Contrinex SAFETINEX User manual

SAFETINEX
SAFETY LIGHT CURTAINS
HAND PROTECTION, TYPE 2
INSTRUCTION MANUAL

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Contrinex Industrial Electronics
ORIGINAL INSTRUCTIONS
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ding English:
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darunter Deutsch, zum Download bereit:
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línguas, incluindo o português:
http://www.contrinex.com/download/#anchor_manuals

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INTRODUCTION ...............................................................5
Contrinex ..............................................................................................5
Safetinex safety systems......................................................................5
Active optoelectronic protective devices (AOPD) ...............................5
Safeguarding function...................................................................6
Hazardous area.............................................................................6
AOPD detection capability............................................................6
Advantages of AOPDs .........................................................................7
Operating principle ..............................................................................7
Certification of Safetinex products.......................................................8
EUROPEAN SAFETY STANDARDS............................8
Types of safety standards applicable in the EU ..................................8
Examples of safety standards..............................................................9
An approach to European standards...................................................9
The user side......................................................................................10
Machine manufacturer side ...............................................................11
Notified bodies ...................................................................................11
NORTH AMERICAN SAFETY STANDARDS .........12
A different approach ..........................................................................12
OSHA Regulations and U.S. Consensus Standards..........................12
North American Standards for safety issues: UL, ANSI and CSA .....13
American standard agencies......................................................13
Canadian standard agencies .....................................................14
International standard agencies ........................................................14
RISK ASSESSMENT .......................................................15
Definition of hazards and risk reduction strategy ..............................15
Risk assessment process ..................................................................15
Methods for determination of risk level ..............................................18
Determination of risk level in North America...............................18
Determination of required performance level (PLr).....................18
Specific standards for safety distance calculation.....................20
INSTALLATION ...............................................................20
Installation rules .................................................................................20
Positioning the AOPD..................................................................20
Minimum safety distance required..............................................21
Minimum safety distance calculation (EU)..................................22
Minimum safety distance calculation (US & Canada) ................24
OTHER COUNTRIES .....................................................25
ACRONYMS .....................................................................26
TABLE OF CONTENTS

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TECHNICAL DOCUMENTATION.....................................27
Safetinex YBB for hand protection.....................................................27
Advantages of the Safetinex range....................................................27
Scope of this technical documentation..............................................28
Operating principle ............................................................................28
Self protected outputs........................................................................28
Resolution (R) of an AOPD.................................................................29
LED status indicators .........................................................................30
Configurable functions .......................................................................30
Test mode selection (YBB)..........................................................30
Installation ..........................................................................................31
Minimum safety distance ............................................................31
Positioning the sender and receiver units...................................32
Distance from reflective surfaces ...............................................33
Installation of multiple systems ...................................................34
Mechanical installation................................................................35
Connecting the protective device...............................................37
Power supply ........................................................................37
Electromagnetic compatibility (EMC) ...................................37
Light radiation.......................................................................37
Pin assignment .....................................................................38
Safetinex safety relay YRB-4EML-31S ...............................................39
Response time from prot. field intrusion to switching of safety relay 39
Connection examples for YRB-4EML-31S safety relay...............40
Alignment of sender and receiver unit...............................................41
Test before the first commissioning....................................................42
TESTING AND MAINTENANCE ...............................43
Daily functional test ............................................................................43
Hand protective devices (YBB models).....................................43
Troubleshooting..................................................................................44
Preventive periodic inspections.........................................................45
Cleaning .............................................................................................45
Daily testing log file ............................................................................45
AVAILABLE MODELS ...................................................47
Beam resolution: 30mm ....................................................................47
Technical data ...................................................................................48
DISCLAIMER ....................................................................48
EC DECLARATION OF CONFORMITY ...................50

