OCENCO M-20 User manual

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Ocenco Incorporated
M-20
Self Contained Self Rescuer
Instruction Manual
Manual No. N22069
Revision A, ECN 3071

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Contents:
1. Introduction
2. Description of the M-20
2.1 Classification
2.2 Limitations
2.3 Components
2.4 Theory of Operation
2.5 Specifications
3. M-20 Care and Maintenance
3.1 How to Care for the M-20
3.2 How to Inspect the M-20
4. Donning Instructions
4.1 When to use the M-20
4.2 How to use the M-20
4.3 Transition from the M-20 to the EBA 6.5.

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1. Introduction
The M-20 was designed with two primary objectives, reliability and ease of use. The
M-20 is the easiest of all self-rescuers to use. Six simple steps (see section 5.4) and
these six steps should be practiced over and over by the trainees until it becomes
second nature.
Inquiries regarding Ocenco Breathing Devices should be directed to:
Ocenco Incorporated
LakeView Corporate Park
10225-82nd Avenue
Pleasant Prairie, WI 53158
U.S.A.
Telephone: [phone]
Facsimile: [phone]
E-mail: sal[email protected]

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2. Description of the M-20
2.1 Classification
The Ocenco M-20 is a compressed oxygen, self-contained escape breathing
apparatus. Self-contained means the M-20 supplies breathable air independent of the
surrounding atmosphere. The M-20 will provide breathable air to a person escaping
from an area of toxic gas or oxygen deficiency.
2.2 Limitations
2.2.1 Escape Breathing Apparatus
All self-rescuers, including the M-20, are considered escape breathing
apparatus. Escape breathing apparatus should not be used to actively fight
fires or intentionally enter toxic atmosphere unless it is necessary to pass
through a toxic atmosphere to escape.
2.2.2 Physical Exertion
All breathing apparatus, including self-rescuers, place some limited amount
of stress on the user due to either the weight of the unit, increased
breathing resistance or an increase in temperature of the inhaled air. For
this reason it is always advisable to limit the level of physical exertion, if
possible, while wearing any self rescuer.
2.2.3 Duration
The M-20 is approved jointly in the United States by the National Institute of
Occupational Safety and Health (NIOSH) and the Mine Safety and Health
Administration (MSHA) for a duration of 10 minutes. The duration of all self-
rescuers can vary depending on the user’s oxygen consumption rate. Five
factors affect the user’s oxygen consumption rate:
1.) The amount of work required to escape affects the duration.
Low ceilings, steep inclines and irregular floors increase the
work required to escape. Less work results in greater duration.
2.) The Physical condition or “fitness”of the user affects the
duration. A high heart rate, old age, and high percent of body
fat decrease the fitness of the subject. The more fit the user,
the greater the duration.
3.) Regardless of the “fitness”of the user, the amount of oxygen
required in proportional to the user’s weight. The less the user
weighs, the greater the duration.
4.) The user’s breathing rate affects the duration. The rate can be
increased by excitement and fear. The lower the breathing rate,
the greater the duration.
5.) The degree of training and familiarity can affect the duration.
The more training and experience the subject has with self-
rescuers, the more his breathing will be calm and controlled. If a
subject is familiar with a particular escape way it may improve
the mechanics of his escape. The greater the training and
familiarity, the greater the duration.

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2.3 Components
The M-20 consists of four main assemblies: the cover, the base, the latch and the
breathing Assembly. In the description of these assemblies the component names
are in UPPERCASE letters.
2.3.1 COVER Assembly
The COVER has an integral yellow TAB which, when lifted, releases any
vacuum developed due to the change in atmospheric pressure from the
surface to underground. Two cover overcases are affixed to the cover to
provide protection from shock and vibration.
2.3.2 BASE Assembly
The clear BASE has integral belt loops and a base overcase that is affixed
to the bottom of the base to provide protection from shock and vibration.
2.3.3 LATCH Assembly
The stainless steel LATCH band and stainless steel S-HOOK attach to
opposite sides of the BASE and clamp the COVER to the BASE. The S-
HOOK attaches to the user side of the BASE.
The LATCH band is released by raising the yellow lever on the LATCH
band. After the lever is raised, the COVER can be separated from the
BASE. The BASE stays attached to the user’s belt, and the COVER is
discarded. The yellow nylon NECK STRAP is exposed after the COVER is
removed.
The yellow lever holds a tamper ball that falls away when the lever is lifted.

