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MLC 520S
Safety Light Curtains
EN 2019/03/11 - 50137900
We reserve the right to make technical changes
S A F E I M P L E M E N T A T I O N A N D O P E R A T I O N
O r i g i n a l o p e r a t i n g i n s t r u c t i o n s
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© 2019
Leuze electronic GmbH & Co. KG
In der Braike 1
D-73277 Owen / Germany
Phone: +49 7021 573-0
Fax: +49 7021 573-199
http://www.leuze.com
info@leuze.com
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Table of contents
Table of contents
1 About this document ............................................................................................5
1.1 Used symbols and signal words .............................................................................................5
1.2 Checklists................................................................................................................................ 6
2 Safety .....................................................................................................................7
2.1 Intended use and foreseeable misuse.................................................................................... 7
2.1.1 Intended use........................................................................................................................ 7
2.1.2 Foreseeable misuse ............................................................................................................8
2.2 Necessary competencies........................................................................................................ 8
2.3 Responsibility for safety.......................................................................................................... 9
2.4 Disclaimer ............................................................................................................................... 9
3 Device description ..............................................................................................10
3.1 Device overview of the MLC family....................................................................................... 10
3.2 Connection technology .........................................................................................................10
3.3 Cascading............................................................................................................................. 11
3.4 Display elements .................................................................................................................. 12
3.4.1 Operation indicators on the MLC520S transmitter/receiver .............................................12
4 Functions.............................................................................................................14
4.1 Start/restart interlock RES ....................................................................................................14
4.2 EDM contactor monitoring ....................................................................................................15
5 Applications ........................................................................................................16
5.1 Point of operation guarding................................................................................................... 16
6 Mounting..............................................................................................................17
6.1 Arrangement of transmitter and receiver ..............................................................................17
6.1.1 Calculation of safety distanceS ........................................................................................17
6.1.2
6.1.3 Minimum distance to reflective surfaces ...........................................................................21
6.1.4 Preventing mutual interference between adjacent devices ...............................................22
6.2 Mounting the safety sensor................................................................................................... 23
6.2.1 Suitable mounting locations ..............................................................................................23
6.2.2 Mounting with O-shaped mounting brackets .....................................................................24
6.2.3 Mounting with C-shaped mounting brackets .....................................................................25
6.2.4 Mounting with L-shaped mounting brackets......................................................................27
6.2.5 Mounting with L- and C-shaped mounting brackets ..........................................................29
6.3 Mounting accessories ........................................................................................................... 30
6.3.1 Deflecting mirror for multiple-side guarding....................................................................... 30
6.3.2 Mounting cascading ..........................................................................................................30
Calculation of safety distance if protective fields act orthogonally to the approach direction.. 18
7 Electrical connection..........................................................................................33
7.1 Pin assignment transmitter and receiver .............................................................................. 33
7.1.1 MLC520S transmitter .......................................................................................................33
7.1.2 MLC520S receiver............................................................................................................ 34
8 Starting up the device ........................................................................................35
8.1 Switching on ......................................................................................................................... 35
8.2 Aligning the sensor ...............................................................................................................35
8.3 Minimum distance for cascade system................................................................................. 37
8.4 Selection of RESTART mode and operation ........................................................................37
8.5 Unlocking start/restart interlock ............................................................................................ 39
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Table of contents
9 Testing .................................................................................................................40
9.1 Before commissioning and following modifications .............................................................. 40
9.1.1 Checklist for integrator – to be performed prior to commissioning and following modifica-
tions...................................................................................................................................40
9.2 To be performed periodically by competent persons............................................................ 42
9.3 Periodically by the operator ..................................................................................................42
9.3.1 Checklist – periodically by the operator............................................................................. 42
10 Maintenance ........................................................................................................44
11 Troubleshooting..................................................................................................45
11.1 What to do in case of failure? ...............................................................................................45
11.2 Operating indicator of the LEDs............................................................................................ 45
12 Disposing.............................................................................................................48
13 Service and support ...........................................................................................49
14 Technical data .....................................................................................................50
14.1 General specifications .......................................................................................................... 50
14.2 Dimensions, weight, response time ...................................................................................... 52
14.3 Dimensioned drawings: Accessories .................................................................................... 54
15 Order guide and accessories.............................................................................57
16 EU/EC Declaration of Conformity ......................................................................60
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1 About this document
1.1 Used symbols and signal words
Tab.1.1: Warning symbols and signal words
Symbol indicating dangers to persons
Symbol indicating possible property damage
NOTE Signal word for property damage
Indicates dangers that may result in property damage if the measures for danger avoidance are not followed.
CAUTION Signal word for minor injuries
Indicates dangers that may result in minor injury if the measures for danger
avoidance are not followed.