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CONTRINEX
Contrinex, a multinational company with headquarters in Switzerland, is
specialized in the development, production and worldwide sales of po-
sition sensors, RFID and safety systems. Contrinex employs over 500
people, including 25 highly qualified R&D engineers, operates produc-
tion units in Switzerland, Hungary, China and Brazil, has its own sales
offices in all the major markets and is represented in over 60 countries.
Contrinex applies stringent management and production principles,
which are reflected in its ISO 14001:2004 and ISO 9001:2008 certifica-
tions. Additionally, Contrinex is subject to regular client-based audits.
Identical quality controls and equipment as well as staff recruitment and
training policies are implemented at the different production sites, thus
guaranteeing consistent product quality.
SAFETINEX SAFETY SYSTEMS
The Safetinex product lines produced by Contrinex offer high quality
safeguarding solutions for both personnel and machinery. Our special-
ists in sensor technology have developed high-performance electro-
sensitive protective equipment. Our range of safety products com-
prises highly sensitive devices for finger and hand protection as well
as access control, featuring various lengths and connection options.
Safetinex products have been developed in compliance with the ap-
plicable international safety standards and have obtained the required
product certification for use in the European Union, the United States
of America and all other countries where the applicable IEC standards
have been adopted.
ACTIVE OPTOELECTRONIC PROTECTIVE
DEVICES (AOPD)
When looking to build a safety system around a danger zone, the first
consideration is whether or not optical protection is suitable at all. For
this to be the case, it must be possible for the machine control to be
electrically influenced by means of the AOPD’s semiconductor output.
Moreover, it must also be possible to instantly terminate or exit the haz-
ardous process in every operating phase. Further, there must be no
danger of injury due to heat, radiation or from materials or components
ejected by the machine. If such danger exists, then either the optical
system is not suitable, or the danger must be otherwise excluded by
applying additional safety measures.
The selection of a specific type of safeguard involves an evaluation of
the hazard, in order to determine the applicable category or required
performance level PLr.
INTRODUCTION

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The choice of an active optoelectronic protective device (AOPD), such
as a safety light curtain, depends on:
–The relevant safety standards to be applied
–The definition of the safeguarding function
–The available space around the hazardous area
–The safety distance, as calculated by the appropriate formula and
depending on the AOPD’s resolution and position, as well as the re-
sponse times of the light curtain or access control barrier, the safety
relay and the machine stopping time
–Ergonomic factors (e.g. how often access is necessary)
–Commercial criteria
SAFEGUARDING FUNCTION
The AOPD resolution must be chosen according to the application and
the required safeguarding function. It is defined as the minimum size of
an object that can be reliably and safely detected at any position in the
protective field. Basically, two approaches can be considered:
–Point of operation: detection of hands entering the defined hazard-
ous area. The protective equipment immediately stops the machine
or renders it harmless. The Safetinex YBB range is best suited for
this type of application.
In both cases, the primary function of the protective device is to stop
the machine before the hazardous point is reached and to prevent un-
intentional machine start-up or restart. This function must comply with
the category or performance level of the safety-related components of
the machine’s control system.
HAZARDOUS AREA
The hazardous area can be defined in terms of:
–The dimensions of the zone that requires protection
–The different access points to accessible hazards
–The risk of an undetected presence in the hazardous zone, or risk of
bypassing the protective device
AOPD DETECTION CAPABILITY
The light curtain or barrier detection capability (or resolution) depends
on the distance between the centerlines of each beam emitted by the
sender. The choice for a specific resolution depends on the part of the
body which needs protection.

