................................... 34
INTRODUCTION.................................................................................................................................... 36
OPERATING INSTRUCTIONS.............................................................................................................. 36
APPENDIX E - PRODUCT CHANGE HISTORY ...................................................................................... 38
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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1 Introduction
1.1 About this Manual
This manual is intended for qualified service personnel who will perform maintenance
and servicing on the Fisher & Paykel Healthcare MR880 Humidifier. This manual covers
the product specifications, includes a maintenance schedule, and provides the
necessary information required for servicing.
Maintenance procedures should be carried out at regular intervals (as recommended in
the maintenance schedule), to ensure that the humidifier and its accessories are working
correctly.
If a fault should occur with the humidifier, follow the troubleshooting guide (section 6) in
order to find the most likely cause. If the unit requires servicing, make sure the servicing
procedures are followed in order to prevent damage to the humidifier. After service, or as
part of the maintenance schedule, a humidifier performance check should be completed.
Due to the nature of the electronics contained within this humidifier, it is not
recommended that the printed circuit boards are serviced at a component level. Instead,
if the PCBs are found to be malfunctioning, they should be replaced.
1.2 Glossary
4-in-1 Probe
External probe consisting of four components: ambient
temperature sensor, chamber temperature sensor, flow
sensor, and heater wire adaptor.
Chamber
Device that in which the gas is heated and humidified, by
passing it over heated water.
Chamber Probe
Part of the 4-in-1 probe, this sensor assembly is used for
measuring the Probe
temperature and flow of the gas
travelling through the heated tube.
Chamber Set Point
The temperature that the humidifier attempts to maintain at the
chamber probe port.
Heated Tube
Tubing used to transport the gas to the patient.
Heater Wire
Coiled wire inside the heated tube used to heat the gas.
Heater Wire Adaptor
Part of the 4-in-1 probe, this electrical adaptor provides power
from the humidifier to the heated tube.
PCB
Printed Circuit Board.
Thermistor
A temperature sensitive resistor placed inside the chamber
probe.
1.3 Definitions
NOTE: A NOTE provides important information or explanation of procedures or
conditions which may otherwise be misinterpreted or overlooked.
CAUTION: A CAUTION statement designates the possibility of damage to this or other
equipment if a procedure is not followed exactly.
WARNING: A WARNING statement refers to conditions with a possibility of personal
injury if a procedure is not followed exactly.
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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1.4 Product Application
The MR880 is a heated humidifier designed for use in respiratory humidification. It is
used to provide optimum humidity to gases delivered to patients.
Refer to the Product Guide or your local Fisher & Paykel Healthcare representative for a
list of approved accessories.
WARNING:
The use of heated tubes, chambers or other accessories which are not approved
by Fisher & Paykel Healthcare may impair performance or compromise safety.
Ensure maintenance of grounding integrity by connection to a "hospital grade"
receptacle.
Always disconnect supply before servicing.
Ensure that the chamber probe is correctly and securely fitted. Failure to do so
may result in temperatures in excess of 43°C being delivered to the patient.
Do not touch the glass tip of the chamber temperature probe during use. Keep
black connectors dry at all times.
Visually inspect accessories for damage before use.
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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2 Humidifier Symbols
2.1 General Symbols
Type BF
Attention - consult accompanying documents
Caution: Electrostatically Sensitive Device
Alternating Current
Caution - Hot surfaces may exceed 85°C
Equipotential Stud
Drip proof protection to IPX1
C-tick for EMC
2.2 Humidifier Specific Symbols
Mute
Pressing this button turns the humidifier on or off (stand-by)
Humidity Alarm
Serial Port
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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3 Specifications
3.1 Mechanical
Dimensions:
Weight:
140 mm x 173 x 135 (without chamber fitted)
2.54 kg (without chamber fitted)
Approx. 2.62 kg (with chamber fitted, and filled with water)
3.2 Electrical
MR880 Model Number
Supply Voltage
Supply Current
MR880Axx
230 V~
1.0 A Max
Supply Frequency:
Heater Plate Capacity:
Heater Wire:
Heater Plate Thermal Cutout:
50 Hz
150 W at nominal mains voltage
22 ± 5 V ~, 2.7A Max, 60 W Max, 50 Hz
118 ± 6ºC
3.3 Temperature Range
During normal operation:
Display:
Chamber set point: 37 ºC,
(Can be 30 °C in low flow/ambient conditions)
Three digit, 14 mm, 7 segment LED
Range: 10 to 70 ºC
Accuracy: ± 0.3 ºC (in 25 to 45 ºC temperature range)
3.4 Alarm Parameters:
High Temperature Alarm:
Low Temperature Alarm:
Sound Pressure Level:
Causes an immediate visual alarm at a chamber
temperature of 41 °C (see sect. 4.3).
