Nidek Medical Mark 5 Nuvo Lite Family User manual

Nidek Medical Products, Inc®
Mark 5 Nuvo® Lite Family of Oxygen Concentrator
Service Manual for Serial Numbers beginning 013- XXX
Manual Number 2010-8407 Revision D
Nidek Medical Products, Inc.
3949 Valley East Industrial Drive Birmingham, Alabama 35217 SA
Telephone: [phone] • 24-Hour Fax: [phone]
Nidek Medical is a trademark of Nidek Medical Products, Inc.
Mark 5 Nuvo® Lite is a registered trademark of Nidek Medical Products, Inc

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Table of ontents 2
General Safety Instructions
Production and Use of Oxygen 5
Use and Maintenance of the Device 5
Standards and Regulations 5
Section 1.0 Introduction
1.1 Home Service Provider Responsibility 6
1.2 Important otice and Symbol Explanations 7
1.3 Functional Specifications 8
Section 2.0 Operational Check and Concentration Test
2.1
2.2
2.3
2.4
2.5
Description of Operation
Operation Check
Alarm System
2.3.1 Power Failure Alarm test
Oxygen Concentration Test and Specification
o Oxygen Flow Alarm test Procedure
9
9
10
10
10
11
Section 3.0 Patient Instructions
3.1
3.2
General Instructions
Routine Maintenance by the Patient
10
11
3.2.1 Cleaning the Cabinet Air Filter
3.2.2 Checking the Power Alarm System
11
12
Section 4.0 Home Service Provider aintenance
4.1 Routine Maintenance 12
4.1.1 Cabinet Air Filter 12
4.1.2 Final Product Filter Replacement 12
4.1.3 Compressor Inlet Air Filter Replacement 13
4.1.4 Recording Maintenance 13
4.2 Cleaning Unit 13
4.2.1 Preparing for ew Patient Use 13
Section 5.0 Service
5.1 Components 13
5.2 Cabinet Removal 14
5.2.1 Removing Cabinet Back 14
5.2.2 Caster Replacement 14
5.3 Compressor 14
5.3.1 Compressor Replacement 15
5.3.2 Capacitor Replacement 16
5.4 Process Control Valve 16
5.5 Sieve Bed Replacement 16
5.5.1 Sieve Bed Removal 17
5.5.2 Sieve Bed Installation 17
5.6 Cabinet Fan Replacement 17

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5.7 Circuit Board Replacement 18
5.7.1 Alarm Circuit Board Removal 18
5.7.2 Timing Circuit Board Removal 18
5.8 Product Regulator Check and Setting 18
5.8.1 Product Regulator Cleaning or Rebuilding 19
5.9 Pressure Monitoring Board Replacement 19
5.10 Circuit Breaker Replacement 19
5.10.1 Circuit Breaker Removal 19
5.10.2 Circuit Breaker Installation 19
5.11 I/0 (O /OFF) Power Switch Replacement 20
5.11.1 I/0 (O /OFF) Power Switch Removal 20
5.11.2 I/0 (O /OFF) Power Switch Installation 20
5.12 Buzzer Replacement 20
5.13 Hour Meter Replacement 20
5.14 Flow Valve Replacement 20
5.14.1 Flow Valve Removal 20
5.14.2 Flow Valve Installation 20
5.15 Power Cord Replacement 20
Section 6.0 Troubleshooting
6.1 Air Pressure Test (P1) 21
6.1.1 High Air Pressure (P1) 23
6.1.2 Low Air Pressure (P1) 23
6.2 Product Pressure Test (P2) 23
6.2.1 Low Product Pressure 24
6.2.2 High Product Pressure 24
6.3 General Troubleshooting 25
6.4 Troubleshooting Chart 26
6.5 Tool Kit, Oxygen Purity Testing and Pressure Test
Gauge
28
Exploded Drawings / Parts
A-1: Flow Schematic – OCSI Option 29
A-2: Flow Schematic – Standard Option 29
A-3 Flow Schematic – o Flow Alarm 30
A-4 115 / 230 Volt Electrical Schematic 31
A-5 Electrical Schematic – o Flow Alarm 33
A-6: Compressor Assembly 34
A-6-A:
Parts, Compressor Assembly 35
A-7: Front Cabinet Assembly 36
A-7-A:
Parts, Front Cabinet Assembly 37
A-8: Back Cabinet Assembly 38
A-8-A:
Parts, Back Cabinet Assembly 39
A-9: Module Assembly 40
A-9-A:
Parts, Module Assembly 41
A-10: Service and Maintenance Log 42
 General Safety Instructions