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ADVANTAGES OF AOPDS
Safeguarding devices are used where risks cannot be eliminated by
machine design. Rather than preventing access to a hazardous area,
safety light curtains or access control barriers detect the entry of a per-
son or part of a body and eliminate the hazard by triggering an im-
mediate stop of the hazardous machine motion. They present several
advantages over mechanical safeguarding devices:
–Access time to the machine is reduced, thereby increasing produc-
tivity
–Workplace ergonomics are greatly improved and less space is re-
quired
–The invisible infrared beams allow better visibility of the machine
and operating process
–Protection applies to any approaching person
OPERATING PRINCIPLE
A light curtain or access control barrier comprises two units, namely a
beam sender (or transmitter) and a receiver. The protective field is the
area enclosed by these two components, the emitted light beams form-
ing a permanent, though invisible, shield between the two units. The
FIG. 1: RESOLUTION OF THE LIGHT CURTAINS
Beam resolution 30 mm
FIG. 2: OPERATING PRINCIPLE
Emitter
Receiver
Protective field
Resolution (R)
Protective height
Operating distance (d)

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receiver unit is connected to a safety relay which transmits the signal to
the machine control unit. When properly installed, the protective device
detects any relevant entry into the hazardous area. As soon as such an
entry is detected, the protective device immediately triggers the safety
relay, which in turn causes the machine control system to bring the
machine to a safe status and/or complete stop, thus eliminating the
hazard.
The size of the protective field depends on the dimension of the AOPD
and the distance between the sender and receiver units.
AOPDs are also commonly used as sensors to automate industrial
operations where no critical human safety issue is involved. However,
when directly linked to the safety of persons, their design and installa-
tion are strictly regulated.
CERTIFICATION OF SAFETINEX PRODUCTS
Safetinex products satisfy all the requirements of category 2, PL c, ac-
cording to EN / ISO 13849 - 1:2006 (formerly EN 954-1) and Type 2
according to EN / IEC 61496 - 1 and - 2.
Before considering the use of Safetinex products in machine safety ap-
plications, it must be verified that the product certifications are valid in
the country where the product is to be used.
The following chapters provide a brief introduction to the main stand-
ards and regulations applicable in the European Community and in
North America. They are by no means a complete guide and only serve
as a reminder of the most important issues. For detailed information,
please refer to the original documents.
This section is intended to provide help for designers and users of in-
dustrial machinery. It summarizes the basic principles of European di-
rectives, procedures and regulations in terms of protection against haz-
ards in the work environment. It is by no means a complete guide and
only serves as a reminder of the most important issues. For detailed
information, please refer to the original documents.
TYPES OF SAFETY STANDARDS APPLICABLE IN
THE EU
In the European Union, safety is legislated. The EU’s Machinery Direc-
tive requires that all machines and safeguarding devices operating in
EU countries meet essential safety standards. Harmonized European
standards regarding machine safety policies are prepared by the CEN
(European Committee for Standardization) or CENELEC (European
Committee for Electrotechnical Standardization) and finalized by the
EU Commission. Once ratified, these standards become European
Standards (EN) that take precedence over national laws. Thus, EU
countries must remove or modify any national standard that conflicts
with the European Standard. CENELEC and CEN cooperate closely
with ISO and IEC, the main bodies for international standards.
EUROPEAN
SAFETY STANDARDS

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Applicable standards usually have the prefix EN (“European Norm”),
but most also have international – ISO/IEC – equivalents. There are
different types of standards:
–A-type standards are basic safety standards applicable to all ma-
chinery, e.g. EN/ISO 14121
–B1-type standards set out special safety aspects and procedures,
e.g. EN/ISO 13849-1
–B2-type standards set rules on safety equipment design, e.g. EN/
IEC 61496-1, EN/TS/IEC 61496-2/-3
–C-type standards set safety requirements for a specific machine or
type of machine
EXAMPLES OF SAFETY STANDARDS
In addition to the Machinery Directive 2006/42/EC and the Work Equip-
ment Directive 89/655/EEC, there are standards that specifically focus
on protective equipment, such as:
TYPE SCOPE CE
STANDARDS
INTERNATIONAL
STANDARDS
A Safety of machinery
Basic principles
EN 12100-1
EN 12100-2
ISO 12100-1
ISO 12100-2
Risk assessment EN 14121-1
EN 14121-2
ISO 14121-1
ISO 14121-2
B Interlocking devices EN 1088 ISO 14119
Guards EN 953
Safety related parts of
control systems
EN 13849-1
EN 13849-2
ISO 13849-1
ISO 13849-2
Safety of machines:
Electro-sensitive
protective equipment
EN 61496-1
CLC/TS 61496-2
CLC/TS 61496-3
CEI 61496-1
CEI 61496-2
CEI 61496-3
Safety distance details EN 13855 ISO 13855
Positioning of protective
equipment EN 13855 ISO 13855
TABLE 1: EXAMPLES OF SOME APPLICABLE SAFETY STANDARDS
For additional information regarding European standards, please refer
to, www.cenorm.be, www.cenelec.be, www.din.de, www.iec.ch, www.
iso.ch.
AN APPROACH TO EUROPEAN STANDARDS
The European Union has chosen to regulate the production, installation
and use of old, modified and new machines within the European Union
territory by approaching the parties concerned separately, i.e. one legal
framework has been created for users and another for manufacturers.

