Machine Safety Training for
Beginners
Introduction to Machine Safety
Contents
●Introduction to Machine Safety
●Annexes:
●Additional Products Info
●Standards
●Safety Principles
Schneider Electric - Division - Name – Date
2
Introduction to Machine Safety
Safety basics and offer presentation
Danger and Risk
● Most people have a misunderstanding between danger / hazard and
risk. A danger is ever present whereas risk is the possibility of that
danger happening.
Consider the following two statements:
● A hungry tiger is dangerous
● A hungry tiger is risky
● A hungry tiger is dangerous, but it is only a risk if it is in your vicinity.
● We can avoid or reduce risk by bounding danger
(tiger is locked in the ZOO, so the risk to be attacked is very low)
Risks are events or conditions that may occur, and whose occurrence, if it does
take place, has a harmful or negative effect
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Protect People and Increase Productivity
●Investing in machine safety
● Health & safety for all personnel
●
Cut costs associated with:
● Physical injuries
● Insurance premiums
● Lost production, penalties
●…
●
Increased productivity
due to the prevention of accidents
● Better failure detection
● Worker confident at work
● Improving maintenance efficiency
●…
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Safety - Acceptable Risk Level
● Risk 0 does not exist but it must
be reduced up to an acceptable
level
● Safety is the absence of risks
which could cause injury or
damage the health of persons.
● It’s one of the machine designer
job to reduce all risks to a value
lower than the acceptable risk.
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Machine Safety as Global Concept
●Safety must be taken into
account:
● already in the design phase
● and must be kept in place throughout
all stages of a machine’s life cycle:
> Transportation
> Installation
> Adjustment
> Operation, Production
> Maintenance
> Dismantling
Design and
production
Operation
Installation and
implementation
Maintenance
●Safety is necessary to obtain
CE mark
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Safety Chain Principle
Use devices that
comply with
safety standards
Catch the
information
Monitor & analyze
the information
Stop the dangerous
machine
Safe signal transmission
Safety-oriented
signal processing
Emergency stop
operations
Signaling
Disconnection
and locking
power supply
Safe drive
technology
Initializing & control
of hazardous machine
Safeguarding to protect
people from hazard
Safe connection & communication of functional units or segments
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Preventa - Your Full Safety Chain Solution
● Catch the information
● Emergency stop/ Trip wire
● Control of access of hazardous zones
●Occasional
●Free to continuous
● Starting & enabling of dangerous
movements
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Preventa - Your Full Safety Chain Solution
● Monitor the information
● Safety modules
● Controllers
● Safety PLC
● ASi safety at work
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Preventa - Your Full Safety Chain Solution
● Stop the machine
● Variable drives
● Vario
● Contactors
● Audible and visible warnings
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European legislation and the standards
● The EU Machinery Directive (98/37/EC),
● As a European law, defines the targeted levels of Machine Safety.
● Compliance with machinery directive is necessary
● to get the CE mark, and to Allow the free circulation of machinery within
the European Union.
● A new version will be effective at the end of 2009
● The European harmonised standards
● Established technical specifications which comply with the requirements of
the related directives.
● Compliance with European Harmonised standard give compliance with the
related directive
●Comply with the European harmonized Standards is
the simplest way to comply with the Machinery
Directive
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The Process to Comply with CE Marking
+info
+info
+info
+info
+info
+info
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+info
13
Additional
offer info
Safety Switches offer
Guard switches
Safety switches
with rotary or spindle actuator
Limit switches Coded magnetic
Heavy Industrial Machines (Metal enclosure)
XCS A / B / C / E
XCS D / M
Light Industrial Machines (Plastic enclosure)
XCS MP / PA / TA / TE
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XCS PL / TL / TR / PR
XCS P
XCS DM / DM3 / DM4
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Additional
offer info
Safety Mats offer
XY-TP2
XY-TP3
XY-TP4
500x750 mm
750x750 mm
750x1250 mm
XY-TP1
500x500 mm
All pieces can be electrically interconnected
depending on the shape and size needed to protect
from accessing danger area
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Additional
offer info
Light Curtains offer
Type 4
Type 2
Body protection
Finger and Hand protection
Hand protection
Body protection
XPS-CM
XUS-LDS
cascadable
XUS-LDM segments
XUS-LB
Sn: 0.3…20 m
38 mm X 50 mm
XUS LPDM
Programming and
Diagnostic Module
2x PNP + 1x PNP
(or NPN)
IP65
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XUS-LPZ
XUS-LPB
2 versions are possible:
- active (left) receiver
Sn: 0,8…70 m
- passive (right) rcvr
Sn: 0,8…8 m
52 mm X 55 mm
2x PNP + 1x PNP
IP67
Compact model
XUS-LNG
XU2-S
XU2-S
Sn: 0.3…15 m
Sn: 0,75…1,2 m
28.5 mm X 32 mm
Diam 18
2 solid-state PNP