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Production and use of oxygen
Oxygen is not a flammable gas, but accelerates the combustion of materials. To prevent fire risks, the
MARK 5 NUVO Lite should be kept away from flames, incandescent sources or sources of heat
(including cigarettes) and combustible products such as oil, grease, solvents, aerosols, etc.
Do not use in an explosive atmosphere.
revent oxygen from accumulating on upholstered seats or any other fabric. If the concentrator
operates without being administered to a patient, locate it so that the flow of product gas produced is
dissipated into the air.
Locate the equipment in a free space (filter to the rear and below) which is well ventilated and free of
fumes or atmospheric pollution.
Use and Maintenance of the Device
Use the electric cable provided and check that the voltage of the mains socket used complies with the
electrical characteristics of the appliance indicated on the manufacturer's plate on the rear of the
device.
Do not use an extension cord or multiple sockets which can create sparks and therefore pose a fire
risk.
Use of the MARK 5 NUVO Lite must be restricted solely to medically prescribed oxygen therapy in
compliance with the prescribed rate and duration.
Use in other circumstances may represent a hazard to patient health.
Do not use in a specifically magnetic environment (MRI, etc.).
The MARK 5 NUVO Lite has an audible alarm intended to warn the user of any problems. The user
must determine the maximum distance away from the Nuvo Lite based on the on the sound levels in
the environment, to ensure that the alarm is always audible.
Standards & Regulations
In compliance with UL 0 01-1 [EN 0 01-1] (para .82.b):
"The manufacturer, assembler, installer or distributor are not considered to be responsible themselves
for the consequences on the safety, reliability and characteristics of a device unless the:
• Assembly, fitting, extensions, adjustments, modications or repairs have been performed by persons
authorized by the party in question.
• Electrical installation of the corresponding premises complies with local electrical codes. (e.g. IEC /
NEC).
• Device is used in accordance with the instructions for use.
If the replacement parts used for the periodic servicing by an approved technician do not comply with
the manufacturer’s specications, the manufacturer is not responsible in the event of an accident.
Do not open the equipment when it is powered on: risk of electrocution.

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This device complies with the requirements of the FDA Quality System Regulation and EU Directive
93/42/EEC, but its operation may be affected by use in the surrounding area of appliances such as
diathermy, high frequency electro-surgical instruments, defibrillators, short wave treatment appliances,
cell-phones, CB devices and other portables, microwave ovens, induction hot plates or remote control
toys, and more generally, by electromagnetic interference exceeding the levels specified in standard
IEC(EN) 60601-1-2:2001.
As a regulated medical device, both manufacturers and service providers have certain responsibilities
regarding complaints.
FDA defines a complaint as any written, electronic or oral communication that alleges
deficiencies related to the identity, quality, durability, reliability, safety, effectiveness or
performance of a device that has been released for distribution.
Service providers have a responsibility to evaluate any complaints received from their direct
customers. ( Ref. CFR 820.198 ). Nidek Medical does not have direct links to your customers.
Your evaluation should include the following:
• Determine if the complaint warrants action by Nidek Medical,
• If NO, resolve the complaint with your customer,
• If YES, contact Nidek Medical customer service,
• Work with Nidek Medical to resolve all complaints.
1.0 Introduction
1.1 Home Service Provider Responsibility
All Home Service roviders of the Nidek Medical MARK 5 NUVO Lite Oxygen Concentrator must
assume responsibilities for handling, operational testing, patient instruction, and maintenance. These
responsibilities are outlined below and throughout this manual.
 WARNING
MARK 5 NUVO Lite units must not be used for or with any life-supporting or life sustaining
applications. atients unable to communicate discomfort while using this device may require additional
monitoring. Advise patients to immediately notify their Home Service rovider(s) and/or physician(s) in
case of an alarm or any discomfort.
As a Home Service rovider, you must do all of the following:
• Inspect the condition of each MARK 5 NUVO Lite unit immediately upon delivery to your
business location. Note any sign of damage, external or internal, on the delivery receipt,
and immediately report it directly to both the freight company and Nidek Medical roducts,
Inc.
• Check the operation of each MARK 5 NUVO Lite before delivery to a patient. Always
operate the unit for a reasonable length of time and check that the oxygen concentration