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The Work Equipment Directive sets out the rules applying to users of
machines on production sites, while the Machinery Directive sets out
those applying to machine constructors and safety equipment manu-
facturers. However, most subordinate standards apply to both parties,
as shown in the following chart.
THE USER SIDE
The user side is regulated by the Work Equipment Directive, which
states that users of a machine are obliged to make sure that it complies
with the legal requirements. Hence, if the user buys a machine which
does not comply with the EU Machinery Directive, it is his responsibility
to take the necessary actions to bring the machine up to the required
quality and safety level.
Additionally, the Work Equipment Directive specifies what minimum
regulations must be observed for safety purposes when work equip-
ment is being used. The original text can be found on the relevant Eu-
ropean Union website.
TABLE 2 : EUROPEAN MACHINE SAFETY OVERVIEW – USER AND MANUFACTURER SIDE.
USER SIDE MANUFACTURER SIDE

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MACHINE MANUFACTURER SIDE
The manufacturer side is addressed by the Machinery Directive. This
umbrella document refers to the specific requirements described in EN
standards, and stipulates that each danger zone of a machine must be
made safe. The method used to make different zones safe depends on
the type of hazard.
The Machinery Directive requires that, before placing machinery on
the market and/or putting it into service, the manufacturer ensures that
a technical file is made available. This technical file shall comprise a
construction file including, among others, “the documentation on risk
assessment demonstrating the procedure followed, including:
(i) a list of the essential health and safety requirements which apply to
the machinery,
(ii) the description of the protective measures implemented to eliminate
identified hazards or to reduce risks and, when appropriate, the indi-
cation of the residual risks associated with the machinery.” (Machin-
ery Directive 2006/42/EC, Annex VII, A, 1, a)
Machines that are highly hazardous (as listed in Annex IV of the Ma-
chinery Directive) must conform to special procedures. The manufac-
turer is responsible for obtaining conformity through various procedures
that may require examination of the machine by an EU notified body.
NOTIFIED BODIES
In order to have control over the execution of these directives, veri-
fication of certain steps by certifying bodies may be imposed by the
directives. For example, all safety device concepts must be analyzed,
checked and tested by such a third party organization. In many cases,
this third party organization also audits the production process of a
safety device manufacturer.
A notified (or certified) body is a certification, inspection or testing body
designated by the notifying authority of an EU member state to issue
attestations of conformity for products. Each EU member state has a
list of notified bodies authorized to issue EU-type examination certifi-
cates. The lists include the identification number of each notified body,
as well as the specific areas of activity and the tasks for which it has
been designated.
European notified bodies responsible for carrying out conformity as-
sessment procedures can be found through the NANDO (New Ap-
proach Notified and Designated Organizations) website, where accred-
ited bodies can be searched for by country, product or directive. An
official list of notified bodies responsible for assessing products in com-
pliance with the Machinery Directive can also be found on the relevant
European Union website.