After 10 minutes @ 29.5 ºC causes an audible alarm.
After 60 minutes @ 35 ºC causes an audible alarm (see
sect 4.5)
NOTE: The humidity indicator will be lit when the chamber
temperature is below 35 °C, to indicate that the interface
may not be comfortable to wear.
Alarms exceed 50 dBA @1 m.
3.5 Performance
Recommended ambient temperature range:
18 to 30 ºC
Flow Range:
5 – 50 LPM
Humidity Performance:
>33 mg/L
Warm-up time:
Less than 15 minutes.
CAUTION: If operating outside the recommended temperature range, consult your
local Fisher & Paykel Healthcare representative.
3.6 Transport and Storage Environmental Conditions
Transport and Storage Conditions:
-10 to +50 °C
3.7 Standards and Approvals
IEC60601-1, IEC60601-1-2, ISO8185
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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4 Operating Modes and Controls
4.1 Humidifier Operation
The MR880 humidification system is designed to add heat and moisture to respiratory
gases. The system is used to deliver humidified air/oxygen mixes to patients requiring
respiratory humidification. The gas is passed through a humidification chamber where it
is warmed and humidified. The humidity in the gas is then maintained as it travels along
the heated tube to the patient.
The MR880 has two heating systems. The first is a heater plate, which heats the water
contained in the humidification chamber. Gas passing through the chamber is warmed
and humidified. The humidifier monitors the temperature of the gas at the chamber
outlet using the chamber probe, and controls the amount of power delivered to the
heater plate in order to maintain the chamber set point.
The second heating system is the heater wire encapsulated within the heated tube.
Humidified gas from the chamber travels through the heated tube and then the unheated
section to the patient interface, where its temperature must be maintained in order to
prevent the generated humidity from condensing. The humidifier monitors the gas flow
rate using the chamber probe and the ambient room temperature using the ambient
sensor so the gases at the patient interface contain the same heat and humidity as at the
chamber. See Figure 4.1 below for the set-up of the humidifier.
Figure 4.1 MR880 Humidifier Set up
4.1.1 Power Up Sequence
The purpose of the power up sequence is to perform internal checks on various parts of
the humidifier and provide the user with a visual and audible check.
Internal self test sequence:
1.
Test integrity of 4-in-1 probe.
2.
Test correct operation of heater wire triac.
3.
Test correct operation of protection relays.
Visual/Audio test sequence:
1.
All 7-segment display and indicator LEDs turned on.
2.
The 7-segment display is blanked and indicators set to their default.
3.
Display shows humidifier model number eg. 880.
4.
Display shows software version number with no decimal point e.g. 223.
5.
Display is blanked.
6.
Normal display (chamber temperature).
After power-on the humidifier starts an internal diagnostic routine which checks for
possible problems in the humidifier setup. If everything is working correctly, normal
control is initiated.
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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4.1.2 Fault Handling
If the humidifier detects a problem with its setup or operation it will alarm. Depending on
the severity of the alarm condition, the humidifier will either reduce or remove power
from the heating systems described above in section 4.1. For further detail on operation
under different alarm conditions see section 4.5.
The humidifier will also enter stand-by if the gas flow through the circuit is measured
below 3 LPM. In stand-by the following occurs:
• Heater wire power is set at 30%.
• Heater plate temperature is limited to 50°C.
• Heater plate power is limited to 20%.
4.2 Humidifier Controls
4.2.1 Power Button
The humidifier will power on if this button is held down briefly, but must be held for one
second to turn the humidifier off. Note that although the display is not illuminated, the
unit may still be energized. Be sure to disconnect power to the MR880 before
servicing.
4.2.2 Mute Button
The mute button silences the humidifier's audible alarm. The muted time depends on the
alarm condition. In general, alarms will be muted for 2 minutes. The chamber probe
alarm is muted for a longer time, until the humidifier determines whether the probe is in
or out. The low humidity alarm is treated differently - see section 4.5.
4.3 Temperature Display
The front panel shows the chamber temperature during normal operation. This
temperature gives an indication of the dew point (in °C) of the gas that is being supplied
to the patient. The dew point of a gas is the best indication of both its humidity and
energy content. If the temperature is above 70°C, "Hi" will be displayed. If the
temperature is below 10°C, "Lo" will be displayed.
4.3.1 Ambient Temperature and Flow Rate Display
Both the ambient temperature and flow rate can be displayed by pressing the mute
button for 3 seconds during normal operation. The readings are displayed in the
following sequence, with an audible beep between each change of display:
•
Display the ambient sensor reading in °C, and also light the ambient sensor LED to
indicate which reading is being displayed.