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M-20 Case
1. Cover
2. Overcase Cover
3. Latch Band
4. Base
5. Overcase Base
6. S-Hook
7. Tamper Ball
8. Lever
5
4
231
1
7
3
2
5
4
8
6

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2.3.4 BREATHING ASSEMBLY
1. Noseclip: the Noseclip is attached to the Mouthpiece. The yellow pads
on the Noseclip are made of high quality natural rubber to grip the nose.
2. Mouthpiece: the yellow Mouthpiece is molded of high strength silicone
rubber. The Mouthpiece is placed in the mouth where the flange on the
Mouthpiece seals in front of the gums and the stops on the Mouthpiece
keep the mouth slightly open.
3. Neck Strap: pulling upwards on the yellow Neck Strap, disconnects the
Activation Cable from the Oxygen Controller. This action starts the flow
of oxygen into the Breathing Bag.
4. Neck Strap Ring: pulling upward on the Neck Strap Ring, shortens the
Neck Strap. It is particularly helpful to shorten the Neck Strap in
crawling situations.
5. Cylinder: the stainless steel Cylinder is of single piece construction with
no welds or joints of any kind. All of the oxygen supplied to the user is
USP grade compressed oxygen.
6. Oxygen Controller: the Oxygen Controller starts the flow of oxygen into
the Breathing Bag and automatically increases the oxygen flow during
high work rates.
7. Gauge: the Gauge indicates the amount of oxygen in the Cylinder. The
green zone on the Gauge indicates the Cylinder is full of oxygen. The
red zone indicates the Cylinder is low on oxygen and should be
removed from service.
8. Activation Cable: the stainless steel Activation Cable is attached to the
oxygen Controller and permanently attached to the inside of the Base.
Pulling the M-20 out of its Base releases the Activation Cable from the
Oxygen Controller and starts the flow of oxygen into the Breathing Bag.
9. Scrubber: the Scrubber is a chamber of Lithium Hydroxide that “scrubs”
or removes the carbon dioxide from the exhaled air.
10. Breathing Bag: the orange Breathing Bag is a 6.5 liter reservoir that
receives oxygen from the Oxygen Controller and exhaled air from the
Scrubber.
11. Relief Valve: the Relief Valve is a one-way valve that allows any
excess air in the Breathing Bag to escape. The Relief Valve limits the
pressure on the lungs during exhalation. The Relief Valve is located in
the middle of the Breathing Bag.
12. Information Label: contains unit serial number, manufacturing date,
carry date, and store date.

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M-20 Breathing Assembly
3
4
11
10
1
2
5
9
12
6
7
8
1. Noseclip (yellow)
2. Mouthpiece (yellow)
3. Neck Strap (yellow)
4. Neck Strap O-ring
5. Cylinder
6. Oxygen Controller
7. Gauge
8. Activation Cable
9. Scrubber
10. Breathing Bag
11. Relief Valve
12. Information Label