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This section is intended to provide help for designers and users of in-
dustrial machinery. It summarizes the basic principles of North Ameri-
can regulations and standards in terms of protection against hazards in
the working environment. It is by no means a complete guide and only
serves as a reminder of the important issues. For detailed information,
please refer to appropriate agencies and documents.
A DIFFERENT APPROACH
Whereas European standards are mainly machine manufacturer ori-
ented, North American standards are primarily directed towards users.
Unlike in the EU, third party certification is not mandatory in the US or
Canada. In terms of liability, it is the employer’s responsibility to prove
that he has done his utmost to ensure his employees’ safety. However,
certification has become a strong commercial asset in terms of market
requirement. On users’ request, national compliance agencies assess
and grant the required certification.
Although the US and the EU have different methods for developing and
applying standards, their purpose is the same, namely to ensure an ap-
propriate level of safety in the workplace. Harmonized standards have
the advantage of promoting world trade and reducing duplication of ef-
fort. Harmonized international standards allow manufacturers to access
many markets with one product. Users profit from competitive products
that meet uniform quality and functional requirements – wherever they
were manufactured.
In the United States, standards are developed and enforced both by
governmental agencies and industry groups. US employers, install-
ers or OEMs are legally responsible for compliance with all applicable
regulations, both national and international. In the US, the Occupational
Safety and Health Administration (OSHA) is a federal agency that can
enforce its regulations through penalties and fines.
OSHA REGULATIONS AND U.S. CONSENSUS
STANDARDS
The Occupational Safety and Health Act passed on Dec. 29, 1970 es-
tablished guidelines for safe and healthy working conditions.
Occupational and Health Standards in the U.S. are defined in Title 29 of
the Code of Federal Regulations Part 1910. Subpart O of this document
deals specifically with machinery and machine guarding, and defines
the general requirements for all machines (1910.212) and for some
specific types of machinery.
Encouraged and assisted by OSHA, more than half of the US states
have developed their own safety and health programs and regulations
which are then enforced by OSHA as “National Consensus Standards”.
Information on both state plans and OSHA regulations may be obtained
from their respective websites.
OSHA uses national consensus standards to further define machine
protection requirements in addition to subpart O. In 1910.212, it states
that “The point of operation of machines whose operation exposes an
NORTH AMERICAN SAFETY
STANDARDS
FIG. 3 : APPLICATION EXAMPLES OF YBB
DEVICES

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employee to injury, shall be guarded. The guarding device shall be in
conformity with any appropriate standards therefore, or, in the absence
of applicable specific standards, shall be so designed and constructed
as to prevent the operator from having any part of his body in the dan-
ger zone during the operating cycle.”
“Any appropriate standards” refers to national consensus standards
generally recognized in the industry. Bodies frequently referenced by
OSHA include the American National Standards Institute (ANSI), the
National Fire Protection Agency (NFPA), Underwriters Laboratories
(UL) and the American Society of Mechanical Engineers (ASME).
As an example, ANSI B11.1 sets safety requirements for mechani-
cal power presses, ANSI B11.15 specifies standards for pipe bending
machines, ANSI B11 TR.1 gives ergonomic guidelines for the design,
installation and use of machine tools, and ANSI/RIA R15.06 stipulates
the safety requirements for industrial robots. Please consult national
consensus standards bodies for complete listings.
NORTH AMERICAN STANDARDS FOR SAFETY
ISSUES: UL, ANSI AND CSA
AMERICAN STANDARD AGENCIES
UL STANDARDS
Underwriters Laboratories Inc. is a testing organization established in
1894 and is authorized to conduct certification testing of any electrical
device. Although UL certification is not mandatory, many companies
strive to obtain its certification for products aimed at the U.S. market.
UL certification has two levels, namely listing certification, generally for
final products, and recognition certification, for parts or components
built into a product. Once a product has obtained UL certification, addi-
tional on-site inspections are carried out on a quarterly basis to ensure
that the production plant continues to manufacture products conforming
to UL standards.
Since the purpose of UL standards is to eliminate the danger of fire or
electric shock caused by electrical appliances, in principle only those
appliances presenting such risks are subject to this certification.
For more details on the UL Standards, please consult the UL website.
ANSI STANDARS
The American National Standards Institute was founded in 1918 to
manage the standardization system in the US. It is not ANSI’s task to
create standards of its own, but rather to approve the standards set up
by specialized organizations. Many UL standards have been converted
into ANSI/UL standards.
For instance, ANSI standards include ANSI B 11.19: Standard for per-
formance of safeguarding devices and ANSI/RIA R15.06: Standard for
robot safety.
For more details on the ANSI Standards, please visit the ANSI website.