•
Display the flow reading in LPM, and also light the chamber probe LED, to indicate
which sensor reading is being displayed.
•
Return to normal operation display.
Each display is held for 2 seconds, or until 2 seconds after the mute button is released,
whichever is longer.
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4.4 Setup Indicators
The MR880 setup indicators, placed on the lower left of the front panel, are intended to
aid the user in identifying problems with the incorrect setup of the device and its
accessories.
4.4.1 Heater Wire Connector and Chamber Probe:
Lights if the heater wire in the heated tube has not been connected correctly, or if
the heater wire or 4-in-1’s heater wire adaptor is faulty. The humidifier will shut
down the heater wire and heater plate if this alarm is active.
This indicator is also used if the chamber probe not inserted into the heated tube
correctly. In this case the temperature display will also flash ‘---‘ to indicate that
there is no accurate chamber temperature available. On start-up, and during
rapid changes in temperature, the humidifier tests if a probe is in place by cooling
and then heating the chamber. If the humidifier finds that the probe is not inserted
into the heated tube, an alarm will be generated and the humidifier will enter
stand-by. During this alarm the humidifier will initiate a retest if a rise in
temperature is detected or after 15 minutes has elapsed.
4.4.2 4-in-1 Probe Connector:
This indicator will light if the chamber probe is not correctly plugged in, or the
probe used is faulty. The humidifier tests for the following probe fault conditions:
• 4-in-1 probe disconnected
• Chamber thermistor open or short circuited
• Flow thermistor open or short circuit (shorted probe test)
• Ambient thermistor open or short circuited
• One thermistor shorted to another (shorted probe test)
• Flow calibration resistor open or short circuit (shorted probe test)
An alarm will be generated if any of the above faults are found, and the humidifier
will shut down the heater wire and heater plate if this alarm is active.
NOTE: the shorted probe tests are only performed on start-up, or when
temperature probe or heater wire alarms are cancelled.
4.4.3 Water Out Indicator:
This indicates that there is insufficient water in the humidification.
The humidifier measures the amount of power used to obtain the chamber
temperature. If a lower than expected amount of power is used, a 'water out'
alarm is generated. It may take 20 minutes to generate an alarm especially if
there is a disturbance (change in flow).
This alarm can be cancelled by pressing the mute button. If however the water
out condition remains, the humidifier will re-alarm as described above.
4.4.4 Ambient Temperature Indicator
This indicates that the ambient temperature is being displayed on the front panel.
It is only used when the ambient temperature and flow rate display sequence is
initiated by the user (refer section 4.3.1).
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4.5 Operational Alarms
These alarms are generated if problems occur with the operation of the humidifier.
4.5.1 Humidity Indicator:
The humidity indicator is used to indicate high and low humidity present at exit of
chamber.
High Humidity Alarm:
The temperature display and patient light will flash if at any time the chamber
temperature exceeds 41°C. If this alarm occurs, the humidifier will immediately
shut down the heater wire and heater plate, ensuring energy delivered to the
patient cannot cause any energy risk.
Low Humidity Warning:
It is used to indicate that the system has not warmed up to the ideal temperature
for user comfort. The patient interface should be used once this indicator is
turned off.
Low Humidity Alarm:
The low humidity alarm indicates that a low level of humidity has been delivered
to the patient for a period of time. If the chamber temperature remains low for too
long, then a visual and audible alarm is activated. The time taken for the
humidifier to alarm is dependent on how far the chamber temperature is below
the 35°C threshold. Figure 4.2 shows the relationship between temperature, a
humidity warning and the time before a humidity alarm:
Figure 4.2 Temperature versus Time to Alarm
Pressing mute during a low humidity alarm silences the alarm for half the normal
time period, if the same temperature is maintained.
The low humidity warning and alarm can be triggered by cold or breezy ambient
conditions, or can result from using gas flow rates outside the specification of the
heated tubing, chamber or humidifier.
4.5.2 See Manual Indicator:
This indicates a serious hardware fault. Please refer to section 6
"Troubleshooting".
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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5 Maintenance Procedures
In order to keep your humidifier in good working order it is necessary to perform
maintenance at regular intervals. The maintenance schedule below is designed to
ensure testing is carried out on different heaterbase functionality in an appropriate time
frame.
5.1 Maintenance Schedule
5.1.1 MR880 Humidifier
Annually
a. Check MR880 for physical damage:
• Check the mains cable for damage, replace if necessary.
• Check the heater plate for deep scratching etc., replace if necessary.
b. Carry out a full performance test. This procedure is detailed in section 8.
NOTE: A maintenance check sheet is given in Appendix A.
