Nidek Mark 5 Nuvo Service manual

Nidek Medical Products, Inc®
Mark5 Nuvo® [M5C5] Oxygen
Concentrator Service Manual

Nidek Medical Products, Inc. 3949 Valley East Industrial Drive

Birmingham, Alabama 35217 USA

Telephone: [phone] • 24-Hour Fax: [phone]

Nidek Medical is a trademark of Nidek Medical Products, Inc.

Mark5 Nuvo® and M5C5 are registered trademarks of Nidek Medical Products, Inc.

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Table of Contents

General Safety

Instructions

Section 1.0

Introduction

1.1

1.2

1.3

Section 2.0

Operational Check and Concentration Test

2.1

Section 3.

0

Patient Instructions

3.1

Section 4.0

Home Service Provider Maintenance

4.1

4.2

Section 5.0

Service

5.1

5.2

3-5

Production and Use of Oxygen 6
Use and Maintenance of the Device 6
Standards and Regulations 6

Home Service Provider Responsibility 7
Important Notice and Symbol Explanations 8
Functional Specifications 9

2.2

2.3

2.4

3.2

Description of Operation
Operation Check
Alarm System

2.3.1 Battery Test

2.3.2 Power Failure Alarm test
Oxygen Concentration Test and Specification

General Instructions
Routine Maintenance by the Patient

3.2.1 Cleaning the Cabinet Air Filter

3.2.2 Checking the Alarm System Battery

Routine Maintenance 13

4.1.1 Cabinet Air Filter 13

4.1.2 Final Product Filter Replacement 13

4.1.3 Inlet Air Filter Replacement 14

4.1.4 Battery Replacement 14

4.1.5 Wick Replacement 14

4.1.6 Recording Maintenance 15
Cleaning and Infection Control 15

4.2.1 Preparing for New Patient Use 15

10
10
11
11
11

12
12
12
13

9

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Components 16
Cabinet Removal 16

5.2.1 Removing Cabinet Back 16

5.2.2 Removing Cabinet Front 16

5.2.3 Removing Control Panel 16

5.2.4 Main Structure 16

5.2.5 Caster Replacement 17

5.3

5.4

5.5

5.

6

5.7

5.8

5.9

5.10

5.11

5.12

5.13

5.14

5.15

6.1

6.2

6.3

6.4

6.5

Compressor 17

5.3.1 Compressor Replacement 18

5.3.2 Capacitor Replacement 19
Process Control Valve 19

Sieve Bed Replacement 19

5.5.1 Sieve Bed Removal 20

5.5.2 Sieve Bed Installation 20
Cabinet Fan Replacement 20
Circuit Board Replacement 21

5.7.1 Circuit Board Removal 21

5.7.2 Circuit Board Installation 22
Product Regulator Check and Setting 22

5.8.1 Product Regulator Cleaning or Rebuilding 22
Pressure Switch Replacement 23
Circuit Breaker Replacement 23

5.10.1 Circuit Breaker Removal 23

5.10.2 Circuit Breaker Installation 23
I/0 (ON/OFF) Power Switch Replacement 23

5.11.1 I/0 (ON/OFF) Power Switch Removal 23

5.11.2 I/0 (ON/OFF) Power Switch Installation 24
Buzzer Replacement 24
Hour Meter Replacement 24
Flow Meter Replacement 24

5.14.1 Flow Meter Removal 24

5.14.2 Flow Meter Installation 24
Power Cord Replacement 24

Section 6.0
Troubleshooting

Air Pressure Test (P1) 25

6.1.1 High Air Pressure 25

6.1.2 Low Air Pressure 26
Product Pressure Test (P2) 26

6.2.1 High Product Pressure 26

6.2.2 Low Product Pressure 27
General Troubleshooting 27
Troubleshooting Chart 28-32
Tool Kit and Pressure Test Gauge 33

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Appendices

Exploded

Parts Listing

Maintenance

Drawings

A1: Base Assembly
A1.1: Base Assembly
A2: Main Structure Assembly – Front View 36
A3: Main Structure Assembly – Rear View 37
A4: Regulator Assembly 38
A5: Compressor Assembly
A5.1: Compressor Assembly
A6: Control Panel Assembly; OCSI Unit - Front 41
A7: Control Panel Assembly; OCSI Unit - Rear 42
A6.1: Control Panel Assembly; OCSI Unit - Front 43
A7.1: Control Panel Assembly; OCSI Unit - Rear 44
A8: Control Panel Assembly; Non OCSI Unit ­Front
A9: Control Panel Assembly; Non OCSI Unit –
Rear
A10: Air Tank Assembly 47
A10.1: Air Tank Assembly 48
A11: Front Cabinet Assembly 49
A11.1: Front Cabinet Assembly 50
A12: Rear Cabinet Assembly 51
A12: Rear Cabinet Assembly 52
A13: Module Assembly 53

34
35

39
40

45
46

Record

A14: Replacement Parts Listing 54-57
A15: Maintenance Log 58-59

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General Safety Instructions

Production and use of oxygen

Oxygen is not a flammable gas, but accelerates the combustion of materials. To
prevent fire risks, the MARK5 NUVO should be kept away from flames,
incandescent sources or sources of heat (cigarettes) and combustible products
such as oil, grease, solvents, aerosols, etc.

Do not use in an explosive atmosphere.
Prevent 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 gas generated 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
manufacturers plate on the rear of the appliance.

Do not use an extension cord or multiple sockets which can create sparks and
therefore pose a fire risk.

Use of the MARK5 NUVO must be restricted solely to oxygen therapy on medical
prescription in compliance with the daily 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 MARK5 Nuvo has an audible alarm intended to warn the user of any
problems. The user must determine the maximum distance away from the
Nuvobased on the on the sound levels in the environment, to ensure that the
alarm is always audible.

Standards & Regulations
In compliance with UL60601-1 [EN60601-1] (para 6.82.b):

“The manufacturer, assembler, installer or importer are not considered to be
responsible for consequences or the safety, reliability and characteristics of a
device unless,

● the assembly, extensions, adjustments modifications or repairs have been

performed by persons authorized by the manufacturer,
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● the electrical installation of the corresponding premises complies with appropriate

regulations and codes,

● the device is used in accordance with the instructions for its use.

If the replacement parts used for periodic servicing by an approved technician do
not comply with the manufacturer’s specifications, the manufacturer is absolved of
all liability in the event of an incident.

Do not open the equipment when it is powered on: risk of electrocution.
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 the 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.

1.0 Introduction

1.1 Home Service Provider Responsibility

All Home Service Providers of the Nidek Medical Mark5 Nuvo® Oxygen
Concentrator must assume responsibilities for handling, operational check-out,
patient instruction, and maintenance. These responsibilities are outlined below and
throughout this manual.

WARNING

Mark5 Nuvo units must not be used for or with any life-supporting or life sustaining
applications. Patients unable to communicate discomfort while using this device
may require additional monitoring. Advise patients to immediately notify their Home
Service Provider(s) and/or physician(s) in case of an alarm or any discomfort.

As a Home Service Provider, you must do all of the following:

● Inspect the condition of each Mark5 Nuvo® unit immediately upon

delivery to your business location. Note any sign of damage, external or
internal, on the delivery receipt, and report it directly to both the freight
company and Nidek Medical Products, Inc. immediately.

● Check the operation of each Mark5 Nuvo® before delivery to a patient.

Always operate the unit for a reasonable length of time and check that the
oxygen concentration level is within specifications as referred to in
Section 2.4. Test the battery and power disconnect alarm as described in
Section 2.3 of this manual.