WARNING Signal word for serious injury
Indicates dangers that may result in severe or fatal injury if the measures for
danger avoidance are not followed.
About this document
DANGER Signal word for life-threatening danger
Indicates dangers with which serious or fatal injury is imminent if the measures
for danger avoidance are not followed.
Tab.1.2: Other symbols
Symbol for tips
Text passages with this symbol provide you with further information.
Symbol for action steps
Text passages with this symbol instruct you to perform actions.
Symbol for action results
Text passages with this symbol describe the result of the preceding action.
Tab.1.3: Terms and abbreviations
Response time The response time of the protective device is the maximum time between the
occurrence of the event that results in activation of the safety sensor and the
provision of the switching signal at the interface of the protective device (e.g.,
OFF state of the OSSD pair).
AOPD Active Optoelectronic Protective Device
(Active Optoelectronic Protective Device)
ESPE Electro-sensitive protective equipment
EDM Contactor monitoring
(External Device Monitoring)
LED LED, display element in transmitter and receiver
MLC Brief description of the safety sensor, consisting of transmitter and receiver
MTTF
d
Mean time to dangerous failure
(Mean Time To dangerous Failure)
OSSD Safety-related switching output
(Output Signal Switching Device)
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About this document
PFH
d
PL Performance Level
RES Start/restart interlock
Scan Consecutive scans of the protective field from the first to the last beam
Safety sensor System consisting of transmitter and receiver
SIL Safety Integrity Level
State ON: device intact, OSSD switched on
1.2 Checklists
The checklists (see chapter 9 "Testing") serve as a reference for the machine manufacturer or supplier.
They replace neither testing of the complete machine or system prior to initial commissioning nor their periodic testing by a qualified person (see chapter 2.2 "Necessary competencies"). The checklists contain minimum testing requirements. Depending on the application, other tests may be necessary.
Probability of a dangerous failure per hour
(Probability of dangerous Failure per Hour)
(Start/REStart interlock)
OFF: device intact, OSSD switched off
Locking: device, connection or control / operation faulty, OSSD switched off
(lock-out)
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2 Safety
For mounting, operating and testing, this document as well as all applicable national and international standards, regulations, rules and directives must be observed. Relevant and supplied documents must be observed, printed out and handed to affected persons.
Ä Before working with the safety sensor, completely read and observe the documents applicable to your
task.
In particular, the following national and international legal regulations apply for the commissioning, technical inspections and work with safety sensors:
• Directive 2006/42/EC
• Directive 2014/35/EU
• Directive 2014/30/EU
• Directive 89/655/EEC supplemented by directive 95/63EC
• OSHA 1910 Subpart O
• Safety regulations
• Accident-prevention regulations and safety rules
• Ordinance on Industrial Safety and Health and employment protection act
• Product Safety Law (ProdSG and 9. ProdSV)
Safety
NOTICE
For safety-related information you may also contact local authorities (e.g., industrial inspectorate, employer's liability insurance association, labor inspectorate, occupational safety and
health authority).
2.1 Intended use and foreseeable misuse
WARNING
A running machine may result in serious injury!
Ä Make certain that the safety sensor is correctly connected and that the protective function of
the protective device is ensured.
Ä Make certain that, during all conversions, maintenance work and inspections, the system is
securely shut down and protected against being restarted.
2.1.1
Intended use
• The safety sensor may only be used after it has been selected in accordance with the respectively applicable instructions and relevant standards, rules and regulations regarding labor protection and safety
at work, and after it has been installed on the machine, connected, commissioned, and checked by a
competent person (see chapter 2.2 "Necessary competencies"). The devices are designed for indoor
use only.
• When selecting the safety sensor it must be ensured that its safety-related capability meets or exceeds
the required performance level PLr ascertained in the risk assessment (see chapter 14.1 "General
specifications").
• The safety sensor protects persons or body parts at points of operation, danger zones or access points
of machines and systems.
• With the access guarding function, the safety sensor detects persons only when they enter the danger
zone but cannot tell whether there are any persons inside the danger zone. For this reason, a start/
restart interlock or a suitable stepping behind protection in the safety chain is essential in this case.
• Maximum permissible approach speeds (see ISO13855):
• 1.6m/s for access guarding
• 2.0m/s for guards of points of operation
• The construction of the safety sensor must not be altered. When manipulating the safety sensor, the
protective function is no longer guaranteed. Manipulating the safety sensor also voids all warranty
claims against the manufacturer of the safety sensor.
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Safety
• The improper repair of the protective device may result in loss of the protective function. Make no repairs to the device components.