2x N/O + 4x PNP
IP65
IP67
Slim model
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Modular beam
Positioning of the Safety Solutions
Safety
Safety
System
Centralised I/O
Process and
Safety Island
Multiple
Safety
Functions
One Safety
Function
Decentralised I/O
Repetitive
Machines
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Simple
Machines
Complex
Machines
Manufacturing
Process
Batch
Process
Machine
Complexity
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Safety Processing Devices offer overview
Non-configurable
modules
Configurable controllers
No software
XPS-A/B/C/D/T/V
1 safety
function
With software
Programmable
PLCs
XPS-MP
XPS-MC
ASISAFEMON
XPS-MF
2 independent
functions
Multiple
independent
functions
1 or 2
independent
functions
Multiple
functions
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Additional
offer info
Safety PLC offer
Compact Solution: 90% of
applications
- Wiring cost reduction
- Network flexibility
XPSMF40
Safety PLC
Digital
IO
XPSMF35
Digital &
Safety PLC Analogue IO
XPSMF30
Safety PLC
Digital
IO
XPSMF31
Safety PLC
Digital
IO
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Safety
Remote IO
XPSMF1
Digital
Input
Modular Solution: 10% of applications
– Speed: Response time
– Large application memory
– High network flexibility
XPSMF IO Cards
Digital: Input; Output;
Input & Output
Analogue: Input;
Output
Counter Input
XPSMF2
Digital
Output
XPSMF3
Input &
output
Rack
Power
supply unit
Central processing unit
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Safety Controller offer
XPS MC
Additional
offer info
XPS MP
Bus connection
Modbus
Modbus,
CANopen
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Modbus,
Profibus DP
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Additional
offer info
Safety Modules offer
XPSAC XPSAF XPSATE
XPSAV XPSAFL XPSAR
XPSAK
XPSECM
XPSECP
XPSVC XPSBA XPSBC XPSBF
Time Delay fnc
4 or 8 N/O
E-stop, Switch,
Trip-wire
Two-hand control
stations
Additional safety
contacts modules
Light
curtains
XPSLCD
XPSLCM XPSCM XPSDMB XPSDME
Type 2 or Type 4
Light
curtains
XPSTSA
XPSTSW
XPSVNE
XPSDA
XPSPVT
XPSPVK
XPSOT
Type 2
Single
Single
beam
beam
sensors sensors
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For applications
requiring safety
time delay
Zero
Lifts
speed
control
detection
Press application
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Additional
offer info
AS-i Safety@Work offer
ASI SSSLB
Emergency
Stop
ASI SSLC
M12 entries
Network
ASI SSLLS
ISO M16 entry
ASI SE
ASI SSL
Control stations
ASI SAFEMON..
ASI SA01
Category 4
monitor
Analyser
ASi-Safety at Work on the standard ASi cable
ASI TER
Slave
Monitor
Software
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Management
Safe and logical functions
Adjustment
terminal
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Safety Dialogue Solutions
E-stop and Trip wire switches
Emergency stop function to
avoid the accident or reduce
it’s consequences
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Two-hand control
Enabling grip switch
Authorize starting of a
Allow access to a
dangerous machine
danger zone and stop
movement once people are the machine when it is
outside the danger zone
not actuated
Foot switches
Start or Stop
the machine
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Additional
offer info
E-stop and Trip wire offer
● Emergency Stop
pushbuttons for:
● machine tools,
● foundries, presses,
● automobile industry
● Emergency Stop
pushbuttons for:
● Control stations for:
● assembly and
packaging machines
● paper, cardboard and
woodworking machines
● food/beverage
processing and
chemical industries
● assembly and packaging
machines,
● paper, cardboard and
woodworking machines,
● food/beverage processing,
chemical and automobile
industries, mechanical
presses
Metal bezel and fixing collar
Plastic bezel and fixing collar
Plastic enclosure
XB4 B
XB5 A
XAL K
● Trip wire switches for:
● conveyor systems,
● materials handling,
machine tools,
● electrical testing
stations
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Protection ≤15 m
XY2 CH
Protection ≤50 m
XY2 CE
Protection ≤100 m
or 2x 100 m
XY2 CB
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Two-hand Control Station, Enabling
Control and Signaling offer
Switch and Foot Switch offer
Two-hand Control Station
Additional
offer info
Enabling Switch
Additional
offer info
XY2 SB
Single pedal switches - Metal
Double pedal switches - Metal
XY2 AU
Single pedal switches - Plastic
XPE Y
XPE A
XPE G
XPE B
XPE R
Additional
offer info
Schneider Electric - Division - Name – Date
XPE M
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Mini-Vario and VARIO Switch
Disconnectors
Front Mounting
Additional
offer info
Enclosed
VCCD / VCCF
Backplate
mounting in
enclosure
VCFN /
VCF*
VCD / VCF
Door mounting
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Reminder
●The safety chain protects your personnel,
material and increases your productivity
●Safety must be taken into account from the
design stage to end of the life of your
installation
●Schneider Electric offers complete safety chain
solutions
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T hanks
for your attention
Schneider Electric - Division - Name – Date
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Additional Products Info
Safety Switches
● Working principle:
● The start command for the machine can only be initiated following correct operation of
the guard switch.