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● Deliver Mark5 Nuvo® units only to patients authorized by a physician’s

hazard or unsafe practice that can result

Describes a hazard or unsafe practice that can result

Provides information important enough to emphasize

prescription. The Mark5 Nuvo® must not be used as a life-supporting or
life sustaining device. A backup supply of oxygen must be available.

● Instruct patients how to use the Mark5 Nuvo® in conjunction with the

Patient Manual.

● Instruct patients to notify their physicians and/or Home Service Providers

if they experience any signs of discomfort.

● Instruct each patient how to perform routine maintenance of the cabinet

air filter and how to check the alarm system battery. (Refer to Section

3.2.)
Be available to service each patient at any time. Maintain the Mark5
Nuvo® 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 Mark5 Nuvo® Oxygen Concentrators.

● Refer to the Mark5 Nuvo® Product 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:

CAUTION:

NOTE:

The following harmonized symbols (pictograms), used for non-English language
countries, will be located on the exterior of the Mark5 Nuvo® unit:

Read the accompanying documents; particularly the patient
operating guide.

Store, ship and use the device in an upright condition.

Describes a
in severe bodily injury or death.

in minor bodily injury or property damage.

or repeat.

No smoking within five feet of this device, oxygen-carrying tubing, or
accessories.

Indicates an alarm signal.

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Do not use any oil or grease on or near the device

1.3 Functional Specifications

Dimensions: 15.5 in. long, 15.6 in. wide, 27.8 in. tall
(394 mm long, 396 mm wide, 706 mm high)

Weight: 50 to 54 Ib (22.5 to 24.5 kg) depending on sound attenuation;
Electrical 120 VAC, 60 Hz, 4 amps, 410 watts

Requirements: 220 VAC, 50 Hz, 2 amps, 420 watts
Capacity: 5 liters per minute at 90% oxygen

(Based on 70°F [21°C] at sea level)
Accuracy: Flow meter ±5% full scale. (Based on pre-calibrated analysis.)
Concentration: 1 - 3 liters per minute at 95% + 0.5 / - 3%

4 liters per minute at 92% + 3.5 / - 3%
5 liters per minute at 90% + 5.5 / - 3%

Response Time: Acceptable concentration is normally achieved in about

90 seconds; allow 5 minutes to attain full concentration.

Positioning: Operate the unit in an upright position, maintaining at

least six inches of open space on all sides for ventilation.

2.0 Operational Check and Concentration Test

2.1 Description of Operation

Air enters the Mark5 Nuvo® Oxygen Concentrator through an external cooling air
intake filter. This filtered air enters the compressor via a suction resonator and fine
filter, which quiets the suction sounds made by the compressor. Pressurized air
then exits the compressor and passes through a heat exchanger into an air tank.
The heat exchanger reduces the temperature of the compressed air and the air tank
stores air when feed is interrupted. Next, a rotary poppet feed 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 four seconds
and delivers it to the product storage volume in the end of the column. Oxygen exits
the adsorbent column through a pressure regulator, flow control valve, flow meter,
and final product filter. The flow control valve, which is part of the flow meter,
controls the flow rate of oxygen delivered to the patient. The Mark5 Nuvo® unit
2010-2225 Rev - B Page 9 of 59

delivers up to 95% oxygen concentration at flow rates from 1 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 Mark5
Nuvo® Oxygen Concentrator thoroughly after manufacture before releasing for
shipment. As the home service provider, 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.

● Before plugging the unit into the wall outlet, actuate the I/0

(ON/OFF) switch to the I (ON) position and note that the audible
alarm sounds continuously. (See Section 2.3). Move the switch to
the 0 (OFF) position.

2. Plug 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:

● The compressor runs, listen for the sound.

● Exhaust air flows out of the bottom of the unit.

● OPTIONAL for Units Equipped with Oxygen Concentration Status

Indicator (OCSI): The OCSI green light remains off until the oxygen
concentration reaches 85% ± 3% (82% ± 2% for 50 Hz units)
(approximately two minutes).

3. Turn the flow meter adjustment knob counterclockwise until it stops

(wide open). The flow meter should register in excess of 5.5 liters/min.
If not, refer to Section 5.8 to adjust the product regulator.

4 Perform an oxygen concentration test, as described in Section 2.4.

2.3 Alarm System

The Mark5 Nuvo® Oxygen Concentrator is equipped with a battery-powered alarm
system, which sounds a continuous and loud alarm when a power failure occurs or
when one or 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,

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2.3.1 Battery Test

The Mark5 Nuvo® battery can be checked by observing that the continuous alarm
sounds when the I/0 (ON/OFF) switch is moved to the I (ON) position when the unit
is unplugged from the wall outlet.

2.3.2 Power Failure Alarm Test

To test the power failure alarm, perform the following actions:
Unplug the power cord from the wall outlet, and set the I/0 (ON/OFF) switch to the I

(ON) position.
This should immediately activate the 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 Providers, based on their expertise and
documentation, may establish and implement their own plans for checking oxygen
concentration. The interval established may be longer or shorter than 90 days,
which is Nidek Medical’s default time period for providers who do not choose to
establish their own plan.

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 meter adjustment knob to the prescribed flow rate.

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.

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Nidek Medical Mark5 Nuvo® Concentration Specifications

air filter from the back of the

with household

Reinstall the clean air filter on the grille in the back of

Liter Flow Specification Within Specification
1 to 3 l/min 95% + 0.5 / - 3% 92% or higher
4 l/min 92% + 3.5 / - 3% 89% or higher
5 l/min 90% + 5.5 / - 3% 87% or higher

3.0 Patient Instructions

3.1 General Instructions

It is important that patients thoroughly understand how to operate the Nidek Medical
Mark5 Nuvo® 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 alarms, they must notify
their Home Service Provider and/or physician immediately. You, as the Home
Service Provider, are responsible to see that each patient receives the Patient
Manual. Explain each step in the operation of the unit to the patient in reference to
this manual.

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 battery

3.2.1 Cleaning the Cabinet Air Filter
NOTE:

The patient must clean this filter weekly, as described below. The filter
may require daily cleaning if the Mark5 Nuvo® 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

Mark5 Nuvo® unit.

2 Wash the dirty filter in warm water

detergent, and rinse.
3 Use a soft absorbent towel to remove excess water.
4

the unit.

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3.2.2 Checking the Alarm System Battery

See Procedure described in Paragraph 2.3.1

4.0 Home Service Provider Maintenance

4.1 Routine Maintenance

The Mark5 Nuvo® unit has two filters and a 9-volt battery that require scheduled
maintenance and replacement.

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 Providers, based on their expertise and
documentation, may establish and implement their own practices for checking
oxygen concentration. Consult Nidek Medical’s Service and Maintenance Log (A-

15) for the recommended intervals for testing.
Nidek Medical does not require preventive maintenance on the concentrator. You

do not need to perform any maintenance as long as the Mark5 Nuvo® unit remains
within specifications at the prescribed flow rate. (Refer to Section 2.4)

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 Mark5 Nuvo® 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 unplug the power
cord.

2. Remove the cabinet back to locate the final product filter.

NOTE: Observe the position of the filter 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. Push
the tubing together so that it overlaps the barbs of the final product filter

2010-2225 Rev - B Page 13 of 59

connections.

5. Record information about the final product filter replacement in Appendix 15
of this manual and online at www.nidekmedical.com under the ‘Maintenance
Log’ tab.