5.1.2 4-in-1 Probe
Every Six months
a. Visually check the humidifier probes for physical damage:
• Check that the chamber probe's glass thermistor has not been damaged.
Replace probe if required.
• Inspect the chamber probe's glass thermistor for deposits or foreign material.
Clean probe as required.
• Check the probe cable for kinks and abrasions and damaged connectors.
• Check that the probe connectors couple with the humidifier sockets.
b. The probe accuracy and the accuracy of measuring circuits within the humidifier need
to be checked:
• Carry out a temperature accuracy test on both ambient and chamber temperature
probes.
• A flow accuracy check should be performed on the 4-in-1 probe and MR880.
These tests are outlined in section 8.2.
5.2 Safety Check
The unit should be tested to the current medical electrical standards for in-house testing
for each specific country (example, refer to AS/NZS 3551 for Australia and New
Zealand).
CAUTION: Permanent damage to this humidifier will result if the serial port is used as a
ground point during electrical safety testing. The correct ground point location is the
heater plate.
Figure 5.1 Location of ground test point on the heater plate
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5.3 Cleaning Instructions
5.3.1 MR880 Humidifiers
It is recommended that only the following cleaners be used on the MR880 as at the time
of revision of this technical manual. The disinfectants in the list below have been tested
to ensure that no damage will result to the outer plastic or metal components of the
humidifier.
Cleaning instructions
1.
2.
3.
Disconnect the humidifier from any electrical outlet.
Clean the humidifier with one of the following using a damp cloth:
Isopropyl Alcohol
Normal dishwashing detergent
DO NOT immerse the humidifier in any liquid.
Wipe the humidifier clear of any cleaning residues before use.
5.3.2 The 4-in-1’s Chamber Probe
The cleaning methods listed below meet the FDA regulations for these types of devices,
and do not affect the integrity or performance of the probe. It is the user’s responsibility
to qualify any deviations from these procedures, both for disinfecting efficacy and
physical effect on the probe. For advice on other cleaning methods not mentioned here,
contact your local Fisher and Paykel distributor.
Cleaning instructions
NOTE: Refer also to the disinfection instructions on the instruction sheet for the 4-in-1
Probe,
Ref 185042788.
1.
2.
Physically clean the probe, removing all visible contaminants.
Disinfect the probe with one of the following solutions:
Sporicidin; Sporox; Cidex; Cidex OPA
OR
Sterilise the probe using Ethylene Oxide sterilisation at 55°C (131°F), 80kPa.
(Allow at least 15 hours for residual ETO to disperse before use).
NOTE:
Follow the manufacturer’s instructions carefully.
Use the correct dilution of the disinfectant.
CAUTION: DO NOT immerse the black electrical connector plug in disinfectant.
DO NOT autoclave probes.
DO NOT use dishwater detergents or solvents.
3. Wipe the chamber probe clear of any cleaning residues before use.
4. Store in clean conditions.
Cidex
is a registered trademark of Johnson & Johnson Medical Pty. Ltd. North Ryde, NSW,
Australia.
Sporicidin
is a registered trademark of Sporicidin International Ltd, Rockville, MD 20852,
USA.
Sporox
is a registered trademark of Reckitt & Colman Inc. 1655 Valley Rd. Wayne NJ USA
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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6 Troubleshooting
6.1 Operational Problems
This section deals with faults that cause the humidifier to alarm. This may be caused by
incorrect setup, faulty accessories, or a faulty humidifier.
Symptom
Corrective Action
Reference
See manual
indicator flashing
with audible alarm
Record the displayed error code. Refer to section 6.3.
Section 6.3
See manual
indicator light
permanently on,
without an audible
alarm
1. If “PTS” is displayed on the front panel, then the production
test button is on. Ensure that the production test button is
not depressed. Replace the humidifier PCBs if the problem
persists.
Section 7.3.5
(see step 5)
2. There has been a microprocessor failure. Replace PCB’s
Section 6.2
Water Out indicator
flashes,
accompanied by an
audible alarm
1. Check that there is sufficient water in the chamber. Refill
or replace chamber as necessary.
2. Check that the gas flow rate is within specification of the
humidifier and accessories being used. Adjust as
necessary.
MR880
Instructions
3. Condensate formed on chamber probe? Dry the probe
and re-test.
4. 4-in-1 probe faulty. Complete a temperature and flow
accuracy check on the probe. Replace probe as required.
5. Humidifier faulty. Complete a performance test. Service
humidifier as required.
Section 8.2
Section 8.1
Chamber probe
alarm flashes
accompanied by an
audible alarm,
normal
temperature
display
1. Check that the heater wire is correctly plugged into the
humidifier and the heated tube.