● On its release, the N/C safety contacts are opened by positive action or, for coded
magnetic switches, change state (must be monitored using a PREVENTA safety
module)
● Advantages:
● The guard only has to move a small distance
for the switch to be activated.
● Ideal for:
− Guards without hinges or guides connecting
them to the machine
− Guards that can be disassembled without tools
Guard
Open
Closed
Key
● Disadvantage:
● Can be bypassed if an actuator key not attached
to the guard is used
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Key
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Functionality
● Actuator Key
● Common to all metal or plastic case safety switches
● Square turret head which can be rotated through 360° in 90° steps
● Contact states remain unchanged when loosening the
fixing screw (head remains attached to the body)
● Safety of operation
● 3-pole contacts for metal cases and 2-pole or 3-pole for plastic cases
● Without or with intelocking and locking of actuator by solenoid
● Manual locking/unlocking by pushbutton or key operated lock
● Correspondence to environment
● XCS metal for heavy duty environment
● XCS plastic for light and normal environment
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Functionality - Lever or Spindle
● Application
● Immediate stopping of the dangerous movement as soon as the lever or spindle
reaches an angle of +5° or -5° from the home point 0°
● Degrees of freedom
● Lever-operated XCSPL and XCSTL: +180°, +/-90° or -180° depending on the product
reference
● Spindle-operated XCSPR and XCSTR: +/-270°
● Levers – Straight or elbowed, making the lever switches suitable
for use with all types of hinged guards:
● flush with the machine framework (use a switch with an elbowed flush lever)
● overhanging in relation to the machine framework (use a switch with a straight lever)
● Spindle operators
● 2 spindle lengths: 30 or 80 mm
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Coded magnetic Switches and Systems
● Plastic case system for use on machines with low inertia
(quick rundown times)
● Coded Magnetic Switches
● 2-pole (XCS DMC/XCS DMR/XCS DMP) or 3-pole (XCS DMP) contacts
● In safety circuits must always be used in conjunction with a Preventa safety
module
● Coded Magnetic Systems
● Self-contained range: category 3 (SIL 2) XCS DM3 and
category 4 (SIL 3) XCS DM4
● Integrated self-monitoring using micro-processors, no need to use external
safety module
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Mounting and Directions of Approach
XCS-DM3 /4
● 3 options for transmitter/receiver mounting: face to face, side to side,
face to side
● 2 directions of approach for each type of mounting (except XCS-DMR)
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Functionality – Coded Magnetics 1
● Working principle – Reed Switch:
● Use Reed technology: contact
activated by magnetic field
● Composition: A pair of ferromagnetic
blades encapsulated in a hermetically
sealed glass tube containing inert gas
which prevents any oxidation/corrosion
of the blades
Coded magnets
S
N
N
S
S
N
=
Safety output contacts
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Functionality – Coded Magnetics 2
● Working principle – Hall Effect:
● The receiver part has a conductor (Hall element) with an established current
flow
● The presence of a perpendicular magnetic field will cause a difference of
potential on opposite edges of the hall element, this is what is known as the
Hall Effect
● In the absence of a magnetic field, the measured voltage is insignificant
● The hall voltage is directly proportional to the strength of the magnetic field
Hall Voltage
1 – Electrons
2 – Conductor (Hall sensor)
3 – Magnet
4 – Magnetic field
5 – Power supply
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Image source = Wikipedia
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Miniature Safety Limit Switches
● With head for linear movement (plunger) or rotary movement (lever)
● narrow metal miniature case XCS M
● compact metal XCS D or plastic XCS P case
● With protective plate, preventing both access to the fixing screws or
adjustment of the head by no authorised personnel.
● Torx fixing screws.