6. Reinstall the cabinet back.

4.1.3 Inlet Air Filter Replacement

The inlet air filter requires inspection at each patient visit. The filter should be
replaced annually, 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 rear cabinet access panel 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 15 of this

manual and online at www.nidekmedical.com under the ‘Maintenance Log’
tab.

5. Reinstall the access panel.

4.1.4 Battery Replacement

Each time the standard Mark5 Nuvo® unit is turned on, the alarm must sound loudly
for approximately five seconds to indicate a good battery. An alarm that does
anything other than sound loudly for five seconds indicates a weak battery and
requires replacement. For units with OCSI, actuate the switch with the power cord
unplugged to test the battery.
To replace the battery, take the following steps:

1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power

cord.

2. Remove the access panel in the cabinet back.

3. Pull the battery from the mounting slot and remove the connection wires.

4. Attach the new battery to the connector and reinsert it into the mounting slot.

5. Set the I/0 (ON/OFF) switch to the I (ON) position to test the alarm.

6. Record the battery replacement information in Appendix 15 of this manual

and online at www.nidekmedical.com under the ‘Maintenance Log’ tab.

7. Reinstall the access panel.

4.1.5 Wick Replacement

The wick is installed in the process air stream of the unit, connected to the air tank,
to assist with removal of moisture from the air. This helps prevent premature
contamination of the sieve beds, particularly in humid climates. The wick should be
replaced at each compressor service / module replacement; it is suggested that
more frequent replacement be done in very humid climates. The wick is located in
a bushing located just to the right of the gearmotor. It is installed in a quick release
fitting. Pull the fitting from the bushing by hand – it may require several pounds of
force, remove the wick and install a new one in its place. Re-insert the wick end
and fitting into the bushing so the wick is totally below the base plate surface.

Page 14 of 59 2010-2225 Rev - B

4.1.6 Recording Maintenance

As the Home Service Provider, it is suggested that you record all routine
maintenance and repairs performed on the Mark5 Nuvo® unit, including hours and
dates of service in Appendix 15 of this manual and online at www.nidekmedical.com
under the ‘Maintenance Log’ tab.

4.2 Cleaning and Infection Control

With the growing concern about possible cross infection from home oxygen
equipment (i.e.. oxygen concentrators) from one home care patient to another,
appropriate cautions should be exercised.

The organisms of most concern are M. Tuberculosis, HIV, and Viral Hepatitis.
These are potentially pathogenic.

Tuberculosis can survive outside of the human body, but its mode of transmission is
by droplet nuclei. When infected individuals cough, they release droplet nuclei into
the air, and these carry the Tuberculosis organism. Another person may breathe in
these droplet nuclei, but prolonged exposure to the infected person is usually
necessary for infection to occur.

HIV and Viral Hepatitis are both viruses, which are not living cells themselves but
which can duplicate when in a living “host” cell. Both of these organisms are usually
passed on by person-to-person contact, and both need to be in the human body to
survive. Once outside the body, viruses can survive for only a short period of time.

4.2.1 Preparing for New Patient Use

When you remove the Mark5 Nuvo® from a patient’s home, always dispose of the
used nasal cannula and humidifier bottle. Clean the exterior of the Mark5 Nuvo®
with a soapy water solution or commercial detergent cleaner to remove any gross
debris, organic or otherwise. Be careful not to get any liquid into the interior of the
unit.

Next, clean the exterior with either a common chemical disinfectant or a bleach
solution* and allow it to air dry. For the bleach solution, wear eye and skin
protection to prevent exposure to the chlorine. Retest the Mark5 Nuvo® before you
return it to your inventory.

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.

*Make the bleach solution a 1:100 dilution of 5.25% sodium hypochlorite. Mix one
part household bleach (e.g. Clorox) with 99 parts cold tap water. To measure the

2010-2225 Rev - B Page 15 of 59

solution easily, take 1/4 cup of household bleach, and mix it with a gallon of cold tap
water. Allow the mixture to sit on potentially contaminated surfaces for 10 minutes.

5.0 Service

5.1 Components

The design of the Nidek Medical Mark5 Nuvo® 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 and battery are conveniently located inside the small
access panel in the cabinet back.

CAUTION:

For your safety, be sure to set the I/0 (ON/OFF) switch to the 0 (OFF)
position and unplug the power cord before you service the Mark5 Nuvo®
Oxygen Concentrator.

NOTE: Record all scheduled maintenance. (Refer to Section 4.1.6.)

5.2 Cabinet Removal

5.2.1 Removing Cabinet Back

To remove the cabinet back, remove two screws near the base (one on each side)
and two inset screws at the top just under the handle.

5.2.2 Removing Cabinet Front

To remove the cabinet front, remove two screws near the base (one on each side)
adjacent to the rear cabinet screws and two inset screws at the top just under the
handle. It is necessary to remove the cabinet back to access the top screws.

5.2.3 Removing Control Panel

Eight screws hold the control panel in place; the front cover must be removed to
access these screws. It is necessary to remove the electrical wiring and pneumatic
tubing to fully release the control panel.

5.2.4 Main Structure

The weight and forces of the internal components rest solely on four parts: the main
structure, the compressor plate, the base-plate and the base. These parts were
specially designed and formed. They should never require replacement under
normal use.

Page 16 of 59 2010-2225 Rev - B

5.2.5 Caster Replacement

The casters are a push in type that does not require any fastener. Lay the device
on its back to access the casters from the bottom. Pull 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 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.

Because this drop in oxygen production occurs over a long period of time,
preventive maintenance on the compressor is not required.

You can continue a patient’s therapy on the Mark5 Nuvo® 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.

2010-2225 Rev - B Page 17 of 59

_______
_______
_______
_______
_______
_______

0 to 100 l/min

_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______

Air Flow

Meter

Pressure

1 bar

Pressure

Gauge

Flow

Compressor

Restrictor

Air

Filter

● 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 cabinet 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 cabinet back and front.

3. Disconnect the suction tube.

4. Disconnect the two compressor power cable leads and the two leads to the
capacitor at the inline connector.

5. Remove the three screws that connect the compressor plate to the base of
the unit, lift and slide out the compressor assembly.

6. Remove compressor from the plate by removing the four compressor bolts.

7. Remove tie wrap from compressor plate wiring harness.

8. Remove the heat exchanger tubing and fittings.

Page 18 of 59 2010-2225 Rev - B

Compressor Assembly Installation
To install the rebuilt compressor assembly, follow the steps listed below:

1. Perform 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 / module
replacement. To replace the capacitor, take the following steps:

1. Set the unit’s I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug
the power cord.

2. Remove the rear and front cabinets.

3. Disconnect the two leads to the capacitor and remove the nut from the
mounting screw.

4. Remove the nut and washer below the capacitor.

5. To install the new capacitor, connect the leads and replace the capacitor and
associated hardware.

5.4 Process Control Valve

The Mark5 Nuvo® uses a gearmotor powered rotary cam-operated poppet valve
assembly to control the air separation process. There is a feed port that connects
to the air tank and an exhaust port that connects to the 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 closed; this is a very short time period during which air pressure
builds in the air tank.

The control valve of the Mark5 Nuvo® unit 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. Prolonged 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.

2010-2225 Rev - B Page 19 of 59

NOTE

If replacement is necessary, you must replace both sieve beds at the same time. It
is recommended to replace the sieve beds and control valve module 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 unplug the
power cord.