4. Humidifier faulty. Replace PCBs.
Section 7.3.2
Chamber probe
alarm flashes
accompanied by an
audible alarm and
flashing
temperature
display
1. Check that the chamber probe is inserted into the heated
tube correctly, and that the heated tube is set up correctly.
Accessory
instructions
2. Replace heated tube, and re-test.
3. Replace 4-in-1 probe, and check for intermittent
connections. Re-test.
2. Check that there is sufficient water in the chamber. Refill
as necessary.
3. Ensure correct chamber is being used.
4. Check that the gas flow rate is within specification of the
humidifier and accessories being used. Adjust as
necessary.
MR880
Instructions
5. Has condensate formed on the chamber probe? Dry
probe and re-insert.
6. 4-in-1 probe or humidifier faulty. Complete performance
tests. Replace probe or service humidifier as required.
4-in-1 probe
connector indicator
flashes,
accompanied by an
audible alarm
Section 8
1. Is the probe connector correctly plugged into the
humidifier? Plug in probe as required.
2. Perform a humidifier calibration check.
Section 8.1.1
3. Replace 4-in-1 probe and re-test. If the alarm condition
disappears, the 4-in-1 probe is faulty. Discard faulty
probe.
Section 7.3.2
4. Humidifier faulty. Replace PCBs.
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Humidity indicator
is constantly lit
The humidifier is still warming up to optimal temperature. The
system will be comfortable to use when the indicator is not lit.
Symptom
Corrective Action
Humidity Indicator
flashes, with
audible alarm,
coupled with a low
temperature
(<35°C) displayed
The humidifier has been unable to maintain temperature over a
period of time.
1. Check that the gas flow rate is within specification of the
humidifier, and accessories being used.
Reference
MR880
Instructions
2. Check for drafts around the heated tube. This can be
caused by fans or room air conditioning. If this is found to
be the cause, the heated tube should be removed from the
path of draft. Do not cover heated tube by any means.
3. Humidifier or probe faulty. Complete humidifier & probe
performance test. Replace probe or service humidifier as
required.
Section 8
WARNING: Never cover the heated tube or place
in the path of radiant heat.
Humidity indicator
flashes and a high
temperature is
displayed
1. Has the gas flow rate been changed? Monitor the
displayed temperature for several minutes for a drop in
temperature.
2. If the temperature does not begin to fall then remove
humidifier from patient, and complete a performance test
on the humidifier, and 4-in-1 probe. Replace probe or
service humidifier as required.
Section 8
6.2 Technical Problems
Problems that cause the humidifier to malfunction without an audible alarm are
discussed in this section.
Symptom
Corrective Action
See manual
indicator lit (not
flashing)
1. Check that the mains supply is within specification.
Provide adequate mains supply if required.
Humidifier will not
turn on with on/off
button, and no
indicators are lit
Reference
2. If ‘PtS’ is displayed, refer to section 6.1.
Section 6.1
3. Replace PCBs.
Section 7.3.2
1. Humidifier plugged into mains supply?
2. Check that the mains supply is within specification.
Provide adequate mains supply if required.
3. Remove mains power and check the fuses.
Section 7.3.1
4. Check continuity of mains power cord. Replace as
necessary.
Section 7.3.6
5. Check the transformer windings are not open circuit.
Primary Winding: Red wires
Secondary 10v winding: White wires
Section 7.3.3
Secondary 22v winding: Yellow wires
If any windings are open circuit, replace the transformer.
6. Replace PCBs.
Section 7.3.2
Unit fails
calibration check
Send unit to a Fisher & Paykel Healthcare service
representative for calibration, or replace PCBs.
Section 7.3.2
4-in-1 Probe fails
probe accuracy
check
Replace probe.
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Page 17
Unit fails to reach
temperature in
heater control
check. (Section
8.1.4)
1. If the chamber outlet temperature was low, the heater plate
element should be checked. Replace element as
necessary.
Section 7.3.4
2. Replace PCBs.
Section 7.3.2
6.3 “See Manual” Error Codes
The following is an explanation of the error codes that are displayed in conjunction with
the See Manual indicator flashing. A code is not displayed if the microprocessor has
stopped functioning (see technical problems - section 6.2).