● Used for machines without or with low inertia:
● Used in pairs, with one switch in positive mode,
and the other in negative mode
● In combined mode, they can, when connected to
Preventa modules, provide a Category 4 safety control system
back
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Safety Mats
● The safety mats function is to protect operator in front of the
dangerous machines in the harsh environnent (where optical solution
can‘t be used)
● Features
● Detect of people or objects weighing more than 20Kg crossing or falling on
the mats surface
● Modular surface – electrically interconnectable, without loss of sensitivity
● “Protect Area Design” software configuration tool is available for
simplification of installation
● Simple wiring
● Insensitive to dusty environment
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Safety Mats Characteristics
● A safety mat comprises:
● a sensing zone 1
● a border comprising aluminium rails 2
● and rail corners which secure the assembly 3
● Working principle:
● Two stainless steel plates separated by polyurethane foam
● On activation (object on mat) short-circuit between plates will be detected
● Advantages
● Rigidity for transport
● Detection at any point
● Disadvantage
● Too heavy objects can damage plates and they
will short-circuit permanently (max. load 800N/cm2)
However, the short-circuit guarantees tripping safety
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Protect Area Design software
● Main function:
● Creation of an application based on light curtains and/or
safety mats
● Benefits:
● Quick chose of the products needed for the application
● Huge winning time compare to the application manage without
PAD* software
● Allow, with the “SysQuote” software associated in
option to quote the complete applications
● Results:
● Component selection (products description)
● Graphical representation of the configuration
● List of selected components (references and
quantities)
● Configuration of products
back
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Light Curtains
● This is an electro-sensitive optical safety device used to protect
people working near dangerous machines.
● When the light curtain senses entry into the protected zone by an object, it
sends a stop signal to the guarded machine
● Light curtains can replace mechanical guards IF the operating
environment is not polluted (splashing, spattering etc. )
● Facilitate operator’s work if frequent access to the danger zone is needed
● Easier access for maintenance operations
● Applicable for machines where dangerous movement can be
stopped quickly
● Mechanical and hydraulic presses
● Molding presses
● Stamping, forming and automated assembly machinery
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Light Curtains System Components
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Light Curtains Characteristics
● Detection Capacity (d) is the smallest object
(diameter) that safety light curtain is capable of
detecting with absolute certainty (finger, hand or
body detection)
d=P+e
● P - distance between the axis of 2 adjacent beams
● e - diameter of the beams
d  14 mm – finger
d  30 mm – hand
d  70 mm – body
● Protected Height (Hp) is the zone (or height) within
which an object of equal diameter to the detection
capacity d is detected with absolute certainty
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Light Curtains Standard Functions – 1/2
● Automatic/Manual protection mode is what standard EN/IEC 61496
calls start (or restart) interlock of the safety light curtain
● in AUTO mode: on power-up or after the beams have been cleared, the light
curtain resets itself automatically
● in MANUAL mode: on power-up or after the beams have been cleared, the
light curtain keeps its output safety circuits in the “open” position. Pressing
(and releasing) the reset button will cause actual resetting of the light curtain
● Monitoring of external switching device (EDM - External Devices Monitoring)
● consists of monitoring the function (open or closed), together with the time
taken to reach that condition, of the machines power switching components
(contactors)
On power-up, the XUS-L system looks for an EDM closed condition. If this is found, it will enter a state
consistent with the selected operating mode. When the XUS-L system enables its safety outputs, it monitors
the EDM for a closed-to-open transition. This transition must occur within 300 ms or the XUS-L system
considers the EDM alarmed and will then enter an alarm state.
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Light Curtains Standard Functions – 2/2
● Test function is a feature that allows a machine controller to simulate
an interruption of the sensing field.
● The order to start the test is given by the machine during a non-hazardous
phase in which it performs a self-test of the entire safety system including
the light curtain (ex., on power-up)
● If the result of the test is not conclusive, the light curtain controller sends a
stop signal to the connected machine
● Response time – the maximum time between detection of the beam
being interrupted and the change in state of the OSSD of the light
curtain
● OSSD – Output Switching Safety Device
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Light Curtains Specific Functions – 1/3
● Muting is the temporary automatic disabling of the light curtain’s
detection function, which allows objects to access the hazardous zones
during the process without stopping the machine
● Activation (or deactivation) is achieved by means of standard sensors
(photo-electric or other)
● When activated, a signal is sent to the automation system and signaling
informs the operator that they are not protected
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Light Curtains Specific Functions – 2/3
● Blanking is the disabling of a selected group of light beams in the light
curtain (and not all the beams as with muting)
● This function allows the presence of objects during process operations
● Caution when using:
● The detection capacity changes  This imposes a greater safety distance
● Additional protection is necessary on each side of the "blanked" zone, in
order to prevent any intrusion into the free areas
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Light Curtains Specific Functions – 3/3
● Floating Blanking – is the inhibition of one or two light beams
(adjacent or otherwise), anywhere in the light curtain
● An obstruction can move or "float" inside the sensing zone without
generating a stop signal
● Blanking plus floating blanking
functions can be combined. This prevents the light curtain from being
accidentally tripped if the part blanking the beam starts to vibrate
(making it interrupt or trigger the signal)
back
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48
Safety Processing Devices
● The safety processing devices contains one or two safety circuit(s) for
processing input signals provided by Detection or/and Control units
and forming safety or/and signaling outputs.