2. Remove the cabinet back.

3. Disconnect the 1/4-inch product tube from the top of one of the beds.

4. Remove the 4 tie-wraps ( 2 from each sieve bed ). Note their position and
orientation.

5. Remove two “Z” brackets; one from the top of each of the sieve beds.

6. Lift the module up and out of the base plate cradle.

7. Unplug the valve gearmotor electrical leads at the in-line connections.

8. Manipulate the module so that the black exhaust hose can be removed from
the fitting on the valve.

9. Loosen the hose clamp and remove the black feed hose from the fitting on
the valve.

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 tighten all tubes to eliminate leaks. However, do not over
tighten.

To check for leaks, take the following steps:

1. Plug in the unit.

2. Set the unit’s I/0 (ON/OFF) switch to I (ON) for three minutes with the

flowmeter closed to pressurize the system.

3. Apply soapy water around the hose connections at the valve and the

air tank; check for leaks.
Caution: There is an electrical shock hazard with the Power 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.

5.6 Cabinet Fan Replacement

The cabinet fan for the Mark5 Nuvo® is located under 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 unplug the

Page 20 of 59 2010-2225 Rev - B

power cord.

2. Remove the front and back cabinets.

3. Follow the procedure in 5.3.1 to remove the compressor assembly.

4. Disconnect the fan leads.

5. Position the new cabinet fan so that the air flow arrow points toward the
bottom and the electrical connections. Be sure that the electrical wires do
not interfere with the rotation of the fan.

6. Connect the fan leads and place the fan on the mounting pins.

7. Replace compressor assembly.

8. Reinstall the front and back cabinets.

5.7 Circuit Board Replacement

The printed circuit board controls the alarm system functions.
Consult the troubleshooting chart in Section 6.0 to determine when to replace the

printed circuit board.
CAUTION
The Printed Circuit Board (PCB) contain components that are sensitive to

electrostatic discharge (ESD) that can damage the board if not handled properly. As
when handling any ESD sensitive PCB, observe standard ESD safety procedures.
These procedures include the following:

• Handle the PCB by the edges only.

• Work on a grounded ESD mat.

• Wear a grounded wrist strap.

• Store PCB 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 front and cabinet backs.

3. Remove the control panel to which the circuit board is attached.

4. Disconnect the 7-pin connector from the circuit board.

5. Disconnect tubing from each end of the black sensor tube on the OCSI unit,
noting their position and orientation.

6. Non OCSI units: Cut tie-wrap and remove pressure sensor line.

7. Remove three screws that attach the board to the control panel.

8. Remove the circuit board.
NOTE: Handle the new circuit board only by the edges to prevent

electrostatic damage to the unit.

5.7.2 Circuit Board Installation

2010-2225 Rev - B Page 21 of 59

1. Locate the circuit board to line up the attachment points.

2. Install the three mounting screws.

3. Reinstall the tubing to each end of the black sensor tube as it was before.

4. Non OCSI unit: Reinstall the pressure sensor line and tie-wrap.

5. Plug in the 7-pin connector.

6. Reinstall the control panel and the front and cabinet backs.

5.8 Product Regulator Check and Setting

The product regulator enables you to set the maximum flow of oxygen output by the
Mark5 Nuvo® 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 ± 10% psig (50 ± 10% kPa).

5. Adjust the regulator if necessary. Turn the knob clockwise to increase the
output pressure. (Requires a 5/32 hex wrench)

6. Reinstall the cabinet front and cabinet backs.

5.8.1 Product Regulator Cleaning or Rebuilding

Clean or rebuild the product regulator if the flow meter ball fluctuates more than 1/4
of a liter or if the regulator cannot be adjusted.

I. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power

cord,

2. Remove the front and rear cabinets.

3. Use large pliers to unscrew the mounting nut of the product regulator.
Remove from the main structure.

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. Put the large spring and slip ring into the bonnet, and screw the bonnet onto
the regulator body.

12. Reinstall the regulator, mounting it securely to the main structure.

13. Reset the product regulator as described in Section 5.8.1.

5.9 High or Low Pressure Switch Replacement (Standard Unit, Non OCSI

only)

Page 22 of 59 2010-2225 Rev - B

The high and low pressure alarms are activated by a pressure transducer located
on the circuit board adjacent to the mains switch.

1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power
cord.

2. Remove the back and front cabinets and the control panel.

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 control panel and the front and back cabinets.

5.10 Circuit Breaker Replacement

5-10.1Circuit Breaker Removal

1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power
cord.

2. Remove the cabinet front.

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 front and back covers.

3. Unscrew the eight Phillips-head screws that hold the control panel to the
main structure.

4. Disconnect the I/0 (ON/OFF) switch leads from the back of the switch being
careful to note the position of each.

5. Push 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.

2010-2225 Rev - B Page 23 of 59

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 cabinet back.

3. Disconnect the hour meter leads.

4. Push hour meter mounting tabs inward from the hour meter.

5. Remove the hour meter from the main structure.

6. Install the new hour meter into its mounting location, and push the mounting
tabs outward to secure hour meter. Make sure that the hour meter is
mounted right side up.

7. Reconnect the hour meter leads.

8. Reinstall the cabinet back.

5.14 Flow Meter Replacement

5.14.1 Flow Meter Removal

1. Set the I/0 (ON/OFF) switch to the 0 (OFF) position, and unplug the power
cord.

2. Remove the cabinet back and front and then the control panel. Ref. 5.2.3.
On units with OCSI, it is necessary to also first remove the circuit board.

3. Remove the 3/8-inch silicone oxygen tubing from the flow meter fittings.

4. Unscrew the flow meter nuts with a wrench.

5. Remove the flow meter through the control panel.

5.14.2 Flow Meter Installation

To install a new flow meter, follow the flow meter 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 the cabinet back and front.

3. Slide the power cord strain relief reinforcement upwards to remove it from the
mounting location at the rear of the base.

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.

7. Reconnect the front and cabinet backs.

Page 24 of 59 2010-2225 Rev - B

6.0 Troubleshooting

6.1 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 test port plug at the top of the air tank.

4. Connect the pressure test gauge to the test port.

5. Plug in the power cord, and set the I/0 (ON/OFF) power switch to the ON
position. Set the flow meter 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 kPa). The minimum
reading should not be less than 16 psig (110 kPa).

NOTE: When you turn the unit on, it will take several minutes to reach
normal operating pressures.

6.1.1 High Operating Air Pressure

Higher than normal operating pressure may indicate any of the following:

► A restrictive exhaust muffler, which does not allow the waste (purge) gas

to exit the system freely.
Operate the unit with the exhaust muffler disconnected to see if the

operating pressure returns to normal.

► An improperly operating control valve, confirm that the control valve is

turning at 4 rpm. Time the exhaust pulse at 7.5 seconds.

► Contaminated sieve beds. Change the sieve beds.

6.1.2 Low Operating Air Pressure

2010-2225 Rev - B Page 25 of 59

Lower than normal operating pressure may indicate any of the following:

► A restriction in the suction resonator or inlet air filter, which limits the

amount of room air available to the compressor. Disconnect the suction
tube at the compressor, and allow the unit to operate without the suction
resonator to see if normal operating pressure returns.

► An improperly operating control valve. Confirm that the control valve does

not have a leak.

► A leak in the unit, which allows system pressure to escape. Leak test the

unit.

► A compressor with reduced output.

Ensure that the concentration level at the desired liter flow is within specifications
listed in section 2.4. If it is below specifications, replace or repair the compressor.