Error Description of Fault
E00
E02
E03
E04
E05
E06
E07
E10
E11
E12
E13
E14
E15
E16
E20
E21
E22
E23
E25
E26
E27
E28
E29
E2A
E2C
E2D
E30
E31
E40
E41
E42
E43
E44
E45
E4A
E4B
E4C
E50
E51
No fault
Microprocessor stack overflow
RAM fault
ROM fault
EEPROM version older than ROM version. Update EEPROM. Refer to Section 7.3.5
EEPROM version newer than ROM version – (old software). Contact Fisher & Paykel
Healthcare
Incorrect ROM type used (wrong model)
Temperature circuit calibration out of range: Range Amp 0: 25.5°C
Temperature circuit calibration out of range: Range Amp 0: 65.0°C
Temperature circuit calibration out of range: Range Amp 1: 25.5°C
Temperature circuit calibration out of range: Range Amp 1: 34.5°C
Temperature circuit calibration out of range: Range Amp 2: 34.5°C
Temperature circuit calibration out of range: Range Amp 2: 44.6°C
Temperature circuit calibration out of range: Range Amp 3: 60.0°C
Heater wire circuit is not functioning:
- Heater plate thermal cutout tripped (section 7.3.4)
- Heater wire fuse (F2) is open circuit (section 7.3.1)
- Heater wire triac drive, or heater wire relay is open circuit
Heater wire triac is short circuit
Incompatible circuit type – software upgrade needed to use in mask mode
Triac circuit sense fault
Transistor Q17 is not turning on
Transistor Q16 is not turning on
The heater wire relay is short circuited
Mains voltage measurement is uncalibrated (section 8.1.3)
The heater plate thermistor is short circuit
The heater plate thermistor is open circuit
Heater plate element is not turning on:
- Element is open circuit, or
- Heater pate triac/triac driver faulty or
- Heater plate relay is faulty
The heater plate element is not turning off. Heater plate triac circuit faulty.
Power (on/off) button stuck on
Mute button stuck on
Unit not functional tested at time of manufacture
Failed the functional test at time of manufacture
Was not stress tested during manufacture
Failed the stress test during manufacture
Not tested on functional tester 2
Failed production functional tester 2
EEPROM write error occurred
EEPROM write verify error occurred
EEPROM read error occurred
Flow circuit open fault
Flow shorted fault
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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Page 18
7 Servicing Procedures
7.1 General Considerations
WARNING: Although the MR880 display may not be illuminated, the unit may still
be energized. Be sure to disconnect the MR880 from the power supply before
servicing.
All servicing procedures should be followed by a humidifier performance test, and
an electrical safety test to ensure proper operation. The performance tests are
outlined in section 8.
CAUTION: Where screws and bolts have been removed from the product, do not use
excessive force when re-fastening.
Antistatic procedures should be followed when servicing this product.
7.2 Disassembly
7.2.1 Opening the case
1.
2.
3.
Ensure mains power is disconnected from the unit.
Remove the four screws at the back of the humidifier.
Remove front half of case by sliding the two halves apart. Pull the front half of the
case away from the rear. See figure 7.1.
Figure 7.1. Showing two halves of case being slid apart.
4.
The control PCB is attached to the front half of the case. The PCB in the rear half
of the case is the power PCB.
Slide the power PCB forward with the side panel (the side panel is attached to
the power PCB). The side panel will need to be pushed inwards during the sliding
action in order to unlatch and clear the electrical connector.
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Page 19
5.
Un-clip the three fasteners (figure 7.2) which hold the front (control) PCB to the
front of the case, and separate the front PCB from the case.
Figure 7.2 Showing PCB fasteners.
7.2.2 Closing the case
1.
2.
3.
4.
5.
Make sure that all harnesses that were previously disconnected have been
reconnected. If the mains wiring was disconnected during servicing, check that
the mains polarity is correct (see table on previous page).
Slide the power PCB back into position, ensuring that the side panel slides in the
slots and latches into the case rear.
Place the control PCB back into position in the front of the case, ensuring all clips
are located properly.
Slide the case together, and replace the four screws.
In order to check that the humidifier is working properly, complete a full
performance test as outlined in section 8.
7.3 Servicing
7.3.1
Replacing Fuses
1.
2.
Open the case (see 7.2.1).
The fuses can now be accessed. See figure 7.3 for the location of the fuses on
the power PCB.
F4 F3
F1
F2
Figure 7.3 Showing location of the fuses on power PCB.
The four fuses have the following ratings and its part numbers:
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Page 20
MR880 Model Number
MR880AEA
Supply Voltage
230V ~
Fuse Type
F1: 1A 250V FastBlow
F2: 4A 125V FastBlow
F3: 2A 250V FastBlow
F4: 2A 250V FastBlow
Part Number
999 830 001
999 830 017
999 830 009
999 830 009
WARNING:
Be sure to replace the fuse with the correct rating and type. Do not under any
circumstances replace F2 with anything other than a fast blow fuse of the type and
rating specified, as serious injury could result.
3.
4.
Replace fuse.
Close the case (section 7.2.2).
7.3.2 Replacement of Printed Circuit Boards (PCBs)
1.
2.
3.
4.
5.
6.
Open the case (see section 7.2.1).