Input
im
Logic
im
Output
● They provide safety solutions for each safety function. The Schneider
Electric range of safety control solutions comprises four product
families:
● dedicated safety modules with one or two safety functions
● configurable controllers managing several safety functions
● safety PLCs used within complex and distributed over SafeEthernet safety
system
● safety monitors and interfaces dedicated to the AS-Interface system,
allowing use of a single medium for control and safety
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Programmable Safety PLC
● The XPS-MF range of Safety PLCs and I/O are Programmable Electronic
Systems (PES) that can be interfaced to safety and non-safety devices to carry
out safety or non-safety related tasks for machinery and equipment
● XPS-MF safety PLCs and Distributed I/O modules are tested and certified by
TÜV for functional safety in accordance to CE and standards:
● IEC 61508 up to SIL 3,
● EN 954-1 up to category 4
● SafeEthernet protocol over Ethernet is certified for safety-related
communication between XPS-MF products
● XPSMFWIN is the project management software used to:
● Configure the safety PLCs,
● Develop the user applications using FBD and SFC languages (IEC 61131-3),
● Carry out on-line tests and diagnostics…
back
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Safety Controllers
● XPS-MP – safety controller module with 15 preprogrammed (only 2 independent
fncts can be chosen) safety functions provide a solution for the majority of safety
applications up to category 4 conforming to the standard EN 954-1/ISO 13849-1
● 6 safety outputs (3 N/O per function)
● 3 solid-state outputs (for signaling to the process PLC)
● XPS-MC – configurable safety controller designed to provide a safety solution
with conformity up to category 4 of standard EN 954-1/ISO 13849-1 and up to
SIL3 requirement of standard IEC 61508
● Safety inputs: 16 or 32
● Safety outputs: 6 solid-state + 2 x 2 relay outputs (4 relay outputs with guided
contacts)
● NON-safety communication via: CANopen, Profibus and Modbus
● XPSMCWIN configuration software for XPS-MC
● Free of charge “Service version” is available for customers
back
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Safety Modules
● Safety Modules – designed to provide a safety solution for the majority
of safety applications. Each safety module performs one or few
preprogrammed safety functions (emergency stop, switch, light curtains,
two-hand control station, etc. monitoring)
● Modules enclosed into housings of width:
● 22,5 mm
● 45 mm
● 90 mm
–
–
–
2 to 3 safety outputs + 1 to 2 additional outputs
3 to 6 safety outputs + 2 to 5 additional outputs
6 to 8 safety outputs + 2 to 6 additional outputs
● Up to the Category 4 max
● depends on the structure and other products used in the solution
back
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AS-i Safety@Work Concept
SAFETY AT WORK
● The Actuator/Sensor Interface or AS-Interface is the only worldwide
standardized bit-oriented fieldbus:
● Power supply, standard data and safety-oriented data transfers on the same
2-wire yellow cable
● The AS-i Safety at Work system can be used to create safety functions up
to Category 4
● AS-interface "Safety at Work" allows direct safety components
connection on the cable:
● Emergency stops
● Limit switches
● Light curtains
● Contact less sensors, etc.
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AS-i Cabling - Maximum security
● AS-i significantly improves machine’s reliability, availability and safety:
● Cabling errors are eliminated:
● A rubberized 2-wire cable (2 x 1.5 mm2)
● The profile section prevents stations being
connected with incorrect polarity
● Risk of electrical connection failure greatly reduced
● High immunity to electromagnetic interference (EMC)
● The machine’s safety function is fully integrated with AS-Interface Safety at Work.
● Connecting modules:
● Contact blades penetrate the rubber jacket and make contact with the two wires
● Removing blades from cable causes no problems - cable is “self-healing”.