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CANADIAN STANDARD AGENCIES
CSA STANDARDS
The Canadian Standards Association is an organization that admin-
isters and coordinates the standardization system in Canada. Cross-
certification between the U.S. and Canada has been granted, based on
the Mutual Recognition Agreement (MRA).
Electrical appliances connected to a public power source in Canada
must conform to CSA Standards. Manufacturers of these products need
to obtain C-UL or CSA certification, or the seller needs to apply for cer-
tification directly to the provincial authorities.
For more details on the CSA Standards, please visit the CSA website.
INTERNATIONAL STANDARD AGENCIES
International standards also play a significant role in North American
machine safety. The two main international entities are the Internation-
al Electrotechnical Committee (IEC) and the International Standards
Organization (ISO). IEC is a recognized provider of standards in the
electrotechnical field and is composed of national electrotechnical com-
mittees. ISO is an international federation of national standardization
bodies. ISO and IEC influence international standards through formal
relationships. In the US, ANSI coordinates with ISO and IEC through
technical advisory groups (TAG).

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DEFINITION OF HAZARDS AND RISK
REDUCTION STRATEGY
EN/ISO 12100 serves as a basis for all subsequent standards. It de-
scribes every type of hazard that needs to be considered in terms of
machine safety. Exposure to hazards includes numerous potential situ-
ations that must first be identified.
Mechanical hazards may result in crushing, shearing, cutting/severing,
entanglement, drawing-in/trapping, impact, stabbing/puncture, friction/
abrasion, injuries due to high pressure fluid ejection, etc. Machine haz-
ards are also influenced by sharp edges, vibrations and unstable or
moving objects. The list quotes electrical and thermal hazards, radia-
tion, dust and hazardous substances (gas, vapors). In terms of ergo-
nomics and the working environment, there are risks of falling, tripping
or slipping. A combination of hazards may result in a specific new haz-
ard.
EN/ISO 12100 subsequently gives general guidelines for eliminating or
reducing hazards through prevention and protection. It is recommended
to use technology that avoids most of the problems linked with the haz-
ards listed above. Any decision that contributes to prevention against
hazards is part of the security process and risk reduction strategy.
In this respect, taking ergonomic principles into consideration is im-
portant. A high level of automation will not only help operators, it will
also increase productivity and reliability. Reducing unnecessary human
movements and efforts can contribute to a safer working environment.
Proper lighting of the work place will help to minimize hazards.
Operators must be able to stop machines at any time in case of an
emergency. Starting and/or restarting the machine after an interruption
must be carefully planned. When programmable electronic safety sys-
tems are used, the behavior of such systems in case of defect and the
protection of the software requires particular attention.
RISK ASSESSMENT PROCESS
In essence, conducting a risk assessment involves identifying hazards,
evaluating the potential severity of harm and identifying measures and
solutions for eliminating or reducing such risks.
This requirement is stated in U.S. standards (Title 29 US Code of Fed-
eral Regulations, Part 1910, Subpart O).
For more details, please refer to the following documents:
–OSHA 3071, Job Hazard Analysis
–ANSI/RIA R15.06-1999, Safety Requirements for Industrial Robots
and Robot Systems
–ANSI B11.TR3, Risk Assessment and Risk Reduction
–EN/ISO 14121, Principles of Risk Assessment. EN/ISO 14121 re-
fers to additional standards, such as EN/ISO 13849-1 and EN/ISO
12100
RISK ASSESSMENT
EN/ISO 12100