6.2 Product Pressure Test (P2)

Testing the product 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 product 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 test port plug from the tee at the top of the sieve bed.

4. Note: The standard unit without OCSI does not have a test port; use the
pressure sensor tube as the test connection.

5. Connect the pressure test gauge to the P2 test port.

6. Plug in the power cord, and set the I/0 (ON/OFF) power switch to the ON
position. Set the flow meter to 5 l/min, and allow the unit to run at least five
minutes.

7. Observe the maximum and minimum readings on the pressure test gauge.
The maximum reading should not exceed 16 psig (110 kPa). The minimum
reading should not be less than 9 psig (62 kPa).

6.2.1 Low Product Pressure

Lower than normal operating pressure may indicate any of the following:

► An inlet air filter that limits the amount of room air available to the

compressor. Disconnect the suction tube at the compressor, and allow
the unit to operate without the suction resonator to see if normal operating

Page 26 of 59 2010-2225 Rev - B

pressure returns.

► An improperly operating control valve. Confirm that the control valve does

not have a leak.

► A leak in the unit, which allows system pressure to escape. Leak test the

unit.

► A compressor with reduced output. Ensure that the concentration level at

the desired liter flow is within specifications listed in Section 2.4. If it is
below specification, replace or repair the compressor.

6.2.2 High Product Pressure

Higher than normal operating pressure may indicate any of the following:

► A restrictive exhaust muffler, which does not allow the waste (purge) gas

to exit the system freely.

► Operate the unit with the exhaust muffler disconnected to see if the

operating pressure returns to normal.

► Check exhaust muffler and hoses for any restrictions.

► An improperly operating control valve, confirm that the control valve is

turning at 4 rpm. Time the exhaust pulse at 7.5 seconds.

► Contaminated sieve beds. Change the sieve beds.

6.3 General Troubleshooting

Before reviewing the troubleshooting chart, the following steps may be useful to
isolate any malfunctions:

1. Turn the concentrator on. If unit does not turn on, refer to troubleshooting
chart.

2. Make sure all filters are clean.

3. Turn flow meter completely open, up to the highest setting. The ball should
rest at the top of the scale. If setting is not greater than 5.5 l/min, adjust
regulator so that the ball level exceeds 5.5 l/min with the flow meter
completely open.

4. Connect test pressure gauge to the outlet fitting of the unit. The pressure
should read approximately 7 psig (50 kPa).

5. Connect test pressure gauge to the P1 test port on the air tank. The
pressure should be cycling between approximately 16 and 34 psig (110 and
235 kPa).

6. Make sure the unit is cycling properly by observing the pressure gauge cycle

2010-2225 Rev - B Page 27 of 59

between a high and a low pressure. If the unit is not cycling properly, refer to
troubleshooting chart.

7. Make sure that the unit is leak free by testing all tubing connections and
fittings with leak testing solution. Protect circuit board from solution and start
leak test at the heat exchanger, following the air flow through the unit to the
oxygen outlet. Repair all leaks by tightening connections and fittings.

8. Set the concentrator at 5 l/min and connect pressure test gauge to P2 at the
top of the sieve beds. Determine pressure parameters by observing high
and low pressure points on the gauge. It should cycle between
approximately 9 psig and 16 psig (62 to 110 kPa). If pressures are high or
low, refer to the troubleshooting chart.

9. Review troubleshooting chart to isolate and repair any other malfunctions.
The following diagnostic flow chart will help to isolate potential problems.

Page 28 of 59 2010-2225 Rev - B

LowOxygen

Concentration

Verify Oxygen

Flow Rate

Measure Air

Pressure

Low Pressure High Pressure

Replace Air

Inlet Filter

Check for

Leaks

Check the

Compressor

Normal Air

Pressure

Measure the

Oxygen Pressure

Low Pressure High Pressure

Check for

Leaks

Replace

Wick

Replace

Muffler
Foams

Check

Control

Valve

Replace

Muffler
Foams

Check the

Control

Valve

Normal Pressure

Check for leaks at the:

- regulator outlet

- product tubing

- oxygen outlet

Replace

Sieve

Module

2010-2225 Rev - B Page 29 of 59

6.4

Troubleshooting Chart

Problem

Probable

Cause

Solution

Compressor does not run.

onnections

No power to unit.

Check wall outlet for power.

Constant audible alarm with
I/0 (ON/OFF) power switch
in ON position.

Compressor runs with
intermittent alarm.
Concentration at 5 L/MIN is
within specifications.
Compressor shuts down
intermittently,

Unit circuit breaker tripped
or faulty.

Faulty electrical
connections. Defective
circuit board.

Defective I/0 (ON/OFF)
power switch.

Defective high or low
pressure switch.
Kinked tubing.

Restricted air flow through
unit.

Unit overheating due to
improper location.

Reset or replace circuit
breaker.

Check electrical
connections.

Check power switch.
Replace I/0 (ON/OFF)
power switch.
Replace and retest pressure
switch.
Check tubing that joins the
tops of the sieve beds.
Clean inlet air filter, or
remove obstruction.

Locate unit away from
heating source, providing
adequate ventilation on all
sides.

Defective cabinet fan.

Compressor does not start.
I/0 (ON/OFF) power switch
in ON position, intermittent
alarm, and cabinet fan turns.

Compressor runs with
intermittent low pressure
alarm and low oxygen
concentration.

Page 30 of 59 2010-2225 Rev - B

Extreme cold start.

Compressor thermally cut
off due to excessive heat.
NOTE: It will not restart unit
it cools down,

Defective capacitor.
Faulty electrical connection

for compressor.
Leak Leak test and repair leak.

Replace cabinet fan.
Allow unit to reach room

temperature.
Blocked air intake or

defective cabinet fan/clear
obstruction, or replace
cabinet fan.

Replace capacitor.
Check electrical c

for compressor.

Problem

Probable Cause

Solution

Compressor runs with
intermittent high pressure
alarm and low oxygen
concentration.

Defective sieve beds.
Restriction in exhaust

muffler.

Replace sieve beds.
Replace or clean muffler.

Defective gearmotor / valve.
Compressor relief valve
releases (popping sound).

Constant alarm with I/0
(ON/OFF) switch in ON
position. Circuit breaker
repeatedly trips.

Alarm does not sound. Dead battery.

Defective gearmotor.

Defective control valve.

Contaminated sieve beds.

Defective relief valve.

Defective circuit breaker.

Defective capacitor.

Defective compressor.

Defective circuit board.

Faulty electrical connection.

Incorrectly installed battery.

Replace sieve module.
Replace sieve module.

Replace sieve module.
Replace sieve module.
Replace relief valve.
Replace circuit breaker.
Replace capacitor.
Replace compressor.
Replace circuit board.
Repair electrical connection.

Replace battery.
Reinstall battery with correct

polarity.
Faulty electrical connection.
Defective I/0 (ON/OFF)

switch.
Defective buzzer.
Defective pressure sensor.

Flow meter fluctuates. Improperly set or faulty

product regulator.
Leak.
Worn compressor.
Defective flow meter.
Kinked tubing

Repair electrical connection.

Replace I/0 (ON/OFF)

switch.

Replace board.

Replace and test control

board.

Check regulator

setting/clean, repair, or

replace regulator.

Leak test.

Replace compressor

Replace flow meter.

Check tubing that connects

the top of the sieve beds.

2010-2225 Rev - B Page 31 of 59

Problem

Probable Cause

Solution

Cabinet fan does not turn. Defective cabinet fan.

Replace cabinet fan.
Defective electrical

connections.