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2.4 Theory of Operation
1.) When the Neck Strap is pulled from the Base, the oxygen valve is activated.
Oxygen continuously flows from the cylinder to the Breathing Bag at a rate if
1.5 liters per minute.
2.) During the first inhalation, and when the Bag flattens, the Demand Regulator is
activated and increases the oxygen flow from 1.5 liters per minute up to as
much as 100 liters per minute.
3.) During inhalation, oxygen is pulled from the bag through the Scrubber and into
the Mouthpiece.
4.) During exhalation, carbon dioxide laden air is exhaled into the Mouthpiece
through the Scrubber and into the Breathing Bag. During inhalation and
exhalation, the carbon dioxide is being absorbed by the Lithium Hydroxide
scrubber.
5.) Sometimes during low work rates, the oxygen controller will supply more
oxygen than the user can consume and excess gas exits the Relief Valve.
The starting of the oxygen flow, the increased flow rate during high work rates
and the occasional exhausting of gas through the Relief Valve all occur
automatically, the user needs only to breathe.
2.5 Specifications
Duration: 10 minutes, NIOSH / MSHA
Dimensions: 3.0 x 6.5 x 7.2 (in)
7.6 x 16.5 x 18.3 (cm)
Weight of breathing apparatus: 2.0 lbs (0.9 kg)
Weight of breathing apparatus with case: 3.30 lbs (1.5 kg)
Minimum storage temperature: 10 degrees F (-12º C)
Maximum storage temperature: 140 degrees F (60º C)
Storage at temperatures above 140 degrees F (60º C) for short periods will not
adversely affect the M-20. In an emergency, don the M-20 regardless of
temperature.
Scrubber life is limited to one escape event or one oxygen charge
Mandatory factory service is required after 10 years if stored and 5 years if
M-20 is carried. End of service life is 15 years.

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M-20 Theory of Operation
3
2
4
5
1
1. Constant Flow of Oxygen
2. Demand Flow of Oxygen
3. Inhalation
4. Exhalation
5. Relief Valve Exhaust

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3. M-20 Care and Maintenance:
3.1 How to Care for the M-20
The M-20 is designed to be belt worn in an underground mining environment.
The M-20 is fully shock absorbed in all directions within an impact and abrasion
resistant case. Ocenco, Incorporated, NIOSH (USA), and private testing
laboratories have performed numerous durability tests on the M-20 to ensure that
it will withstand the harsh underground mining environment. However, like all self-
rescuers it is not indestructible. Abusing your own self-rescuer is risking your life
in the event of an emergency. Abusing someone else’s self-rescuer should be
considered criminal. Within the system of distributing the M-20’s to mining
personnel there should be consideration for accountability of the condition of the
self-rescuer when it is returned. Teaching trainees to care for the M-20 must be a
combination of instruction and enforcement.
Your life may depend on the care you give your self-rescuer. The list of things
you should NOT do to the M-20 could be extensive. The more common abuses
are:
1.) If the M-20 is accidentally opened, do not attempt to re-close it.
2.) Do not drop the M-20, particularly when taking off the belt.
3.) Do not clean the M-20 with anything other than soft brush.
4.) Do not immerse the M-20 in water. Even though the M-20 has been
tested to withstand immersion in water, it is not recommended on a
regular basis.
5.) Do not sit on the M-20.
6.) Do not drag the M-20 on the ground.
7.) Do not place the M-20 near heat greater than 140º F (60º C).
8.) Do not put tape or stickers on the M-20 that would impede its opening
or reading the gauge.

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3.2 How to Inspect the M-20
The M-20 must be visually inspected on a daily basis prior to being used
underground.
Your inspection should consist of the following:
1.) Check the gauge. The pointed white indicator on the Gauge is normally
in the green. Remove the M-20 from service if the white Gauge
Indicator is in the red. If the case is damaged and the gauge cannot be
read, the unit must be removed from service. If the view through the
clear Base is obstructed for any reason, such that a proper examination
cannot be performed (e.g. scuff marks, stickers, paint) the M-20 must
be removed from service. The white mark on the Gauge is the zero
pressure mark.
2.) Inspect the apparatus for the indications of high force impacts.
Indications of high force impacts are listed below. If any of these signs
are present the M-20 must be removed from service:
a. Case cracked, burned, deformed, or excessively worn.
b. Excessive gap between Cover and Base. This indicates that unit
has been opened and re-closed.
c. Damaged Latch or Cover Band. Severe dents or wear spots in
the band or the band is out of position.
d. Gauge bent or white indicator needle broken.
e. Dirt, debris, or moisture visible through the Case.
f. Belt loops broken. A cracked Belt Loop is an indication of a
severe impact while off the belt.
3.) Missing Tamper Ball
4.) Ensure that the M-20 EEBD has not exceeded the life date printed on
the information label.
Ensure belt worn period (5 consecutive years) has not expired.
If the M-20 fails any of the above inspections, it should be removed from service
and returned to Ocenco Incorporated facility.