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level is within specifications as referred to in Section 2.4. Test the power failure alarm as
described in Section 2.3 of this manual.
• Deliver MARK 5 NUVO Lite units only to patients authorized by a physician’s prescription.
The MARK 5 NUVO Lite must not be used as a life-supporting or life sustaining device. A
backup supply of oxygen must be available.
• Instruct patients and patient caregivers how to use the MARK 5 NUVO Lite in conjunction
with the Users Manual.
• Instruct patients and patient caregivers to notify their physicians and/or Home Service
roviders if they experience any signs of discomfort.
• Instruct each patient and patient caregivers how to perform routine maintenance of the
cabinet air filter and how to check the alarm system. (Refer to Section 3.2.)
Be available to service each patient at any time. Maintain the MARK 5 NUVO Lite in
accordance with Section 4.0.
Repair components and replace parts only as outlined in this manual. Use only Nidek Medical parts for
replacement in MARK 5 NUVO Lite Oxygen Concentrators.
• Refer to the MARK 5 NUVO Lite roduct Warranty if parts replacement is required within
the warranty period.
1.2 Important Notice and Symbol Explanations
As you read the manual, pay special attention to the WARNING, CAUTION, and NOTE messages.
They identify safety guidelines or other important information as follows:
WARNING: Describes a hazard or unsafe practice that can result in severe bodily
injury or death.
CAUTION: Describes a hazard or unsafe practice that can result in minor bodily
injury or property damage.NOTE: rovides information important
enough to emphasize or repeat.
NOTE rovides information important enough to emphasize or repeat.
The following harmonized symbols (pictograms) are located in the User’s Guide of the MARK 5 NUVO
Lite unit:

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Read the accompanying documents; particularly the User's Guide
Store, ship and use the device in an upright condition
No smoking within 2 meters (six feet) of this device, oxygen-carrying
tubing, or accessories.
Indicates an alarm signal for low oxygen concentration or other problem
Do not use any oil or grease on or near the device
1.3 Functional Specifications
Dimensions: 35.6 cm long, 22.9 cm wide, 58.5 cm high
(14 in. long, 9 in. wide, 23 in. tall)
Weight: 14.5 kg [32 Ib] varies with sound attenuation package
Electrical 115 VAC, 60 Hz, +/- 10% <330 watts(avg)
Requirements: 230 VAC, 50 Hz, +/- 10% <300 watts(avg) (185 W for 935)
230 VAC, 60 Hz, +/- 10% <330 watts(avg) (280 W for 925/60K))
Capacity: Max. 5 liters per minute
Max. 3 liters per minute (for 935 and 925/60K)
Accuracy: Flow Valve ±10% indicated flow rate or +/- 200 ml whichever is greater as
per ISO 8359 Standard
Concentration: 2 liters per minute at >90%
3 liters per minute at 90% (+ 6.5 / - 3%) for 3l/min units
5 liters per minute at 90% (+ 6.5 / - 3%)
(Based on 21°C [70°F] at sea level)
Response Time: Acceptable concentration is normally achieved in about 90 seconds; allow
5 minutes to attain full concentration.
ositioning: Operate the unit in an upright position, maintaining at
least 15 cm (six inches) of open space on all sides for ventilation.
.
2.0 Operational Check and Concentration Test
2.1 Description of Operation

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Air enters the MARK 5 NUVO Lite Oxygen Concentrator through an external cabinet air filter. This
filtered air enters the compressor via a suction tube and fine filter, which quiets the suction sounds
made by the compressor. ressurized air then exits the compressor and passes through a heat
exchanger into a pair of 3-way solenoid valves. The heat exchanger reduces the temperature of the
compressed air. Next, the solenoid valve directs the air into one of two sieve beds that contain
molecular sieve. The special characteristic property of molecular sieve is that it physically attracts
(adsorbs) nitrogen when air passes through this material, thus enabling the production of high purity
oxygen.
There are two sieve beds or adsorbent columns; while one produces high purity oxygen, the other is
purged of the nitrogen it adsorbed (collected) while it was producing oxygen. Each column produces
oxygen for approximately five seconds and delivers it to the product storage volume tank integrated
into the sieve module. Oxygen exits the product storage tank through a pressure regulator, flow control
valve, and final product filter. The flow control valve, controls the flow rate of oxygen delivered to the
patient. The MARK 5 NUVO Lite unit delivers up to 95% oxygen concentration at flow rates from
0.125 to 5 l/min. The remaining constituents of the product gas stream are nitrogen and argon, both
of which are part of the air we breathe, are inert and are completely safe.
2.2 Operational Check
Nidek Medical runs each device through a burn in period and tests every MARK 5 NUVO Lite Oxygen
Concentrator thoroughly after manufacture before releasing it for shipment. As the Home Service
rovider, it is your responsibility to perform the following test to ensure that no damage occurred in
shipping or handling.
1. Open and inspect all concentrator cartons upon receipt. Unpack each unit and remove it from
its carton. Inspect the unit itself for damage. If the exterior of the carton is damaged, or the
unit itself is damaged, note it on the freight bill signed by the driver.
2. lug in the power cord of the unit, and set the I/0 (ON/OFF) switch to the I (ON) position.
Check to see that the following occurs:
3. The compressor runs, listen for the sound.
4. Exhausted cooling air flows out of the bottom rear of the unit.
5. O TIONAL for Units Equipped with Oxygen Concentration Status Indicator (OCSI): The OCSI
green light flashes until the oxygen concentration reaches 85% ± 3% (approximately two
minutes).
6. O TIONAL for Units Equipped with No Oxygen Flow Alarm Board: The No Oxygen Flow board
test should be preformed as in Section 2.5 of this manual.
7. After performing the above steps, remove the power cord from the wall outlet. Actuate the I/0
(ON/OFF) switch to the I (ON) position and note that the audible alarm sounds intermittently.
(See Section 2.3). If the unit does not initially sound off, plug the unit in and allow the unit to
run approximately 10 minutes to charge the capacitor and repeat the test. Move the switch to
the 0 (OFF) position.
8. Turn the flow valve adjustment knob clockwise until it stops (wide open). The flow valve should
indicate 5 liters/min. (or 3 liters/min. model specific) and the output of the unit should be 5
liters/min. or (3 liters/min) If not, refer to Section 5.8 to adjust the product regulator.
9 erform an oxygen concentration test, as described in Section 2.4.
2.3 Alarm System
The MARK 5 NUVO© Lite Oxygen Concentrator is equipped with a capacitor powered alarm system,
which sounds an intermittent alarm when a power failure occurs and a continuous alarm when one or