• The safety sensor must be inspected regularly by a competent person to ensure proper integration and
mounting (see chapter 2.2 "Necessary competencies").
• The safety sensor must be exchanged after a maximum of 20 years. Repairs or the exchange of wear
parts do not extend the mission time.
2.1.2
Foreseeable misuse
Any use other than that defined under the “Approved purpose” or which goes beyond that use is considered improper use.
In principle, the safety sensor is not suitable as a protective device for use in the following cases:
• Danger posed by ejected objects or the spraying of hot or hazardous liquids from within the danger
zone
• Applications in explosive or easily flammable atmospheres
2.2 Necessary competencies
The safety sensor may only be configured, installed, connected, commissioned, serviced and tested in its
respective application by persons who are suitably qualified for the given task. General prerequisites for
suitably qualified persons:
• They have a suitable technical education.
• They are familiar with the relevant parts of the operating instructions for the safety sensor and the operating instructions for the machine.
Task-specific minimum requirements for competent persons:
Configuration
Specialist knowledge and experience in the selection and use of protective devices on machines as well as
the application of technical rules and the locally valid regulations on labor protection, safety at work and
safety technology.
Specialist knowledge in programming safety-related controls SRASW acc. to ISO13849-1.
Mounting
Specialist knowledge and experience needed for the safe and correct installation and alignment of the
safety sensor with regard to the respective machine.
Electrical installation
Specialist knowledge and experience needed for the safe and correct electrical connection as well as safe
integration of the safety sensor in the safety-related control system.
Operation and maintenance
Specialist knowledge and experience needed for the regular inspection and cleaning of the safety sensor –
following instruction by the person responsible.
Servicing
Specialist knowledge and experience in the mounting, electrical installation and the operation and maintenance of the safety sensor in accordance with the requirements listed above.
Commissioning and testing
• Experience and specialist knowledge in the rules and regulations of labor protection, safety at work and
safety technology that are necessary for being able to assess the safety of the machine and the use of
the safety sensor, including experience with and knowledge of the measuring equipment necessary for
performing this work.
• In addition, a task related to the subject matter is performed in a timely manner and knowledge is kept
up to date through continuous further training ‑ Competent person in terms of the German Betriebssicherheitsverordnung (Ordinance on Industrial Safety and Health) or other national legal regulations.
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2.3 Responsibility for safety
Manufacturer and operator must ensure that the machine and implemented safety sensor function properly
and that all affected persons are adequately informed and trained.
The type and content of all imparted information must not lead to unsafe actions by users.
The manufacturer of the machine is responsible for:
• Safe machine construction and information on any residual risks
• Safe implementation of the safety sensor, verified by the initial test performed by a competent person
(see chapter 2.2 "Necessary competencies")
• Imparting all relevant information to the operating company
• Adhering to all regulations and directives for the safe commissioning of the machine
The operator of the machine is responsible for:
• Instructing the operator
• Maintaining the safe operation of the machine
• Adhering to all regulations and directives for labor protection and safety at work
• Periodic testing by a competent person (see chapter 2.2 "Necessary competencies")
2.4 Disclaimer
The liability of Leuze electronic GmbH + Co. KG is to be excluded in the following cases:
• Safety sensor is not used as intended.
• Safety notices are not adhered to.
• Reasonably foreseeable misuse is not taken into account.
• Mounting and electrical connection are not properly performed.
• Proper function is not tested (see chapter 9 "Testing").
• Changes (e.g., constructional) are made to the safety sensor.
Safety
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3 Device description
The safety sensors from the MLC 500 series are active opto-electronic protective devices. They satisfy the
following standards:
Type in accordance with ENIEC61496 4
Category in accordance with ENISO13849 4
Performance Level (PL) in accordance with ENISO13849-1:2015 e
Device description
MLC 500
Safety Integrity Level (SIL) in accordance with IEC61508 and SILCL in accordance with ENIEC62061
The safety sensor consists of a transmitter and a receiver (see chapter 3.1 "Device overview of the MLC
family"). It is protected against overvoltage and overcurrent acc. to IEC60204-1 (protection class3). The
safety sensor is not dangerously influenced by ambient light (e.g., welding sparks, warning lights).
3.1 Device overview of the MLC family
The series consists of a transmitter and the corresponding receiver. An overview of the characteristic features is given in the following table.
Tab.3.1: Device models in the series with specific features and functions
OSSDs (2x) ■
LED indicator ■ ■
Automatic start/restart ■
RES ■
EDM ■
Protective field properties
The beam distance and the number of beams are dependent on the resolution and protective field height.