Disconnect all harnesses attached to the power PCB. Disconnect the mains and
protective earth wires by unscrewing the terminal blocks and cutting the cable
ties (see figure 7.4).
Remove PCBs, and send for servicing. Note that the side panel (including the
connector) is replaced, along with the power PCB.
Unpack replacement PCBs, replace the mains fuses (F3, F4) with the correct
type, and attach mains and protective earth wires, using the cable ties provided.
See figure 7.4.
Connect harnesses from the transformer and heater plate to the power PCB.
Close the case (section 7.2.2).
Transformer
Primary
Thermal cutout &
thermistor
Heater plate
element
Transformer
Secondary
Mains cord
phase
Mains cord
neutral
Heater plate & mains cord earth
Figure 7.4 Showing Humidifier Power PCB wiring
7.3.3 Replacement of Transformer
1.
2.
3.
4.
5.
6.
Open the case (see section 7.2.1).
Disconnect the transformer primary and secondary harnesses attached to the
power PCB.
Unscrew the four mounting screws fixing the transformer, and remove the
transformer from the case.
Place the new transformer inside the case, and mount using the four screws.
Connect transformer primary and secondary harnesses to the power PCB.
Close the case (section 7.2.2).
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Page 21
7.3.4 Servicing the Heater Plate
Resetting the thermal cutout.
1.
2.
Open the case (see section 7.2.1).
Check the thermal cutout on the heater plate by pushing the red button with a
pen or small screwdriver - see figure 7.5.
Figure 7.5 Showing location of thermal cutout.
3.
If the thermal cutout "clicks" when pushed, it has been previously activated, and
is now reset.
If the heater plate is still hot, it must be allowed to cool sufficiently
before the thermal cutout will reset.
Close the case (section 7.2.2).
NOTE:
4.
Replacing the heater plate thermistor
NOTE: A Heater plate thermistor service kit is required. (Part Number: 043 041 254)
1.
Open the case (see section 7.2.1).
2.
Disconnect the heater plate element, thermistor and thermal cutout harnesses
attached to the power PCB.
3.
Remove the three screws holding the heater plate - see figure 7.6.
Figure 7.6 Showing location of Heater Plate screws.
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Page 22
4.
5.
6.
Cut cable ties attached to the heater plate harnesses.
Remove screw holding heater plate thermistor - see figure 7.7.
Desolder the wires attached to the thermal cutout, and remove the old thermistor
and harness.
Thermal cutout
Thermistor
Figure 7.7 Location of heater plate thermistor,
thermal cutout and element screws.
7.
8.
9.
10.
11.
12.
Place the new thermistor into position, and attach using the screw.
Solder the wires from the new harness to the heater plate thermal cutout.
Attach the cable ties provided to the heater plate harness.
Place heater plate back into position, ensuring the springs underneath the heater
plate are in place. Attach to the humidifier's case using the three long screws that
were previously removed.
Connect the heater plate element, thermistor and thermal cutout harnesses to the
power PCB.
Close the case (section 7.2.2).
Checking the heater plate element
1.
2.
3.
Open the case (see section 7.2.1).
Disconnect the heater plate element, thermistor and thermal cutout harnesses
from the power PCB.
Measure the resistance between the 2 contacts on the heater plate element
connector (this is the large three pin connector).
The resistance of the heater plate element should measure the same as outlined
in the table below:
MR880 Model Number
MR880AEA
Supply Voltage
230V ~
Heater Plate Resistance
353 + 12 Ohms
If the measured resistance is outside this range, replace the heater plate element
(steps 4 to 9). If the heater plate element is within specification, go to step 10.
NOTE:
4.
If the heater plate element requires replacing, a heater plate element
service kit is required - see Appendix C: Heater Plate Assembly.
Remove the two visible screws holding the heater plate element reflector.
Remove the shield, making sure the washers are not lost. Unscrew the last four
screws on the element cover (see figure 7.7).
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Page 23
5.
6.
7.
8.
9.
10.
11.
Remove the heater element, leaving the mica insulator in place.
Insert the new element into position, making sure the insulating mica is between
the element and the heater plate.
Replace the element cover, using the four screws that were previously removed.
Replace the element reflector, making sure the washers that separate the
reflector from the cover are placed back into position. Screw into place.
Place the heater plate assembly back into position, ensuring the springs
underneath the heater plate are in place. Attach to the humidifier case using the
three long screws that were previously removed.
Connect the heater plate element, thermistor and thermal cutout harnesses to the
power PCB.
Close the case (section 7.2.2).
Replacing the Thermal Cutout
Note: A thermal cutout service kit is required. (Part Number: 349 040 052)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Open the case (see section 7.2.1).
Disconnect the heater plate element, thermistor and thermal cutout harnesses
from the power PCB.