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more cycle variables are not within specification. It sounds an alarm if the high or low pressure
indicators are activated or if the optional OCSI detects lower than predetermined levels of oxygen
concentration. The alarm remains on until you correct the alarm condition or you set the I/0 (ON/OFF)
switch to the 0 (OFF) position. Refer to Section 6.0 for a list of probable alarm causes.
2.3.1 Power Failure Alarm Test
To test the power failure alarm, perform the following actions:
1. Unplug the power cord from the wall outlet, and set the I/0 (ON/OFF) switch to the I (ON)
position.
2. If the unit has been stored for a prolonged period, Allow unit to run for approximately 10
minutes to charge the capacitor and re-test the unit.
3. This should immediately activate the intermittent audible alarm. If it does not, refer to the
troubleshooting chart in Section 6.0 of this manual.
2.4 Oxygen Concentration Test and Specification
To ensure that the output of oxygen from the device is within specification, you must perform an
oxygen concentration test. Test the unit upon delivery to a patient and at periodic intervals. Home
Service roviders, based on their expertise and documentation, may establish and implement their own
plans for checking oxygen concentration. Consult Nidek Medical’s Service and Maintenance Log (A-
11) for the recommended maximum intervals for testing.
1. If an oxygen humidifier bottle is used, remove it from the oxygen outlet.
2. Connect a calibrated oxygen concentration analyzer to the oxygen outlet.
3. Set the I/0 (ON/OFF) power switch to the I (ON) position. (It takes approximately five minutes
for the oxygen concentration to stabilize.) Take oxygen concentration readings over a period of
several minutes to reduce any cyclic variations
4. Verify that the product flow rate delivered by the unit matches the patient’s prescription and
does not exceed the capacity of the unit.
5. Disconnect the oxygen analyzer, and reconnect the humidifier bottle (if used) and any other
equipment / accessories that may be required.
6. Adjust the flow valve adjustment knob to the prescribed flow rate.
Nidek Medical MARK 5 NUVO Lite Concentration Specifications
Liter Flow Specification
2 l/min greater than 90%
5 l/min (or 3 l/min models) 90% + 6.5 / - 3%
 NOTE:
Do not measure oxygen concentration output after the product stream passes through a humidifier
bottle. Erroneous readings will result and your oxygen concentration measuring device might be
damaged.
2.5 No Oxygen Flow Alarm Test Procedure
A No Oxygen Flow Alarm board is available as an option with the Nuvo Lite

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Oxygen Concentrator. To test the function of “No Flow” alarm if so equipped, follow the instructions
below:
1. Turn Concentrator on and allow the unit to reach normal operating purity.
2. Adjust the Oxygen Flow to desired flow rate.
3. Block the oxygen flow at the patient outlet
4. A continuous audible alarm should sound as long as the Oxygen flow is blocked
3.0 Patient Instructions
3.1 General Instructions
It is important that patients thoroughly understand how to operate the Nidek Medical MARK 5 NUVO
Lite unit. This enables proper treatment as prescribed by a qualified, licensed physician. You must
explain that the purpose of this therapy is to alleviate symptoms. If patients experience any discomfort
or the unit alarm sounds, they must notify their Home Service rovider and/or physician immediately.
You, as the Home Service rovider, are responsible to see that each patient receives the User's Guide.
Explain each step in the operation of the unit to the patient in reference to that guide.
3.2 Routine Maintenance by the Patient
To ensure accurate output and efficient operation of the unit, the patient must perform two simple
routine maintenance tasks:
• Clean the cabinet air filter
• Check the alarm system
3.2.1 Cleaning the Cabinet Air Filter
● NOTE: The patient must clean this filter weekly, as described below. The filter may
require more frequent cleaning if the MARK 5 NUVO Lite unit operates in a harsh environment such
as a house heated by wood, kerosene, or oil, or one with excessive cigarette smoke.
1. Remove the dirty cabinet air filter from the back of the MARK 5 NUVO Lite unit,.
2. Wash the dirty filter in warm water with household detergent, and rinse.
3. Use a soft absorbent towel to remove excess water.
4. Reinstall the clean cabinet air filter on the grille in the back of the unit. Be careful that the filter
edges are under the tabs.
3.2.2 Checking the Power Alarm System
See rocedure described in aragraph 2.3.1
4.0 Home Service Provider Maintenance
4.1 Routine Maintenance