3
Transmitter Receiver
MLC 520S MLC 520S
Device synchronization
The synchronization of receiver and transmitter for creating a functioning protective field is done optically,
i.e. without cables, via one specially coded synchronization beam. The synchronization beam is the beam
closest to the cable connection. A cycle (i.e. a pass from the first to the last beam) is called a scan.
3.2 Connection technology
The transmitter and receiver feature cables with M12 connectors as an interface to the machine control
with the following number of pins:
Device model Device type Device plug
MLC 520S Transmitter/receiver 5-pin
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3.3 Cascading
To implement linked protective fields, up to three MLC safety light curtains can be cascaded one after the
other.
Adjacent protective fields, e.g., for stepping behind protection, can thereby be implemented without any additional expense for control and connection. The master system performs all necessary processor tasks,
provides indicators and the receiver-side interfaces to the machine and command devices.
Devices with different resolutions can be combined.
To enable connection in cascade systems, cascade cables are available as accessories.
With mounting brackets, an L- or U-shaped fixed connection can be created (see chapter 15 "Order guide
and accessories").
Mounting instructions see chapter 6.3.2 "Mounting cascading".
Device description
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3.4 Display elements
1
2
7
8
9 10
6
1
2
3
4
5
6
The display elements of the safety sensors simplify start-up and fault analysis.
Device description
3.4.1
Operation indicators on the MLC520S transmitter/receiver
Located on both the transmitter and receiver are six LEDs for displaying the operating state:
1 LED1
2 LED2
3 LED EDM/3
4 LED RES
5 OSSD LED
6 PWR LED
7 LED3
8 LED TX
9 Transmitter
10 Receiver
Fig.3.1: Indicators on the MLC 520S transmitter/receiver
Tab.3.2: Meaning of the LEDs on the transmitter
Operating
LED indicator Description
mode
NORMAL
OPERATION
LOCKOUT
ERROR
Normal operation
Internal error
Optical scan error
Cascade communication error
Reset error
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Tab.3.3: Meaning of the LEDs on the receiver
Device description
Operating
LED indicator Description
mode
ALIGNMENT Alignment indicator
NORMAL
OPERATION
NORMAL
Normal operation – manual
reset
Normal operation
OPERATION
Safety status
LOCKOUT
ERROR
EDM function enabled
Internal error
Optical scanning error
EDM error
Cascade communication er-
ror
Restart function error
Safety-related switching
outputs error
Supply error
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4 Functions
An overview of features and functions of the safety sensor can be found in chapter “Device description” (see chapter 3.1 "Device overview of the MLC family").
Overview of functions
• Start/restart interlock (RES)
• EDM
4.1 Start/restart interlock RES
After accessing the protective field, the start/restart interlock ensures that the safety sensor remains in the
OFF state after the protective field has been cleared. It prevents automatic release of the safety circuits
and automatic start-up of the system, e.g. if the protective field is again clear or if an interruption in the voltage supply is restored.
NOTICE
For access guarding, the start/restart interlock function is mandatory. The protective device may
only be operated without start/restart interlock in certain exceptional cases and under certain
conditions acc. to ISO12100.
WARNING
Functions
Deactivation of the start/restart interlock may result in serious injury!
Ä Implement the start/restart interlock on the machine or in a downstream safety circuit.
Using start/restart interlock
Ä Wire the MLC 520S receiver appropriately for the desired function (see chapter 7 "Electrical connec-
tion").
The start/restart interlock function is activated or deactivated through appropriate wiring
Switching the safety sensor back on after shutting down (OFF state):
Ä Press the reset button (press/release between 0.15s and 4s)
NOTICE
The reset button must be located outside the danger zone in a safe place and give the operator
a good view of the danger zone so that he/she can check whether anyone is located in it (according to IEC62046) before pressing the reset button.
DANGER
Risk of death if start/restart is operated unintentionally!
Ä Ensure that the reset button for unlocking the start/restart interlock cannot be reached from
the danger zone.
Ä Before unlocking the start/restart interlock, make certain that no people are in the danger
zone.
After the reset button has been actuated, the safety sensor switches to the ON state.
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4.2 EDM contactor monitoring
NOTICE
The contactor monitoring of the MLC 520S safety sensors can be activated through appropriate
wiring (see chapter 7 "Electrical connection")!
The “contactor monitoring” function monitors the contactors, relays or valves connected downstream of the
safety sensor. Prerequisite for this are switching elements with positive-guided feedback contacts (normally
closed contacts).
Implement the contactor monitoring function:
• through appropriate wiring of the MLC 520S safety sensors (see chapter 7 "Electrical connection").