Limited or Iow flow. Restriction in humidifier or

tubing.
Product regulator set too

low.
Leak.
Weak compressor.

Air flow obstruction.

Low concentration. Compressor inlet air filter is

dirty or partially blocked.
System leak

Check electrical connections.

Replace humidifier or tubing.

Adjust regulator setting.

Leak test and repair leak.

Check system pressure, and

rebuild or exchange

compressor.

Check filter, suction

resonator, and suction tube

for obstruction.

Replace inlet air filter.

Leak test and repair leak.
Faulty compressor

Unit temperature too high,

Contaminated sieve beds.

Defective rotary valve.

Restriction in exhaust
muffler,

Restriction in suction
resonator.

Check system pressure, and

rebuild or replace

compressor.

Blocked air intake or

defective cabinet filter.

Check that P1 and P2

pressures are within range.

Replace sieve module.

Repair or replace sieve

module.

Replace or clean exhaust

muffler.

Check suction resonator and

suction tube for obstruction

and remove.

Page 32 of 59 2010-2225 Rev - B

6.5 Tool Kit and Pressure Test Gauge

The tools needed for you to properly service the Mark5 Nuvo® unit are listed below:

► Requires no special tools; generally available tools including common pliers, channel lock,

wire cutters, needle-nose pliers, slotted-head screwdriver, long Phillips head screwdriver, 8­inch adjustable wrench, 7/16-inch socket, 7/16-inch combination wrench, 5/8-inch
combination wrench and 3/8-inch combination wrench.

► For convenience, it is desirable to have a battery operated drill motor available to remove

and install screws.

► An accurate pressure test gauge to take both high and low pressure readings on the Mark5

Nuvo® unit should be kept available at all times. This gauge connects to the pressure test
ports on top of the air tank and on top of the sieve bed.

Appendices

Exploded Drawings

Base Assembly A-1, A-1.1
Main Structure Assembly A-2, A-3
Pressure Regulator Assembly A-4
Compressor Assembly A-5, A-5.1
Control Panel Assembly A-6, A-6.1, A-7, A-7.1, A-8, A-9
Air Tank Assembly A-10, A-10.1
Front Cabinet Assembly A-11, A-11.1
Rear Cabinet Assembly A-12, A-12.1
Sieve Module A-13

Refer to Thomas Compressor Manual (FSM 0159 Rev A dtd 07/04 for compressor rebuild
procedures. Call Nidek Medical customer service to obtain a pdf file copy.

2010-2225 Rev - B Page 33 of 59

A-1 BASE ASSEMBLY

NUVO 0100-0300 REV A

NOTE: USE THIS DRAWING ON UNITS EARLIER THAN SERIAL # 062-11663

Page 34 of 59 2010-2225 Rev - B

A-1.1 BASE ASSEMBLY
Nuvo 0100-0300Q Rev B

NOTE: USE THIS DRAWING ON UNITS AFTER SERIAL # 062-11663

2010-2225 Rev - B Page 35 of 59

A-2 MAIN STRUCTURE ASSEMBLY

FRONT VIEW

NUVO 0140-0300 REV C

Page 36 of 59 2010-2225 Rev - B

A-3 MAIN STRUCTURE ASSEMBLY

REAR VIEW

NUVO 0140-0300 REV C

2010-2225 Rev - B Page 37 of 59

A-4 REGULATOR ASSEMBLY

NUVO 0160-0300 REV A

Page 38 of 59 2010-2225 Rev - B

A-5 COMPRESSOR ASSEMBLY

NOTE: USE THIS DRAWING ON UNITS EARLIER THAN SERIAL # 062-11663

Nuvo 0200-0300 Rev. A

2010-2225 Rev - B Page 39 of 59

A-5.1 COMPRESSOR ASSEMBLY

NOTE: USE THIS DRAWING ON UNITS AFTER SERIAL # 062-11663

Nuvo 0200-0350 Rev. B

Page 40 of 59 2010-2225 Rev - B

A-6 CONTROL PANEL ASSEMBLY

UNIT WITH OCSI

FRONT VIEW

NOTE: USE THIS DRAWING ON UNITS EARLIER THAN SERIAL # 062-11663

Nuvo 0300-0330 Rev. A

2010-2225 Rev - B Page 41 of 59

A-6.1 CONTROL PANEL ASSEMBLY

UNIT WITHOUT OCSI

FRONT VIEW

NOTE: USE THIS DRAWING ON UNITS AFTER SERIAL # 062-11663

Nuvo 0300-0300 Rev. B

Page 42 of 59 2010-2225 Rev - B

A-7 CONTROL PANEL ASSEMBLY

UNIT WITH OCSI

REAR VIEW

NOTE: USE THIS DRAWING ON UNITS EARLIER THAN SERIAL # 062-11663

Nuvo 0300-0330 Rev. A

2010-2225 Rev - B Page 43 of 59

A-7.1 CONTROL PANEL ASSEMBLY

UNIT WITH OCSI

REAR VIEW

NOTE: USE THIS DRAWING ON UNITS AFTER SERIAL # 062-11663

NUVO 0300-0330 REV.B

Page 44 of 59 2010-2225 Rev - B

A-8 CONTROL PANEL ASSEMBLY

STANDARD UNIT WITHOUT OCSI

FRONT VIEW

NUVO 0300-0300 Rev A

2010-2225 Rev - B Page 45 of 59

A-9 CONTROL PANEL ASSEMBLY

STANDARD UNIT WITHOUT OCSI

REAR VIEW

NUVO 0300-0300 Rev A

Page 46 of 59 2010-2225 Rev - B

A-10 AIR TANK ASSEMBLY

NOTE: USE THIS DRAWING ON UNITS EARLIER THAN SERIAL # 062-11663

NUVO 0350-0300 REV. B

2010-2225 Rev - B Page 47 of 59

A-10.1 AIR TANK ASSEMBLY

NOTE: USE THIS DRAWING ON UNITS AFTER SERIAL # 062-11663

NUVO 0350-0300 REV. B

Page 48 of 59 2010-2225 Rev - B

A-11 FRONT CABINET ASSEMBLY

Nuvo 0500-0300 Rev. A

2010-2225 Rev - B Page 49 of 59

A-11.1 FRONT CABINET ASSEMBLY

Nuvo 0500-0300 Rev. B

Page 50 of 59 2010-2225 Rev - B

A-12 REAR CABINET ASSEMBLY

NUVO 0550-0300 REV A

2010-2225 Rev - B Page 51 of 59

A-12.1 REAR CABINET ASSEMBLY

Nuvo 0550-0300 Rev. B

Page 52 of 59 2010-2225 Rev - B

A-13 SIEVE MODULE ASSEMBLY

NUVO 0600-0300 Rev A

2010-2225 Rev - B Page 53 of 59

REPLACEMENT PARTS LISTING

BASE ASSEMBLY

MAIN STRUCTURE ASSEMBLY

REGULATOR ASSEMBLY

Item numbers reference call-out bubbles on the illustrations

Item Part Number Description Qty UOM

1 9250-1000 BASE, NUVO 1 EA
2 8300-8068 CASTER 4 EA
3 9250-1066 FOAM,BASE ASSY. 1 EA

1 9250-1003 BASE, PLATE NUVO 1 EA
2 9250-1004 STRUCTURE,MAIN NUVO 1 EA
3 7206-0027 BATTERY, 9 VOLT 1 EA
4 9250-1017 HOURMETER,UNV SNAP-IN 1 EA
5 9250-1047 BOLT, 1/4 -20 X 3/4" LG.GRADE2 4 EA
6 9250-1020 WASHER,FLAT 1/4" 5 EA
7 9250-1028 FILTER, AIR INLET 1 EA
8 6814-9228 ELBOW, 1/2 DOUBLE BARB, NYLON 2 EA