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The MARK 5 NUVO Lite unit has three filters that require inspection and scheduled maintenance or
rep acement.
To ensure that the output of oxygen from the unit is within specification, you must perform an oxygen
concentration test. Test the unit upon delivery to a patient and at periodic intervals. Home Service
roviders, based on their expertise and documentation, should establish and implement their own
practices for checking oxygen concentration. The interval established may be longer or shorter than 90
days, which is the default time period recommended for providers who do not choose to establish their
own method.
Nidek Medical does not require preventive maintenance on the concentrator. You do not need to
perform any maintenance as long as the MARK 5 NUVO Lite unit remains within specifications at the
prescribed flow rate. (Refer to Section 2.4)
4.1.1 Cabinet Air Filter
The external cabinet air filter is located on the back of the unit, You can easily remove it by hand.
Instruct the patient to clean this filter weekly. (Refer to Section 3.2.1.)
NOTE:
The filter may require more frequent cleaning if the MARK 5 NUVO Lite unit operates in a harsh
environment such as a house heated by wood, kerosene, or oil, or one with excessive cooking,
cigarette smoke or atmospheric dust.
4.1.2 Final Product Filter Replacement
The final product filter does not require periodic replacement; it needs to be replaced only if it restricts
oxygen flow. It is suggested that it be replaced whenever the sieve module is repaired or replaced and
after the compressor is rebuilt.
1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unp ug the power cord.
2. Remove the upper upper cabinet back to locate the final product filter.
NOTE: Observe the position of the filter ( flow direction ) before removal.
3. Separate the silicone tubing from both sides of the filter.
4. Install the new filter with the inlet side in the same position as before. ush the tubing together
so that it overlaps the barbs of the final product filter connections.
5. Record information about the final product filter replacement in Appendix 11 of this manual and
online at www.nidekmedical.com under the ‘Maintenance Log’ tab.
6. Reinstall the upper upper cabinet back.
4.1.3 Compressor Inlet Air Filter Replacement
The inlet air filter requires inspection at each patient visit. The filter should be replaced every 2 years,

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or more often depending on environment.
1. Set the unit I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power cord.
2. Remove the cabinet air filter to locate the inlet air filter.
3. Remove filter from the unit, and replace with a new filter.
4. Record information about the filter replacement in Appendix 11 of this manual and online at
www.nidekmedical.com under the ‘Maintenance Log’ tab.
5. Reinstall the cabinet air filter.
NOTE: The filter may require more frequent cleaning if the MARK 5 NUVO Lite unit operates in a
harsh environment such as a house heated by wood, kerosene, or oil, or one with excessive cooking,
cigarette smoke or atmospheric dust.
4.1.4 Recording Maintenance
As the Home Service rovider, it is suggested that you record all routine maintenance and repairs
performed on the MARK 5 NUVO Lite unit, including hours and dates of service in Appendix 11 of this
manual and online at www.nidekmedical.com under the ‘Maintenance Log’ tab.
4.2 Cleaning Unit
eriodically, use a damp cloth to wipe down the exterior case of the MARK 5 NUVO Lite. If you use
medical disinfectants, be sure to follow manufacture’s instructions.
4.2.1 Preparing for New Patient Use
When you remove the MARK 5 NUVO Lite from a patient’s home, always dispose of the used nasal
cannula and humidifier bottle. Inspect the humidifier tube and clean or replace as needed.
Replace the cabinet air filter between each patient’s use or clean with warm soapy water if it is in good
condition. Clean this filter at least once per week or more frequently if operated in a dusty
environment.
Retest the MARK 5 NUVO Lite before you return it to your inventory.
5.0 Service
5.1 Components
The design of the Nidek Medical MARK 5 NUVO Lite Oxygen Concentrator allows for easy access and
removal of most components. This allows you to perform scheduled maintenance, repair, and
replacement of parts with minimal time and effort. The inlet air filter is conveniently located behind the
cabinet air filter on the upper cabinet back.
Caution: For your safety, be sure to set the I/0 (ON/OFF) switch to 0 (OFF) position and unplug the
power cord before you service the MARK 5 NUVO Lite Oxygen Concentrator.
Note: Record all scheduled maintenance on the Maintenance Log found in Appendix 10.
(Refer to Section 4.1.4)
5.2 Cabinet Removal
5.2.1 Removing Cabinet Back