● holes made in the rubber jacket of the cable close themselves and revert to the
type of protection IP67
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AS-i Modules
● This diagram illustrates an active AS-i module for four connections
back
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Emergency stop & Emergency switching off
● the emergency stop device is part of the emergency stop function
system of the machine
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Emergency stop & Emergency switching off
Machinery
EN/IEC 60204-1
Safety of machinery
EN/ISO 13850
Emergency Stop Equipment
TRIGGER
Emergency Switching Off
Eliminate the risk of
electrical shock by switching
off the electrical supply
Schneider Electric - Division - Name – Date
Emergency Stop
Eliminate the risk induced
by the machine operation
- Safety risk assessment 57
Emergency stop & Emergency switching off
● What is an emergency stop operation
● Is « an emergency operation intended to stop a process or a movement
that has become hazardous »
 is part of the emergency stop function system of the machine
● What is an emergency switching off operation
● Is « an emergency operation intended to switch off the supply of
electrical energy to all or part of an installation where a risk of electric
shock or another risk of electrical origin is involved »
 is directly linked to risk of electrical origin, related to the machine or not
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Trigger action & non trigger action
●What is a « Trigger action » product
● When the operator is pushing the mushroom head (actuator), the head is
translating to a position where, even if the action on the actuator is
discontinued, the mechanism will continue automatically its translation,
switch the associated contacts and generate the emergency stop command
+ the latching-in of the device.
 as soon as the NC contact starts to become open, the product will latch in the open
position even if you stop to push on the head, or pull the cable.
●What is a « non-trigger action » product
● When the operator is pushing on the mushroom head (actuator) up to the
mechanical stop (over travel), switch the associated contacts and
automatically latch-in.
 when the contact is open and the head is not in its « latching » position, the fact to stop to
push on the head or pull on the cable will close the NC contact again. it is consequently
necessary to push on the head up to its latching point to guarantee and maintain the
opening status of the NC contact.
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Zoom on solutions
Building
Machinery
Emergency
Switching off
Emergency Stop
function
Emergency
Switching off
or
● In Machinery it is obligatory to use
an Emergency Stop with Trigger
function and circular yellow legend
function
=
TRIGGER or
Non-TRIGGER
+
EMERGENCY
SWITCHING OFF
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● However, in Building sector there are
no restrictions on use of the trigger or
non-trigger E-stops
TRIGGER
+
EMERGENCY
STOP
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Emergency Stop Trip-wire
● An e-stop trip wire switch is designed to be
triggered by a single human action when a
normal e-stop function cannot be used
● This applies to:
● Long installations
● Situations where operations are necessary
around the machine
● It is used to transmit a stop command:
Three essential principles:
● Positive operation
● Latching
● Resetting
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● At any point in the work zone
● Regardless of the direction in which the wire is
activated
● These components conform with standard
EN/ISO 13850:2006
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XY2 CH
● Simple to install
Direct mounting of cable
with integral tensioner
Mechanical indication
of the cable tension
Only 2 screws to
attach the cover
● Simple to use
Visual indication of
safety contact
ON
OFF
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24V
48V
130V
230V
Option: Yellow beacon
with incandescent bulb
Low operating force
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XY2 CE
● Simple to install
Anchor point
to the left
Reset device
Anchor point to
the right
Optional window
for cable tension
indication
Polychloroprene
or silicon (for low
temperatures) bellows
Optional indicator light
with incorporated
incandescent bulb to
show state of contacts
back
Schneider Electric - Division - Name – Date
63
Two-hand Control Station
● It requires simultaneous operation by both hands in
order to start and maintain operation of a machine.
It therefore provides protection exclusively for the person operating it.
● The control station can be mounted:
● directly on the machine housing
● on a pedestal, enabling 3 directional adjustment:
●height
●rake
●skew
● Two-hand control station can be operated differently
back
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64
Enabling Switch
● Enabling switches, allow authorised personnel to carry out
maintenance, adjustment or programming operations within hazardous
zones of machines, provided certain conditions are met
● Operating principle - The three possible states are:
● position 0: contact open
(control operator at rest)
● position 1: contact closed
(control operator depressed to
normal enabling position)
● position 2: contact open (control
operator fully depressed)
back
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65
Foot Switch
● Foot switches are an ideal solution for providing start and stop
instructions for many types of industrial machines, running in various
operating modes
● Additional protection and safety possibilities:
● The cover avoids the risk of accidental starting
resulting from a human action or falling object
●Positive action is required on the toe plate 1 before
the pedal 2 can be depressed to start the machine
● Can be mounted directly on the baseplate of the
pedestal XY2 for two-hand control stations
back
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Switch Disconnectors
● Mini-Vario and Vario rotary switch
disconnectors from 12 to 175A
● Used for equipment isolation from electrical
supply and disconnection (interrupt current
running through equipment)
● Can be safely used for «on-load» making and
braking of circuits
● Pad-lockable handle in the Open position
● They does not include any protection
mechanism
● May be used as an Emergency Stop button
(with yellow cover and red handle)
back
Schneider Electric - Division - Name – Date
67
Standards
How to obtain CE marking?!