• through the external contactor monitoring of the downstream safety relay, (e.g. MSI series from Leuze
electronic)
• or through contactor monitoring of the downstream safety PLC (optional, integrated via a safety bus)
If contactor monitoring is activated (see chapter 7 "Electrical connection"), it operates dynamically, i.e., in
addition to monitoring the closed feedback circuit every time before the OSSDs are switched on, it also
checks whether the release of the feedback circuit opened within 350ms and, after the OSSDs are
switched off, whether it has closed again within 350ms. If this is not the case, the OSSDs return to the
OFF state after being switched on briefly. An error message is displayed (see chapter 11 "Troubleshooting"). The receiver switches to the fault interlock state from which it can only be returned to normal operation by switching the supply voltage off and back on again.
Functions
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5 Applications
The safety sensor only creates square protective fields.
5.1 Point of operation guarding
Point of operation guarding for hand and finger protection is typically the most common application for this
safety sensor. In accordance with ENISO13855, resolutions from 14to40mm make sense here. This
yields the necessary safety distance, among others (see chapter 6.1.1 "Calculation of safety distanceS").
Applications
Fig.5.1: Point of operation guarding protects reaching into the danger zone, e.g. for cartoners or filling systems
Fig.5.2: Point of operation guarding protects reaching into the danger zone, e.g. for a pick&place robot applica-
tion
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6 Mounting
Improper mounting may result in serious injury!
The protective function of the safety sensor is only ensured if appropriately and professionally
mounted for the respective, intended area of application.
Mounting
WARNING
Ä Only allow the safety sensor to be installed by qualified persons (see chapter 2.2 "Neces-
sary competencies").
Ä Maintain the necessary safety distances (see chapter 6.1.1 "Calculation of safety dis-
tanceS").
Ä Make sure that stepping behind, crawling under or stepping over the protective device is reli-
ably ruled out and reaching under, over or around is taken into account in the safety distance, if applicable with additional distanceCRO corresponding to ISO13855.
Ä Take measures to prevent that the safety sensor can be used to gain access to the danger
zone, e.g. by stepping or climbing into it.
Ä Observe the relevant standards, regulations and these instructions.
Ä Clean the transmitter and receiver at regular intervals: environmental conditions (see chap-
ter 14 "Technical data"), care (see chapter 10 "Maintenance").
Ä After mounting, check the safety sensor for proper function.
6.1 Arrangement of transmitter and receiver
Optical protective devices can only perform their protective function if they are mounted with adequate
safety distance. When mounting, all delay times must be taken into account, such as the response times of
the safety sensor and control elements as well as the stopping time of the machine, among others.
The following standards specify calculation formulas:
• IEC61496-2, "Active optoelectronic protective devices": distance of the reflecting surfaces/deflecting
mirrors
• ISO13855, "Safety of machines - The positioning of protective equipment in respect of approach
speeds of parts of the human body": mounting situation and safety distances
NOTICE
In accordance with ISO13855, with a vertical protective field, it is possible to pass under beams
over 300mm or pass over beams under 900mm. If the protective field is horizontal, climbing on
the safety sensor must be prevented through suitable installation or with covers and the like.
6.1.1
Calculation of safety distanceS
General formula for calculating the safety distanceS of an Optoelectronic Protective Device acc. to
ISO13855
S [mm] = Safety distance
K [mm/s] = Approach speed
T [s] = Total time of the delay, sum from (ta+ti+tm)
t
[s] = Response time of the protective device
a
t
[s] = Response time of the safety relay
i
t
[s] = Stopping time of the machine
m
C [mm] = Additional distance to the safety distance
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Mounting
NOTICE
If longer stopping times are determined during regular inspections, an appropriate additional
time must be added to tm.
6.1.2
Calculation of safety distance if protective fields act orthogonally to the approach direction
With vertical protective fields, ISO13855 differentiates between
• SRT: safety distance concerning access through the protective field
• SRO: safety distance concerning access over the protective field
The two values are distinguished by the way additional distanceC is determined:
• CRT: from a calculation formula or as a constant (see chapter 6.1.1 "Calculation of safety distanceS")
• CRO: from the following table “Reaching over the vertical protective field of electro-sensitive protective
equipment (excerpt from ISO13855)”
The larger of the two values SRT and SRO is to be used.