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The cabinet back consists of a lower section and an upper section. Almost all maintenance functions
can be accomplished by removing only the upper section. Stand the device on its casters facing the
back. Remove five screws, two at the top near the handle and three near the bottom of the upper
section.
5.2.2 Caster Replacement
The casters are a push in type that does not require a fastener. Lay the device on its back to access
the casters from the bottom. ull them straight out away from the bottom.
5.3 Compressor
The compressor is the pump within the oxygen concentrator that supplies air to the separation process
performed by the sieve beds. The pressure generated by the compressor forces oxygen to flow out of
the top of the sieve columns. The compressor was designed to function without maintenance for
15,000 hours, after that time it should be either serviced or replaced.
The compressor is the likely cause of two potential specific problems:
a. An insufficient amount of air is supplied to the process, and
b. An excessive sound level.
 Air Supply
Compressor output refers to how much compressed air the compressor can produce. This depends
upon the model of the compressor, length of stroke, piston diameter, speed of rotation and condition of
seals. The cup seals form the seal between the piston and the cylinder wall. As the cup seals wear,
the output begins to gradually decrease.
This reduction in compressor output results in less air, and thus less oxygen, entering the sieve beds.
Therefore, the production of oxygen decreases. The minimum air volume required for full oxygen
capacity is 62 l/min (2.2 scfm) for 230 V devices (3 l/min units is 50l/min or 1.8 scfm) and 68 l/min (2.4
scfm) for 115 V devices, all tested at 20psi, 1.4 bar or 138 k a.
Because this drop in oxygen production occurs over a long period of time, preventive maintenance on
the compressor is not required until the recommended replacement period at 15,000 hours.
You can continue a patient’s therapy on the MARK 5 NUVO Lite unit as long as the oxygen
concentration level at the prescribed liter flow rate is within Nidek Medical’s specification limits. Refer
to Section 2.4.

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 Sound Level
The sound level is largely determined by the condition of the compressor’s bearings.
There are four bearings located within the compressor that allow the inner components of the
compressor to rotate. If the bearings wear to the point that they become loose and noisy, the
compressor becomes noticeably loud and needs servicing. The life of a compressor is determined
primarily by its operating temperature. It is extremely important that the inlet cooling air filters are
cleaned and replaced as required.
5.3.1 Compressor Replacement
Remove Compressor Assembly
To remove the compressor assembly for exchange, follow the steps listed below:
1. Set the unit’s I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power cord.
2. Remove the both the upper and lower cabinet back sections. Requires removal of nine
(9) screws.
3. Disconnect the suction tube and the discharge tube.
4. Disconnect the two compressor power cable leads and the two leads to the capacitor.
5. Slide the compressor assembly from the cabinet.
6. Remove compressor from the compressor support frame.
7. Remove heat exchanger from compressor.
8. Remove the heat exchanger fitting from the compressor.
Compressor Assembly Installation
To install a new compressor, follow the steps listed below:
C o m p re s s o r
P r e s s u re
F l o w
A ir
F ilte r
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
_ _ _ _ _ _ _
1 bar
P re s s u re
Gauge
A ir F lo w
M e te r
0 to 1 0 0 l/m in
R e s t ric to r

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1. erform the compressor removal procedure in reverse order.
2. Leak test all connections.
5.3.2 Capacitor Replacement
The capacitor helps the compressor to start and run more efficiently. If the compressor cannot start,
the capacitor may be defective and require replacement. The capacitor should be replaced at each
compressor service. To replace the capacitor, take the following steps:
1. Set the unit’s I/0 (ON/OFF) switch to the 0 (OFF) position, and unp ug the power cord.
2. Remove the upper cabinet back.
3. Disconnect the two eads to the capacitor and c ip the tie wrap securing the capacitor.
4. To insta the new capacitor, connect the eads and rep ace the capacitor and insta a
new tie wrap.
5. C ip excess after securing capacitor.
5.4 Process Control Valve
The MARK 5 NUVO Lite uses a solenoid powered poppet valve assembly to control the air separation
process. There is a feed port that connects to the compressor and an exhaust port that discharges
through an integral exhaust muffler. There are three possible valve states as follows:
1. Air feed connected to sieve bed A and exhaust connected to sieve bed B.
2. Air feed connected to sieve bed B and exhaust connected to sieve bed A.
3. Both ports open; this is a very short time period during which air
pressure bui ds in the sieve beds.
The control valve of the MARK 5 NUVO Lite requires no scheduled maintenance. If a valve does not
function as required, it is best to replace the complete sieve module as it is probable that one or both of
the beds has been damaged.
5.5 Sieve Bed Replacement
CAUTION:
Do not expose molecular sieve (contents of bed) to air for an extended period of time. rolonged
exposure of molecular sieve to the moisture in room air results in contamination and permanent
damage to the sieve material. Keep all openings to the sieve beds sealed during periods of storage.
 NOTE: It is recommended to replace the sieve beds and control valve as a
complete assembly.
5.5.1 Sieve Bed Removal
1. Set the unit’s I/0 (ON/OFF) switch to the 0 (OFF) position and unp ug the power cord.