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The following chart, based on EN/ISO 12100-1 and ANSI B11.
TR3:2000, can be used to carry out risk analyses and ensure that all is-
sues have been thoroughly considered. This iterative process must be
carried out for every machine operating in the work place, as well as for
all the potential hazards associated with each machine.
This risk analysis and assessment process helps to take all the different
aspects of potential machine hazards into consideration. It is important
to document this procedure as evidence that the task has been fully
carried out and to allow others to check it or use it for further improve-
ments.
DIAGRAM 1: RISK ASSESSMENT PROCESS

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EN/ISO 14121 also describes procedures for identifying hazards and
assessing risks, and provides guidance on the information required to
achieve this goal. The process involves analyzing the risks in a sys-
tematic and documented way, in order to eliminate or reduce hazards.
Qualitative and quantitative methods can be used.
All aspects of potential hazards must be taken into consideration:
–The phases of a machine’s life
–The full range of foreseeable uses and misuses of a machine
–All persons possibly exposed to hazards when the machine is being
used
Risk is defined as a function of the severity of possible harm and the
probability that such harm occurs (frequency and duration of exposure,
possibility of avoiding harm, etc.). One important piece of information is
the history of accidents, if available.
Among the aspects to be considered when establishing elements of
risk, the analysis should account for
–Different types of exposure depending on the type of work (setting,
teaching, operating, cleaning, etc.)
–Human factors, such as applicability and ergonomic issues
–The reliability of safety functions, including their maintenance
–The possibility to defeat or circumvent safety measures
EN/ISO 14121-1:2007 gives a full list of hazards referenced by EN/
ISO 12100.
In addition, the safety of any machine will diminish with time due to the
deterioration of components, wear, loosening of parts, etc. It is there-
fore important to conduct regular inspections in order to detect defects
that may lead to reduced safety, and to effect the necessary repairs
before the level of risk exceeds the original assessment.
EN/ISO 14121

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METHODS FOR DETERMINATION OF RISK
LEVEL
The methods used for assessing the risks associated with a specific
machine are addressed by several standards. Standards either impose
or recommend corrective measures that will establish an adequate
level of safety.
DETERMINATION OF RISK LEVEL IN NORTH AMERICA
In order to select the appropriate safety device adapted to the actual
risks and dangers, it is important to assess the risk. ANSI B11.TR3-
2000 provides a “Risk Estimation Matrix” in order to determine the level
of risk depending on the cross-referenced factors of the probability of
harm occurrence and harm severity:
PROBABILITY
OF HARM
OCCURRENCE
SEVERITY OF HARM
CATASTROPHIC SERIOUS MODERATE MINOR
Very Likely High High High Medium
Likely High High Medium Low
Unlikely Medium Medium Low Negligible
Remote Low Low Negligible Negligible
TABLE 3 : RISK ESTIMATION MATRIX AS PRESENTED BY ANSI B11.TR3-2000
The purpose of assessing the risk is to determine the appropriate level
of safety. It is important that the protective device complies with the
determined risk and is adapted to the machine control system. Risk
assessment applies to each element that makes up the safety system,
and not just the protective device itself. In particular, safety devices can
only be used on machines that comply with control reliability as de-
scribed in OSHA 29.1910.212 and ANSI B11.19-20.
Another important point to be considered is the life cycle of the machine
and its protective devices. The safety of any machine will diminish with
time due to the deterioration of components, wear, loosening of parts,
etc. It is therefore important to conduct regular inspections in order to
detect defects that may lead to reduced safety, and to effect the neces-
sary repairs before the level of risk exceeds the original assessment.
DETERMINATION OF REQUIRED PERFORMANCE LEVEL (PLr)
EN/ISO 13849-1 sets out a procedure for the selection and design of
safety measures. The procedure contains the following 6 steps:
1. Identify the safety functions to be performed
2. Determine the required Performance Level
3. Design and technical realisation of the safety functions
EN 13849