Calculation of safety distanceSRT acc. to ISO13855 when access occurs through the protective
field:
Calculation of safety distanceSRT for point of operation guarding
S
[mm] = Safety distance
RT
K [mm/s] = Approach speed for point of operation guarding with approach reaction and normal approach di-
rection to the protective field (resolution 14to40mm): 2000mm/s or 1600mm/s, when
SRT>500mm
T [s] = Total time of the delay, sum from (ta+ti+tm)
t
[s] = Response time of the protective device
a
t
[s] = Response time of the safety relay
i
t
[s] = Stopping time of the machine
m
C
[mm] = Additional distance for point of operation guarding with approach reaction with resolutions of
RT
14to40mm, d=resolution of protective device CRT=8×(d-14)mm
Calculation of safety distanceSRo acc. to ISO13855 when protective field is accessed from above:
Calculation of safety distanceSRo for point of operation guarding
S
[mm] = Safety distance
RO
K [mm/s] = Approach speed for point of operation guarding with approach reaction and normal approach di-
rection to the protective field (resolution 14to40mm): 2000mm/s or 1600mm/s, when
SRO>500mm
T [s] = Total time of the delay, sum from (ta+ti+tm)
t
[s] = Response time of the protective device
a
t
[s] = Response time of the safety relay
i
t
[s] = Stopping time of the machine
m
C
[mm] = Additional distance in which a body part can move towards the protective device before the pro-
RO
tective device triggers: value (see the following table “Reaching over the vertical protective field
of electro-sensitive protective equipment (excerpt from ISO13855)”).
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a
3
C
RO
KxT
b
1
2
S
RO
1 Safety sensor
2 Danger zone
3 Floor
a Height of the point of operation
b Height of the upper beam of the safety sensor
Mounting
Fig.6.1: Additional distance to the safety distance when reaching over and under
Tab.6.1: Reaching over the vertical protective field of electro-sensitive protective equipment(excerpt from
ISO13855)
Heighta
of the
point of
operation
Heightb of the upper edge of the protective field of the electro-sensitive protective
equipment
900 1000 1100 1200 1300 1400 1600 1800 2000 2200 2400 2600
Additional distanceCRO to the danger zone [mm]
[mm]
2600 0 0 0 0 0 0 0 0 0 0 0 0
2500 400 400 350 300 300 300 300 300 250 150 100 0
2400 550 550 550 500 450 450 400 400 300 250 100 0
2200 800 750 750 700 650 650 600 550 400 250 0 0
2000 950 950 850 850 800 750 700 550 400 0 0 0
1800 1100 1100 950 950 850 800 750 550 0 0 0 0
1600 1150 1150 1100 1000 900 850 750 450 0 0 0 0
1400 1200 1200 1100 1000 900 850 650 0 0 0 0 0
1200 1200 1200 1100 1000 850 800 0 0 0 0 0 0
1000 1200 1150 1050 950 750 700 0 0 0 0 0 0
800 1150 1050 950 800 500 450 0 0 0 0 0 0
600 1050 950 750 550 0 0 0 0 0 0 0 0
400 900 700 0 0 0 0 0 0 0 0 0 0
200 600 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0
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Mounting
Depending on the specified values you can work with the above-mentioned table in three ways:
1. Given are:
• Heighta of the point of operation
• DistanceS of the point of operation from the safety sensor, and additional distanceC
RO
To be determined is the required heightb of the upper beam of the safety sensor and thereby its protective
field height.
Ä Look for the line with the specification of the point of operation height in the left column.
Ä In this line, look for the column with the next highest specification for additional distance CRO.
ð The required height of the upper beam of the safety sensor is up top in the column head.
2. Given are:
• Heighta of the point of operation
• Heightb of the upper beam of the safety sensor
To be determined is the required distance S of the safety sensor to the point of operation and thereby additional distance CRO.
Ä In the column head, look for the column with the next lowest entry for the height of the upper beam of
the safety sensor.
Ä Look for the line with the next highest specification of the point of operation heighta in this column.
ð In the intersection point of the line and the column, you will find additional distanceCRO.
3. Given are:
• DistanceS of the point of operation from the safety sensor, and additional distanceC
RO.
• Heightb of the upper beam of the safety sensor
To be determined is the permitted heighta of the point of operation.
Ä In the column head, look for the column with the next lowest entry for the height of the upper beam of
the safety sensor.
Ä Look for the next lowest value for real additional distance CRO in this column.
ð In this line, go to the left column: here you will find the permitted height of the point of operation.
Ä Now calculate safety distanceS using the general formula acc. to ISO13855 (see chapter 6.1.1 "Cal-
culation of safety distanceS").
ð The larger of the two values SRT and SRO is to be used.
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Mounting
a
b
4°
4°
c
a
900 mm
200 mm
800 mm
300 mm
400 mm
600 mm
500 mm
700 mm
3 m
5 m 10 m
b
131 mm
15 m
20 m
25 m
1100 mm
1000 mm
6.1.3
Minimum distance to reflective surfaces
WARNING
Failure to maintain minimum distances to reflective surfaces may result in serious injury!
Reflective surfaces can indirectly deflect the transmitter beams to the receiver. In this case, interruption of the protective field is not detected.
Ä Determine the minimum distancea (see figure below).