Directives and Standards
●European Directives are mandatory
● must be translated locally and applied within two years from publication;
● define the "essential requirements", e.g. protection of health and safety
requirements, that product must meet before placed on the European market
● Standards are not mandatory,
● unless they are mentioned in a legislative text on the country level
● The European standards bodies are mandated to draw up the technical
specifications (Harmonized Standards) meeting the requirements of the
Directives
●Comply with the Harmonized Standards is the
simplest way to comply with the Machinery Directive
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69
Standardization Institutes
IEC (electrical standards)
ISO (other standards: mechanical parts...)
CEN (mechanical standards)
CENELEC (electrical standards)
CSA
ANSI
UL
SIS
BS
NF DIN
UNE
CEI
GOST
JIS
OSHA
SAA
(PCB making machines)
ISO: International Organization for Standardization
IEC: International Electrotechnical Commission
CEN: Comité Européen de Normalisation
CENELEC: Comité Européen de Normalisation Electrotechnique
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70
Standardization Bodies
● All countries use IEC and ISO standards or adapt them locally.
● All the main institutes work jointly with other international organizations.
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European Standard’s Subordination
EN 1088
Locking devices
EN 693
hydraulic Presses
EN 953
Fixed and mobile protectors
EN 692
Mechanical presses
EN 60 204-1
Machines electrical
equipment
EN 954-1 = ISO 13849-1:1999
 EN ISO 13849
Safety of machinery
Safety-related part of ctrl sys
EN 294 and 999
Safety distances
A basic std
EN/ISO 13850:2006
Emergency
Stop equipment
EN 574
Bi-manual
command devices
EN 1050 = EN/ISO 14121
Risk assessment
B1 specific safety aspect
B2 safety devices
EN ISO 12100
Fundamental notions,
Design main principles
C specific class of machines
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72
European Machinery Directive 98/37/EC
● European Machinery Directive, an early example of the “New Approach” to
technical harmonisation and standardisation for products, relies on:
 mandatory essential health and safety requirements (which must be met before
machinery is placed on the market)
 voluntary harmonised standards drawn up by the European Committees for
Standardisation (CEN) and Electro-technical Standardisation (Cenelec)
 conformity assessment procedures tailored to the type and level of risks
associated with machinery and,
 the CE marking, affixed by manufacturers to signify compliance with all
relevant directives. Machinery bearing this marking may circulate freely within
the European Economic Area
● A new version of the Machinery Directive 2006/42/EC will be effective in
November 2009
● At the moment both versions are valid
back
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73
Basic concepts
● According to the requirements
of standard EN/ISO 12100-1,
the machine designer’s job is to
reduce all risks to a value lower
than the acceptable risk
● It gives guidelines for the selection
and installation of devices which
can be used to protect persons and identifies those measures that are
implemented by the machine designer and those dependent on its user
● This standard recognises two sources of hazardous phenomena:
● moving parts of machines
● moving tools and/or workpieces
back
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+info
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Risk Assessment Principles
● Machines are sources of potential risk and
the Machinery Directive requires a risk
assessment to ensure that any potential risk is
reduced to less than the acceptable risk
● Risk assessment consists of a series of logic
steps which make it possible to systematically
analyse and evaluate machinery-related risks
● Risk assessment steps:
● Identification of the potential hazard
● Risk estimation
● Risk evaluation
●EN/ISO 13849-1 => Performance Level (PL)
●EN/IEC 62061 => Safety Integrity Level (SIL)
● Risk reduction
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back
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Risk Evaluation
● On the basis of the risk assessment, the designer has to define the
safety related control system. To achieve that, the designer will chose
one of the two standards appropriate to the application:
● either standard EN/ISO 13849-1, which defines performance levels (PL)
● or standard EN/IEC 62061, which defines safety integrity levels (SIL)
● The table below gives relations between these two definitions
-
● To select the applicable standard, a common table in both standards
gives indications:
d
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(1) For designated architectures only
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Remark: Change of Standards
● The qualitative approach of the EN 954-1 is no longer sufficient for modern
controls based on new technologies (Electronic and Programmable Electronic
systems):
● insufficient requirements for programmable products,
● The reliability of the components is not taken into account,
● too deterministic orientation (designated architectures).
● Standard EN ISO 13849-1 will totally replace the EN 954-1 in November 2009,
and will upgrade the qualitative approach by the new quantitative (probabilistic)
approach and is consistent with safety standards in general.
● At the moment both standards EN 954-1 and EN/ISO 13849-1 are valid
● For complex machines using programmable systems for safety-related control,
the sector specific standard EN/IEC 62061 has to be considered
● EN/IEC 62061 based on EN/IEC 61508
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77
Standard EN/IEC 62061
● Specific to the machine sector within the framework of EN/IEC 61508:
● gives rules for the integration of safety-related electrical, electronic and
electronic programmable control systems (SRECS)
● does not specify the operating requirements of non-electrical control
components in machine (ex.: hydraulic, pneumatic)
● The probability of failure associated to the required SIL (Safety Integrity
Level) depends on the frequency of usage of the safety function to be
performed
Safety of Machinery
application
EN/IEC 62061
Schneider Electric - Division - Name – Date
back
78
Standard EN/ISO 13849-1
● The Standard gives safety requirements for the design and integration
of safety-related parts of control systems, including software design.