Remove the three screws holding the heater plate - see figure 7.7.
Desolder the two black wires attached to the thermal cutout.
Unscrew fasteners used to secure the thermal cutout, and remove.
Place new thermal cutout in position and fasten using screws provided.
Depress the thermal cutout's red button to ensure it is reset.
Solder the black wires that were previously disconnected to the contacts on the
new thermal cutout.
Place heater plate back into position, ensuring the springs underneath the heater
plate are in place. Attach to the humidifier's case using the three long screws that
were previously removed.
Connect the heater plate element, thermistor and thermal cutout harnesses to the
power PCB.
Close the case (section 7.2.2).
7.3.5 Installing New Software
1.
2.
Open the case (see section 7.2.1).
Remove ROM integrated circuit U3 (see figure 7.8) using appropriate tools.
Figure 7.8 Location of U3 ROM
3.
4.
5.
Place new ROM into the empty socket, ensuring correct orientation.
Close the case (section 7.2.2)
Turn the humidifier upside down; use a non conducting tool to hold the production
test button down. This button is accessible through the right air vent slot (when
looking at the rear of the humidifier). - See figure 7.9.
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Page 24
WARNING: Never use an electrically conducting tool to depress the
production test button, as there are live mains voltages inside the
humidifier.
Figure 7.9 Showing Location of the Production Test Button.
5.
6.
7.
Apply mains power to the humidifier, while keeping the production test button
depressed. The display should read: “PTS”. This ensures that the new software
version number will be properly updated in the EEPROM.
Turn off the mains power to the humidifier, and remove the tool.
Check that the humidifier powers up normally, and complete a full performance
test (section 8).
7.3.6 Replacing the mains cable
1.
2.
Open the case (section 7.2.1).
Unscrew the three mains cable wires from the terminal blocks on the power PCB
(see figure 7.4), and cut the cable tie on the PCB.
3.
Slide the mains cable retainer away from the rear of the case.
4.
Replace the power cord, and affix to the case by forcefully pushing the retainer
back into position (towards the rear of the case).
Attach the 3 mains cable wires to the terminal blocks on the power PCB (see table below for
correct mains cable wiring), and attach the phase and neutral wires with a new cable tie.
CORD TYPE
NZ / AUSTRALIA
(230V)
PHASE
Brown
NEUTRAL
Blue
EARTH
Green / Yellow
WARNING: When attaching the mains cable wires, ensure that the correct
polarity of the mains wiring is followed. The table given above only applies
to power cords supplied by Fisher & Paykel Healthcare.
5.
Close the case (section 7.2.2).
7.4 Installing the equipotential stud
1.
2.
3.
4.
5.
6.
Open the case (section 7.2.1).
Create the stud hole by puncturing the perforation beneath the heater base shell (figure
7.10)
On the underside of the heater base, fit the green/yellow washer in place, followed by
the wavy washer, and followed by the stud.
On the inside, fit the remaining components over the equipotential stud in the following
sequence: Flat washer; ring terminal on the earth wire; star lock washer; M6 Nut.
Insert the crimped end of the earth wire into the spare hole on the earth bar of the
MR880 PCB, and tighten using brass screw supplied.
Close the case (section 7.2.2).
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Page 25
Stud
Puncture the
stud hole
Green/yellow
washer
Stud
Ring
terminal of
earth wire
M6 Nut
Star lock
washer
Wavy
washer
Flat washer
Figure 7.10 Installing the stud components
8 Performance Testing
This section discusses the performance testing of the MR880 humidifier and also the
MR880’s 4-in-1 probe. Performance testing is required as part of ongoing maintenance
or after servicing of the humidifier has been completed.
8.1 Humidifier Performance Testing
If the humidifier has been operating normally, but a performance check is required as
part of the maintenance schedule, it is recommended that the following tests are
completed:
1.
2.
A humidifier Calibration Check (section 8.1.1)
A humidifier Display Check (section 8.1.2)
However, if there is a problem with the humidifier, or if the humidifier has recently been
serviced, then the following tests should be completed in addition to those outlined
above.
3.
4.
A humidifier Voltage Calibration Check (only required if the MR880's PCBs or
mains transformer have been serviced or replaced.) (Section 8.1.3)
A humidifier Warm-up and Control Check. (Section 8.1.4)
Entering the Service Menu
The MR880 humidifier has a special mode which enables the operator to verify correct
operation. To enter this mode, hold down the power button on the front of the humidifier
then apply mains power. The See-Manual indicator will light, and the humidifier will enter
the service menu. The service menu has six different tests:
MR880 Technical Manual * Ref. 185043483 (Internal 185043679) * Revision A * Issued September 2004
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