Ä Make certain that all reflective surfaces are the necessary minimum distance away from the
protective field according to IEC61496-2 (see the following diagram “Minimum distance to
reflective surfaces as a function of the protective field width”).
Ä Check that reflective surfaces do not impair the detection capability of the safety sensor be-
fore start-up and at appropriate intervals.
a Required minimum distance to reflective surfaces [mm]
b Protective field width [m]
c Reflective surface
Fig.6.2: Minimum distance to reflective surfaces depending on protective field width
a Required minimum distance to reflective surfaces [mm]
b Protective field width [m]
Fig.6.3: Minimum distance to reflective surfaces as a function of the protective field width
Tab.6.2: Formula for calculating the minimum distance to reflective surfaces
Distance(b) transmitter-receiver Calculation of the minimum distance(a) to reflective sur-
faces
b≤3m a[mm]=131
b>3m a[mm]=tan(2.5°)×1000×b[m]=43.66×b[m]
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Mounting
3
1
4
2
3
1
4
2
6.1.4
Preventing mutual interference between adjacent devices
If a receiver is located in the beam path of an adjacent transmitter, optical crosstalk, and thus erroneous
switching and failure of the protective function, may result.
Fig.6.4: Optical crosstalk between adjacent safety sensors (transmitter1 influences receiver2) due to incorrect
mounting
1 Transmitter1
2 Receiver1
3 Transmitter2
4 Receiver2
NOTICE
Possible impairment of the availability due to systems mounted close to each other!
The transmitter of one system can influence the receiver of the other system.
Ä Prevent optical crosstalk between adjacent devices.
Ä
Mount adjacent devices with a shield between them or install a dividing wall to prevent mutual interference.
Ä Mount the adjacent devices opposite from one another to prevent mutual interference.
Fig.6.5: Opposite mounting
1 Receiver1
2 Transmitter1
3 Transmitter2
4 Receiver2
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6.2 Mounting the safety sensor
Proceed as follows:
• Select the type of fastening:
• O-shaped mounting bracket (see chapter 6.2.2 "Mounting with O-shaped mounting brackets")
• C-shaped mounting bracket (see chapter 6.2.3 "Mounting with C-shaped mounting brackets")
• L-shaped mounting bracket (see chapter 6.2.4 "Mounting with L-shaped mounting brackets")
• Mounting with L- and C-shaped mounting brackets (see chapter 6.2.5 "Mounting with L- and Cshaped mounting brackets")
• Have a suitable tool at hand and mount the safety sensor in accordance with the notices regarding the
mounting locations (see chapter 6.2.1 "Suitable mounting locations").
• If possible, affix safety notice stickers on the mounted safety sensor or device column (included in delivery contents).
After mounting, you can electrically connect (see chapter 7 "Electrical connection"), start up, align (see
chapter 8 "Starting up the device"), and test (see chapter 9.1 "Before commissioning and following modifications") the safety sensor.
Mounting
6.2.1
Suitable mounting locations
Area of application: Mounting
Tester: Technician who mounts the safety sensor
Tab.6.3: Checklist for mounting preparations
Check: Yes No
Do the protective field height and dimensions satisfy the requirements of ISO13855?
Is the safety distance to the point of operation maintained (see chapter 6.1.1 "Calculation
of safety distanceS")?
Is the minimum distance to reflective surfaces maintained (see chapter 6.1.3 "Minimum
distance to reflective surfaces")?
Is it impossible for safety sensors that are mounted next to one another to mutually interfere with one another (see chapter 6.1.4 "Preventing mutual interference between adjacent
devices")?
Can the point of operation or the danger zone only be accessed through the protective
field?
Has bypassing the protective field by crawling under, reaching over, or jumping over been
prevented or has corresponding additional distanceCRO in accordance with ISO13855
been observed?
Is stepping behind the protective device prevented or is mechanical protection available?
Do the transmitter and receiver connections point in the same direction?
Can the transmitter and receiver be fastened in such a way that they cannot be moved
and turned?
Is the safety sensor accessible for testing and replacing?
Is it impossible to actuate the reset button from within the danger zone?
Can the entire danger zone be seen from the installation site of the reset button?
Can reflection caused by the installation site be ruled out?
NOTICE
If you answer one of the items on the checklist above with no, the mounting location must be
changed.
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Mounting
6.2.2
Mounting with O-shaped mounting brackets
Ä Drill two bore holes in the holder with a center distance of Lø according to the table.
Model Lø [mm]
150 162.20
210 222.10
270 282.00
300 312.00
330 341.90
360 371.90
390 401.70
420 431.70
450 461.70
480 491.60
510 621.60
540 551.50
570 581.50
600 611.50
Ä Mount the two O-shaped mounting brackets in the correct position. In doing so, do not completely
tighten the M4 screws.