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2. Remove the upper cabinet back.
3. Disconnect the compressor discharge 5/16” tube from the top of the so enoid va ve and
the product tube from the regu ator
4. Unp ug the so enoid va ve e ectrica eads at the so enoids
5. Lift the modu e up and out of the crad e.
5.5.2 Sieve Bed Installation
To install the sieve beds, follow the sieve bed removal procedure in reverse order. It is very important
to ensure that the tubes are fully inserted into the fittings to eliminate leaks.
To check for leaks, take the following steps:
1. P ug in the unit.
2. Set the unit’s I/0 (ON/OFF) switch to I (ON) for three minutes with the f ow meter c osed
to pressurize the system
3. App y soapy water around the tubing connections at the va ve; check for eaks.
Caution: There is an electrical shock hazard with the ower ON. Be careful that no water
contacts any of the electrical connections.
 NOTE: Even small leaks can affect concentrator performance and can cause
contamination of the sieve. Careful leak testing is important.
5. Cabinet Fan Replacement
The cabinet fan for the MARK 5 NUVO Lite is located adjacent to the compressor. Refer to the
troubleshooting chart in Section 6.0 of this manual for instances where replacement of the fan may be
required.
To replace the cabinet fan in the Mark5 Nuvo® unit, take the following steps:
1. Set the unit’s I/0 (ON/OFF) switch to the 0 (OFF) position and unp ug the power cord.
2. Remove the back cabinet.
3. Disconnect the fan eads.
4. Lift out the fan.
5. Insta iso ation foam around new fan.
6. Insert into cabinet and connect the fan eads.
7. Reinsta the back cabinet.
5.7 Circuit Board Replacement
There is but one printed circuit board within the MARK 5 NUVO Lite. It controls the alarm system
functions and also controls the timing logic for the solenoid valves. Consult the troubleshooting chart
in Section 6.0 to determine which and when to replace the printed circuit board.
CAUTION:
The rinted Circuit board ( CB) contain components that are sensitive to electrostatic discharge (ESD)
that can damage the board if not handled properly. As when handling any ESD sensitive CB, observe

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standard ESD safety procedures. These procedures include the following:
• Handle the CB by the edges only.
• Work on a grounded ESD mat.
• Wear a grounded wrist strap.
• Store CB in anti-static bags only.
5.7.1 Circuit Board Removal (Note that the Circuit Board on the OCSI unit is different to the
Circuit Board on the standard unit.)
1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power cord.
2. Remove the upper cabinet back.
3. Remove the flow control valve.
4. Disconnect the 7-pin connector from the upper circuit board.
5. Disconnect tubing from each end of the black sensor tube on the OCSI unit, 5. noting
their position and orientation.
6. Non OCSI units: Cut tie-wrap and remove pressure sensor line.
7. Remove the screws that attach the board to the front cabinet.
8. Remove the circuit board.
NOTE: Handle the new circuit board only by the edges to prevent electrostatic damage to the
unit.
For Reinstallation reverse the above procedure.
The printed circuit board includes two LED's that are visible inside the unit. They have been
added to assist the service technician in determining that the solenoid valves have power to them and
are cycling. Also, the new board flashes the green LED during the startup phase to indicate that the
device has power. The flashing green LED is continuous when oxygen concentration reaches the
specified level.
5.8 Product Regulator Check and Setting
The product regulator enables you to set the maximum flow of oxygen output by the MARK 5 NUVO
Lite unit. To check for proper adjustment of the product regulator, take the following steps:
1. Set the I/0 (ON/OFF) switch to the I (ON) position.
2. Allow the unit to run for a few minutes.
3. Connect a pressure gauge directly to the patient outlet.
4. The pressure should read 7.1 psig (49 k a) ± 10%.
5. If it requires adjustment, remove the upper cabinet back and lift out the module
enough to access the regulator.
6. Adjust the regulator as necessary. Turn the knob clockwise to increase the output pressure.
(Requires a 3/32 hex wrench)
7. Reinsert the module assembly and reinstall the upper cabinet back.
5.8.1 Product Regulator Cleaning or Rebuilding
Clean or rebuild the product regulator if the regulator cannot be adjusted.
I. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power cord,