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4. Donning Instructions:
4.1 When to use the M-20
The M-20 should be used immediately at the first indication of a fire or explosion
even though no smoke is visible. Carbon monoxide is odorless and colorless, so
you could breathe fatal amount of the gas before smoke is present. If you
suspect an oxygen deficient atmosphere, put on the M-20 since it also gives you
protection in an oxygen depleted atmosphere. Don’t wait: put on the apparatus
and escape to fresh air.
Possible Indications of an emergency:
1. Sight of smoke
2. Smell of smoke
3. Sight of fire
4. Fire alarm or carbon monoxide alarm
5. Sudden increase of air temperature
6. Sound of explosion
7. Vibrations of explosion
8. Interruption of ventilation
9. Someone around you has difficulty breathing or passes out
In the event of an emergency, always don your self-rescuer before attempting to
escape or help others.
4.2 How to Use the M-20
4.2.1 Donning the M-20:
1.) Release yellow lever and discard cover.
2.) Remove unit by pulling yellow neck strap upwards.
3.) Insert yellow mouthpiece.
4.) Fit yellow noseclip
5.) Fit and adjust yellow neck strap
6.) Breathe through mouth and escape.
These are the six fundamental steps that should be practiced numerous times by
the trainees.
Depending on style of hardhat used, it may be necessary to remove the hat before
fitting the neck strap.

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4.3 Transition from the M-20 to EBA 6.5
It is critical that the overall escape strategy is complete and accounts for
mining personnel reaching the surface. If the escape time is greater than
the duration of the self-rescuer, provision must be made to further protect
the mining personnel. Storing the Ocenco, Incorporated EBA 6.5 within
reach of the M-20 allows an extension of escape time.
Transition from the M-20 to EBA 6.5 should first be illustrated by use of the
training video and then practiced, “hands on”, by the trainees. The training
video shows the donning of the M-20 and then shows the following
transition to the EBA 6.5:
Transition Instructions
1. Pull latch release pin.
2. Lift and pull each latch ring to release bands.
3. Remove cover from base. Grab the two handle straps and pull case apart,
discard cover and rubber seal.
4. Open oxygen valve fully counterclockwise, in direction of arrow.
5. Remove M-20 neck strap.
6. Place EBA 6.5 neck strap overhead.
7. Inhale from M-20, hold breath and remove the M-20 mouthpiece and
noseclip.
8. Pull EBA 6.5 mouthpiece toward face. The mouthpiece plug will
automatically be removed from the mouthpiece. Insert mouthpiece and
breathe through mouth only. Use head strap for additional support of
mouthpiece, if required.
9. Apply noseclip to nose. Do not attempt to inhale or exhale through your
nose.
10. Purge bag with oxygen to eliminate nitrogen: exhale, hold breath and deflate
bag by pressing on the bag. Inhale deeply through the mouthpiece, and
then breathe normally (oxygen will be supplied from the demand regulator).
11. Adjust neck strap for comfort.
12. Wrap waist harness around waist, clip and adjust for fit by pulling on strap
end.
13. Place goggles over eyes to prevent irritation from smoke or other irritants.
14. ESCAPE

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Proper handling, maintenance, and other information as supplied in this manual are
essential to the effective use of the EBA 6.5. The user should be familiar with Instructions
for Use 1-12 before attempting to use the EBA 6.5.
M-20 Approval Label