9 9250-1030 GOMMET,RUBBER 3 EA
10 9250-1069A TUBE,ASSY.SOUND INLET 1 EA
11 9250-1500 HARNESS,WIRING 115 VOLT 1 EA

11a 9250-1510 HARNESS, WIRING 230 VOLT 1 EA

12 9250-1059 CONNECTOR,MOLDED INLET 1 EA
13 9250-1022 CAPACITOR,15UF W/STUD MOUNT 1 EA
14 9250-1027 HOSE,PREFORMED CLEAR 1 EA
15 9250-1051 FOAM, EXHAUST MUFFLER 2 EA
16 7854-6065 HOSE 1/2"IDX .728"OD X 14.5" L 1 EA
17 9250-1046 SCREW 10 X..5"LG HEX WASHER 1 EA
18 9250-1062 TIE WRAP, 14" LONG 2 EA
19 9250-1102 FOAM,KIT VIBRATION 1 EA
25 9030-6008 TIE, WRAP 4~ 5 EA
26 9250-1058 BOLT, 1/4 -20 X .5" LG. 1 EA

1 9250-1043 HOSE, 1/4 OD X 7" LG 1 EA

2 6814-9221 ELBOW , 1/8 NPTF X 1/4 ODT 1 EA

3 9250-1060 REGULATOR,2 PORT FREEDOM 1 EA

4 7854-6054 HOSE 5/32 X 11/32 X 10"LG SIL 1 EA

5 6491-1008 TEE NYLON 3/16 HOSE BARB 1 EA

6 7854-6052 HOSE 5/32 X 11/32 X 2 LG SILIC 1 EA

7 6956-9674 VALVE CHECK ¼ HOSE MPC A 975 1 EA

Page 54 of 59 2010-2225 Rev - B

COMPRESSOR ASSEMBLY

1 9250-1018 PLATE, COMPRESSOR 1 EA

CONTROL PANEL ASSEMBLY (OCSI MODEL)

2 9250-1023 FAN, MUFFIN 110 VOLT 1 EA
2a 9250-1024 FAN, MUFFIN 230 VOLT 1 EA

3 7355-3638 COMPRESSOR 2660 110V 1 EA
3a 7355-3639 COMPRESSOR 2660 230V 1 EA

4 9250-1052 FITTING,BRASS 1/4"NPX3/8" TUBE 1 EA

5 9250-1094 TUBE,HEAT EXCH. 3/8" O.D. 1 EA

6 6191-5003 ELBOW, NYL 1/4 NPT X 1/2 HOSE 1 EA

7 9250-1016 SPRING,COMPRESSOR VIBRATION 4 EA

8 9250-1105 BOLT,1/4"X20X2"LGGRADE 2 4 EA

9 9250-1111 SLEEVE,1/4"ID X 1.29"LG 4 EA
10 9250-1112 CAP,COMP. SPR. TOP 4 EA
12 9250-1109 WASHER,FLAT .25"ID X 1.25"OD 4 EA
13 9250-1110 WASHER,LOCK 1/4" ID. 4 EA
14 9250-1049 BRACKET, EXH.TUBE COMP. 1 EA
15 9250-1058 BOLT, 1/4 -20 X .5" LG.GRADE2 3 EA
16 9250-1020 WASHER,FLAT 1/4" 3 EA
17 9250-1029 CLAMP, HOSE NYLON.538"-.608"ID 2 EA
18 9250-1115 HOSE 3/8 ID X .375"X.575"X5.0" 1 EA
19 9250-1064 BUMPER, .5'DIAX .06 THK. BLACK 4 EA
99 9030-6008 TIE, WRAP 4~ 1 EA

1 9250-1005 PANEL,CONTROL 1 EA

2 9250-1080 BOARD, OCSI MODULE 1 EA

3 9250-1045 SCREW,PLASTITE#4X3/8" PAN.HD 2 EA

4 9250-1041 HOSE 5/32 X 11/32 X 5 LONG SIL 1 EA

5 7631-1053 FILTER, BACTERIAL MK-5 1 EA

6 7854-6051 HOSE 5/32 X 11/32 X 3 LONG SIL 1 EA

7 6956-9674 VALVE CHECK 1/4 HOSE MPC A 975 1 EA

8 9250-1012 SWITCH,POWER 110 VOLT 1 EA
8a 9250-1013 SWITCH,POWER 230 VOLT 1 EA

5 6491-1007 ADAPTER 5/32 X 3/32 HOSE BARB 1 EA

6 7854-6050 HOSE 5/32 X 11/32 X 6 LONG SIL 1 EA

7 6491-1006 ADAPTER 1/4 ODT X 3/16 HOSE 1 EA

9 9250-1050 SCREW, 10-32 X 3/8 PAN HD.PHIL 8 EA
10 9250-1040 O-RING, 5.0" ID X .125THICK 2 EA
11 9250-1048 WASHER,NYLON .44"IDX.75"X.062" 1 EA
12 9007-6G32 HUMIDIFIER FITTING DISS 1 EA
13 9250-1039 COVER,PRESS TO RESET 3/8" 1 EA
15 9250-1009 FLOWMETER, 0-5 LPM 1 EA
16 9250-1011 BREAKER,CIRCUIT 10 AMP 1 EA

16a 9250-1010 BREAKER, CIRCUIT 5 AMP 1 EA

2010-2225 Rev - B Page 55 of 59

18 9250-1038 NUT,HEX ,NICKEL 3/8"-27 1 EA

CONTROL PANEL ASSEMBLY (STD

–

NON OCSI)

AIR TANK ASSY,NUVO

19 9250-1021 HUMIDIFIER BLOCK 1 EA
20 7854-6052 HOSE 5/32 X 11/32 X 2 LG SILIC 1 EA
21 7854-6054 HOSE 5/32 X 11/32 X 10"LG SIL 1 EA
22 7854-6055 HOSE 5/32 X 11/32 X 7"LG SIL 1 EA

1 9250-1005 PANEL,CONTROL 1 EA

2 9250-1090 BOARD, STD NON-OCSI 1 EA

3 9250-1045 SCREW,PLASTITE#4X3/8" PAN.HD 2 EA

4 7854-6048 HOSE 1/16 X 3/16 X 5 LONG SILI 1 EA

5 6491-1007 ADAPTER 5/32 X 3/32 HOSE BARB 1 EA

6 7854-6050 HOSE 5/32 X 11/32 X 6 LONG SIL 1 EA

7 6491-1006 ADAPTER 1/4 ODT X 3/16 HOSE 1 EA

8 9250-1041 HOSE 5/32 X 11/32 X 5 LONG SIL 1 EA

9 7631-1053 FILTER, BACTERIAL MK-5 1 EA
10 7854-6052 HOSE 5/32 X 11/32 X 2 LG SILIC 1 EA
11 6956-9674 VALVE CHECK 1/4 HOSE MPC A 975 1 EA
12 9250-1012 SWITCH,POWER 110 VOLT 1 EA