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2. Remove the back cabinet.
3. Remove the regulator from the tee on top of the solenoid valve assembly.
4. Adjust the product regulator fully counterclockwise to unload the spring. This makes
disassembly and reassembly easier.
5. Remove the diaphragm. (Clean or replace it.)
6. Use a hex-head screwdriver to unscrew the diaphragm stem guide located in the center of the
regulator body to gain access to the seat,
7. Remove the seat. Be careful not to lose the spring located behind the seat.
8. Replace the seat or clean by blowing clean air on and around it.
9. With the spring behind the seat, screw the diaphragm stem guide back into the body of the
regulator. (Do not over tighten.)
10. Install a clean or replacement diaphragm.
11. ut the large spring and slip ring into the bonnet, and screw the bonnet onto the regulator
body.
12. Reinstall the regulator.
13 Reset the product regulator as described in Section 5.8.
5.9 Pressure Monitoring Board Replacement (Standard Unit, Non OCSI only)
The high and low pressure alarms are activated by a pressure transducer located on the printed circuit
board.
1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power cord.
2. Remove the upper cabinet back.
3. Disconnect the 7 pin connector from the circuit board.
4. Disconnect tubing from pressure sensor by cutting tie-wrap.
5. Remove the circuit board and replace with a new one.
6. Test the alarm system, as described in Section 2.3.
7. Reinstall the upper cabinet back.
5.10 Circuit Breaker Replacement
5.10.1 Circuit Breaker Removal
1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power cord.
2. Remove the upper cabinet back.
3. Disconnect the circuit breaker leads.
4. Unscrew the circuit breaker while you apply pressure to the circuit breaker retaining ring.
5.10.2 Circuit Breaker Installation
Follow the removal procedure for the circuit breaker in reverse order to install the new circuit breaker.
5.11. I/0 (ON/OFF) Power Switch Replacement
5.11.1 I/0 (ON/OFF) Power Switch Removal
1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position and unplug the power cord.
2. Remove both the upper cabinet back.

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3. Disconnect the I/0 (ON/OFF) switch leads from the back of the switch being careful to note the
position of each.
4. ush on the back of the power switch, while holding in its four retaining tabs, and remove the
switch through the front of the control panel.
5.11.2 I/0 (ON/OFF) Power Switch Installation
Follow the removal procedure for the I/0 (ON/OFF) power switch in reverse order to install a new power
switch.
5.12 Buzzer Replacement
The buzzer is a fixed component on the circuit board and is not individually replaceable.
5.13 Hour Meter Replacement
1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power cord.
2. Remove the upper cabinet back.
3. Disconnect the hour meter leads.
4. Remove the hour meter from the front cabinet.
5. Install the new hour meter into its mounting location. Make sure that the hour meter is mounted
right side up.
6. Reconnect the hour meter leads.
7. Reinstall the upper cabinet back.
5.14 Flow Valve Replacement
5.14.1 Flow Valve Removal
1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power cord.
2. Remove the upper cabinet back.
3. Remove the two hoses from the back of the flow valve.
4. Remove the knob from the flow valve, and the two hilips screws below the knob.
5. Remove the flow valve.
5.14.2 Flow Valve Installation
To install a new flow valve, follow the flow valve removal procedure in reverse order. Then
perform a leak test on the connections.
5.15 Power Cord Replacement
1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position and unplug the power cord.
2. Remove both the upper and lower cabinet back sections. Clip the power cord retaining tie wrap
3. Slide the power cord strain relief reinforcement upwards to remove it from the mounting location
at the bottom of the front cabinet.
4. Disconnect the power cord leads from the terminal quick connects.
5. Connect the leads on the new power cord at the terminal quick connects.
6. Reinstall the power cord strain relief into the base of the unit.
Reconnect the upper cabinet back and install a new power cord retaining tie wrap.

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.0 Troubleshooting
.1 Air Pressure Test (P1)
Testing the operating pressure is a useful diagnostic tool when a concentrator has low purity
and requires servicing. Units functioning normally do not require operating tests.
Use the following procedure to test the operating pressure of the unit.
1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power cord.
2. Remove the cabinet rear
3. Remove the air supply tubing going to the control valve and install the test
port tee fitting. Figure 6.1.1 shows the normal operating configurations for each type of unit.
Figure 6.1.2 shows the installation of the test ports.
4. Connect the pressure test gauge to the test port.
5. lug in the power cord, and set the I/0 (ON/OFF) power switch to the ON position. Set the flow
selector knob to 5 l/min, and allow the unit to run at least five minutes.
6. Observe the maximum and minimum readings on the pressure test gauge.
7. The maximum reading should not exceed 34 psig (235 k a) (25 psig/172 k a for 3 l/min units).
The minimum reading should not be less than 10 psig (70 k a) (8 psig/ 55 k a for 3 l/min
units).
NOTE When you turn the unit on, it will take several minutes to reach normal operating
pressures.
Figure .1.1 Normal Operating Configuration
INLET FROM
COMPRESSOR
PRODUCT OUT TO
FLOW CONTROL
VALVE