● The Risk Graph helps to determine the required PL (Performance
Level) of each safety function
● S - Severity of injury
>S1 Slight injury
>S2 Serious or permanent injury or death
● F - Frequency and / or exposure to a hazard
>F1 Seldom to less often and / or short time
>F2 Frequent to continuous and / or long time
● P - Possibility of avoiding the hazard or limiting the harm
>P1 Possible under specific conditions
>P2 Scarcely possible
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79
Relationship Between Different Criteria
● Relationship between Categories, DCavg, MTTFd and PL
*In several application the realisation
of performance level c by category 1
may not be sufficient. In this case a
higher category e.g. 2 or 3 should
be chosen.
back
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80
Electrical Equipment of
Machines
● Standard EN/IEC 60204-1 completes the safety standards by giving
setting-up rules for each component of a machine’s electrical functions.
It specifies, amongst other things:
● the type of connection terminals and disconnection and breaking devices,
● the type of electric shock protection,
● the type of control circuits,
● the type of conductors and wiring rules,
● the type of motor protection.
back
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81
Summary: 6 steps to get
the “passport”
● Schneider Electric wants to support the customers of PREVENTA safety
products in order to achieve easily the certification of their machines.
● There are 6 steps in the process of certification and CE marking of
machines:
1.
2.
3.
4.
5.
6.
Applying all relevant directives and standards
Complying to the essential health and safety requirements
Draw up the technical documentation
CE-Type-examination (if applicable proceed with the conformity examination)
Draw up the Declaration of Conformity
Affix the CE marking
● Anyway for all machines listed in annex IV the customer needs a
document from the notified body before affixing the CE mark on the
machine
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82
Recommendations
● Today there are 575 harmonised standards under the machinery
directive, and out of that we find about 350 standards for
machines. Nevertheless there are only a few harmonised
standards for the machines listed in annex IV.
● In order to ensure the adequate consideration of all applicable
standards it is advisable to have made a CE Type-Examination.
● Specially in all cases where an CE Type-Examination is made, the
Notified Body should be involved from the beginning of the project
in order to detect discrepancies as early as possible during the
development phase and also in order to achieve the certification
as soon as possible at the end of the project.
back
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83
Safety Principles
Focus on basic safety concept
Positive Opening Operation
● The achievement of contact separation as the direct result of a specified
movement of the switch actuator through non-resilient members
● Safety switches employ a rigid mechanical link from the actuator to
open Normally Closed contacts. The normal operation of the switch will
force apart contacts, even those that are welded shut. For more
information see ISO14119 and IEC 60947-5-1
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85
Operation in Negative Mode
● In case of welded contacts or broken spring contacts stays in the closed
position, which may result on the safety of machine and personnel
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86
Combined Mode
● To clear faults due to positive mode, use combined mode
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Mechanically Linked Electrical Contacts
● Mechanical guiding (forced
guiding) makes it impossible to
close the normally closed and
normally open contacts
simultaneously
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● If a failure occurs: contact A welded;
then contact B stays open.
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Locking and Interlocking Devices
Monitoring
device
Danger
zone
Normal
approach
Access time =
Time to cover distance S
S
Interlocking
devices
Interlocking
devices with
locking function
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● Stops the machine and allow immediate access
as soon as the access request is detected
● XCS-MP, XCS-M, XCS-TA, XCS-PA, etc.
Stopping time < access time
● Allow access to the machine only after
it’s complete stop
● XCS-TE, XCS-E, XCS-B /C, etc.
Stopping time > access time
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Mirror Contacts
● An electrical auxiliary contact mechanically linked to the power poles is
an N/C auxiliary contact which can never be closed at the same time as
the power poles
● If one of the power pole contacts
becomes welded, the mechanical
link prevents the N/C auxiliary
contact from closing when the coil
is de-energised
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90
Redundancy and Self-monitoring
Redundancy
Consists of compensating for the
failure of one component by
correct operation of another, based
on the assumption that
both will not fail simultaneously
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Self-monitoring
Consists of automatically checking
the operation of each of the
components which change state at
each cycle
91
Redundancy + Self-monitoring
Redundancy
Self-monitoring
+
= the risk of not operating safely is hardly reduced down
to an acceptable level compared to the consequences
An initial fault in the safety circuit is detected before a second fault
occurs (next cycle inhibited)
back
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92
T hanks
for your attention
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