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Contrinex Industrial Electronics
4. Evaluate the achieved Performance Level
5. Verify the achieved Performance Level
6. Validate that all requirements are met
Based on risk identification, the required performance level of risk re-
duction is determined using the following graph sourced from EN/ISO
13849-1, Annex A.
The objective is to determine the required performance level PLrthat
sets the requirements of the necessary safety system, depending on
the risks involved in each case. As described below, three parameters
are taken into consideration:
1. The potential severity of the harm
2. The frequency and/or duration of exposure to the hazard
3. The possibility of avoiding the hazard
DIAGRAM 2: REQUIRED PERFORMANCE LEVEL
PLr
L
H
P2
F2
S2
P1
P2
F1
P1
P2
F2
S1
1
P1
F1
P2
P1 a
b
c
d
e
1 starting point for evaluation of safety function contribution to risk reduction
S severity of injury:
S1 slight (normally reversible injury)
S2 serious (normally irreversible injury or death)
F frequency and/or exposure to hazard:
F1 seldom-to-less-often and/or exposure time is short
F2 frequent-to-continuous and/or exposure time is long
P possibility of avoiding hazard or limiting harm:
P1 possible under specific conditions
P2 scarcely possible
PLrrequired performance level
Low contribution to
risk reduction
High contribution
to risk reduction
In order to reduce the determined risk (PLr) to an appropriate level, a
safety system with performance level PL ≥PLrneeds to be properly
implemented. A corresponding average probability of dangerous failure
per hour (PFHD) can be associated with each performance level:

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PERFORMANCE LEVEL (PL) AVERAGE PROBABILITY OF DANGEROUS FAILURE PER HOUR
a 10-5 ≤PFHD< 10-4
b 3 x 10-6 ≤PFHD< 10-5
c 10-6 ≤PFHD< 3 x 10-6
d 10-7 ≤PFHD< 10-6
e 10-8 ≤PFHD< 10-7
TABLE 4 : AVERAGE PROBABILITY OF DANGEROUS FAILURE PER HOUR
All Safetinex Type 2 AOPDs fully comply to Performance Level c. For
details, please consult the product data sheet.
SPECIFIC STANDARDS FOR SAFETY DISTANCE CALCULATION
EN/ISO 13855 gives details concerning the positioning of safeguards
with respect to the approach speeds of parts of the human body.
INSTALLATION RULES
All safety equipment has to be installed following the strict installation
instructions given by the manufacturer and the applicable standards.
Without proper installation, the safety device cannot fulfill its function
and will give a false impression of safety to persons approaching a dan-
gerous machine. EN/ISO 13855 defines the installation requirements
for safety light curtains and access control barriers with respect to the
approach speeds of parts of the human body. Below is a summary of
the key concepts.
POSITIONING THE AOPD
The level of safety depends on the way the device is positioned. The
risk assessment conclusions will help decide what position is best suit-
ed for preventing foreseeable hazards. In order to ensure proper safe-
guarding, special care must be taken to find the position that will not
allow the protective device to be bypassed and such that any hazard-
ous machine movement is safely stopped before potential harm occurs.
There are different classical ways to position safety light curtains:
–Vertically (“perpendicular approach”)
–Horizontally (“parallel approach”)
–In an L shape (vertically and horizontally combined)
–Inclined (“angular approach”).
It must not be possible to pass over, below, around or go behind the
protective field. When positioning access control barriers, it must not
be possible to pass over the highest beam, below the lowest beam or
between two beams. If this cannot be guaranteed, then additional pro-
tective devices must be used.
INSTALLATION
EN/ISO 13855
EN/ISO 13855