12a 9250-1013 SWITCH,POWER 230 VOLT 1 EA

13 9250-1050 SCREW, 10-32 X 3/8 PAN HD.PHIL 8 EA
14 9250-1040 O-RING, 5.0" ID X .125THICK 2 EA
15 9250-1048 WASHER,NYLON .44"IDX.75"X.062" 1 EA
16 9007-6G32 HUMIDIFIER FITTING DISS 1 EA
17 9250-1039 COVER,PRESS TO RESET 3/8" 1 EA
19 9250-1009 FLOWMETER, 0-5 LPM 1 EA
20 9250-1011 BREAKER,CIRCUIT 10 AMP 1 EA

20a 9250-1010 BREAKER, CIRCUIT 5 AMP 1 EA

22 9250-1038 NUT,HEX ,NICKEL 3/8"-27 1 EA
23 9250-1021 HUMIDIFIER BLOCK 1 EA
24 7854-6054 HOSE 5/32 X 11/32 X 10"LG SIL 1 EA
25 7854-6055 HOSE 5/32 X 11/32 X 7"LG SIL 1 EA
99 9030-6008 TIE, WRAP 4~ 1 EA

1 9250-1031 TUBE,AIR TANK ALUM 3/8" 1 EA

2 9250-1019 BRACKET,AIR TANK 1 EA

3 6134-0916 SCREW,10-32 X 1/2~ RD PHILLIPS 1 EA

4 9250-1037 NUT,10-32 ,LOCKNYLON INSERT 1 EA

5 9250-1056 FITTING,BRASS AIR TANK 1 EA

6 7355-4775 CONNECTOR, STRAIGHT 1/8~MNPT X 2 EA

7 9250-1055 TANK, AIR 6"O.D. X 10" LG 1 EA

8 9007-4G25 WICK ASSY. 1 EA

9 9250-1026 CLAMP, HOSE NYLON.67"-.78"ID 2 EA

Page 56 of 59 2010-2225 Rev - B

10 9250-1053 HOSE 1/2"ID X 3/4"OD X 10.125" 1 EA

POWER CORD ASSEMBLY

CABINET FRONTASSEMBLY

CABINET BACK ASSEMBLY

MODULE ASSEMBLY

LABELS

SHIPPING MATERIAL

11 9200-1006 FITTING, QUICK DISCONNECT 1 EA
12 9200-1612 HOSE, 1/4 OD X 18 LG 1 EA

1 9250-1311 CORD,POWER CONC (US) 1 EA
1A 9250-1330

1 9250-1002 CABINET,FRONT NUVO 1 EA

2 9250-1050 SCREW, 10-32 X 3/8 PAN HD.PHIL 4 EA

1 9250-1001 CABINET,BACK NUVO 1 EA

2 9250-1006 DOOR,ACCESS NUVO 1 EA

3 9250-1025 FILTER,CABINET INLET 1 EA

4 9250-1050 SCREW, 10-32 X 3/8 PAN HD.PHIL 4 EA

CORD,POWER CONC (Europe)

1 9250-8005

2 9022-8G06
1A 9250-8008
2A 9022-8G07 MODULE 230 V 50 HZ , REBUILT 1 EA

1 9250-1076 LABEL,FRONT STD. 1 EA
1A 9250-1078 LABEL, FRONT W/OCSI 1 EA

2 9250-1070 LABEL FRONT "NUVO" 1 EA

3 9250-1071 LABEL,TOP WARNING ICON 1 EA

4 9250-1075 LABEL BACK 115/60 1 EA
4A 9250-1077 LABEL BACK CE 1 EA

7 2010-2224F OPERATING GUIDE, STD NUVO 1 EA
7A 2010-2224CE OPERATING GUIDE, CE MODEL 1 EA

1 9250-1600 CARTON, CONCENTRATOR NUVO 1 EA

2 9250-1601 PACK, BOX TOP 1 EA

3 9250-1602 PACK, BOX BOTTOM 1 EA

MODULE 115 V 60 HZ NEW
MODULE 125 V 60 HZ REBUILT
MODULE 230 V 50 HZ NEW

1 EA
1 EA
1 EA

1 9012-8780 CANNULA W/7 FT TUBING 1 EA

2 9012-8781 TUBING EXTENSION 25 FT 1 EA

3 9012-8774 HUMIDIFIER 350 CC 1 EA

4 9012-8783 HOSE CONNECTOR 1 EA

5 9012-8785 ADAPTER DISS TO HOSE 1 EA

2010-2225 Rev - B Page 57 of 59

ACCESSORIES

Nidek Medical Oxygen Concentrator Service and Maintenance Log

Model Number ________________

Initial Inspection

1. Upon receipt, check the unit for shipping
damage. Notify shipping company if damaged.

2. Verify that cabinet air filter and the inlet air filter
are in place.

3. Plug the unit into an electrical outlet, turn the unit
'ON,’ and check the audible/visual alarms.

4. Set the flow meter/flow control at the maximum
recommended flow rate and allow the unit to run for
15 minutes.

5. Using a calibrated oxygen analyzer, verify
concentration is greater than 87 percent.

Routine Service Check

Perform routine servicing as shown in the chart
below. Record the activities performed in the log
provided on the following page.

1. Record the elapsed usage time in hours.

2. Check oxygen concentration with a calibrated
oxygen analyzer.

3. Verify audible alarm and indicator light functions
between patients and every two years.

4. Inspect filters and replace as necessary.

Serial Number ___________________

Between-Patient Maintenance

1. Remove oxygen tubing, cannula, and humidifier
bottle and discard.

2. Wash or replace the humidifier tubing if used.

3. Wash or replace the cabinet air filter.

4. Clean the concentrator cabinet.

5. Check oxygen concentration and flow. If the unit
performs within specification, the final product
filter does not need to be replaced between patients.

Patient/Caregiver Maintenance

1. Inspect the Oxygen tubing, cannula, and
humidifier bottle - clean as needed according to
manufacturer’s instructions.

2. Wash the cabinet air filter weekly with a mild
detergent solution. Dry before reinstalling onto the
device.
The routine service intervals shown below depend
on the conditions in which the devices are used.
They reflect the minimum recommendation when
operated in a clean environment. As conditions can
vary widely, the homecare provider or patient
caregiver is responsible to determine:

- the character of the environment in which the
concentrator is to operate.

- a maintenance schedule with intervals based on
the environment in which the unit is
operating/functioning.

Standard Servicing Intervals are shown below. Intervals used by the homecare service provider
and/or patient caregiver should be more frequent when conditions of usage dictate.

Nidek Medical Oxygen Concentrator Routine Service Intervals

Check Percent

Oxygen

Concentration

OCSI Models: Every

15,000 hours

or 3 years.

Std Models: Every

5,000 hours or 1

year.

Page 58 of 59 2010-2225 Rev - B

Cabinet Air Filter Inlet Air Filter Final Product Filter Capacitor

Wash the filter
each week in a

mild detergent

solution.

Dry before

reinstalling.

Inspect at each

patient visit. Replace

annually, or more

often depending on

environment.

Replace at each

compressor

service / module

replacement.

Replace at each

compressor

service / module

replacement.

Please maintain a log of all maintenance
activities performed on this unit.

Serial Number__________Model_____________

Date Hours % O2

Inspection Prior to Putting Into Service

In-Service Checks

Alarms

Check

Additional Information (Work Done, Filter Changes,

Comments, etc)

Medical device regulations require users and service personnel to notify manufacturers of any

incidents that, if repeated, could cause injury to any person.

email: [e-mail]

Please update maintenance log information upon each service at www.nidekmedical.com under

the 'Maintenance Log' tab.

2010-2225 Rev - B Page 59 of 59