Ä Place the device between the two brackets. Snap the ends of the light curtain in the mounting brackets.
Ä Fully tighten the screws with a maximum tightening torque of 1.2Nm.
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Mounting
L
2
2
1
1
1 O-shaped mounting bracket
6.2.3
2 M4 screw, tightening torque: 1.2Nm max.
Fig.6.6: Mounting with O-shaped mounting brackets
Mounting with C-shaped mounting brackets
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Mounting
1/4 L
1/4 L
1
3
2
Ä Mount the C-shaped mounting brackets with the M4 screws at the correct distance. The recommended
distance for the C-shaped mounting brackets depends on the device; it is approximately 1/4 the length
of the light curtain. This distance is measured from the head surface or end part of the light curtain.
Tighten the M4 screws with a tightening torque of 2Nm.
Ä Position the upper clamping jaw of the C-shaped mounting bracket by screwing on the M3 screw. Do
not completely tighten the screw.
Ä Insert the device in the lower seat of the C-shaped mounting bracket with a slight incline. To do this,
use the corresponding lateral slot of the profile.
Ä Turn the device until the anchor of the upper jaw is reached.
Ä Tighten the M3 screw with a tightening torque of maximum 1.2Nm.
Ä For lengths up to 600mm, 2 C-shaped mounting brackets suffice; for longer lengths, 3 C-shaped
mounting brackets are recommended. The third mounting bracket is used as an additional support in
the middle.
1 M4x10 UNI 9327 screws, tightening torque: 2Nm max
2 Upper clamping jaw of the C-shaped mounting bracket
3 M3x8 UNI 9327 screw, tightening torque: 1.2Nm max
L Light curtain length
Fig.6.7: Mounting with C-shaped mounting brackets
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Mounting
6.2.4
Mounting with L-shaped mounting brackets
Ä Mount the lower L-shaped mounting bracket at the desired height. Tighten the M4 screws with a tight-
ening torque of 2Nm.
Ä Mount the retaining plate of the L-shaped mounting bracket so that the end part of the device protrudes
by no more than 1mm over the upper fitting surface of the plate.
Ä Clamp the device in the lower L-shaped mounting bracket and align with the respective reference
marks while doing so.
Ä Fasten the L part of the upper L-shaped mounting bracket with the M3 screws. Tighten the M3 screws
with a tightening torque of 1.2Nm.
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Mounting
1 mm
1
2
3
4
1 M3x8 UNI 9327 screws, tightening torque: 1.2Nm max
2 Retaining plate of the upper L-shaped mounting bracket
3 M4x10 UNI 9327 screws, tightening torque: 2Nm max
4 Lower L-shaped mounting bracket
Fig.6.8: Mounting with L-shaped mounting brackets
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Mounting
1/4 L
2
1
6.2.5
Mounting with L- and C-shaped mounting brackets
Ä Mount the lower L-shaped mounting bracket at the desired height in the lower part. Tighten the M4
screws with a tightening torque of 2Nm and the M3 screws with a tightening torque of 1.2Nm.
Ä Mount the C-shaped mounting bracket at the desired height. The recommended distance for the C-
shaped mounting bracket depends on the device; it is approximately 1/4 the length of the light curtain.
This distance is measured from the head surface or end part of the light curtain. Tighten the M4 screws
with a tightening torque of 1.2Nm.
Ä Position the upper clamping jaw of the C-shaped mounting bracket by screwing on the M3 screw. Do
not completely tighten the screw.
Ä Insert the device in the lower seat of the L-shaped mounting bracket with a slight incline. To do this,
use the corresponding lateral slot of the profile. Turn the device so that it snaps into the upper clamping
jaw of the C-shaped mounting bracket.
Ä Slide the device until it reaches the limit stop on the L-shaped mounting bracket.
Ä Tighten the M3 screw of the C-shaped mounting bracket with a tightening torque of 2Nm.
1 C-shaped mounting bracket
2 L-shaped mounting bracket
L Light curtain length
Fig.6.9: Mounting with L- and C-shaped mounting brackets
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6.3 Mounting accessories
2
1
3
Mounting
6.3.1
Deflecting mirror for multiple-side guarding
For multiple-side guarding, redirecting the protective field with one or two deflecting mirrors is economical.
To do this, Leuze electronic supplies:
• The UM60 deflecting mirror for mounting on the machine in various lengths (see chapter 15 "Order
guide and accessories")
• suitable BT-2UM60 swivel mounts
The range is reduced by approx.10% per deflection. A laser alignment aid with red light laser is recommended for the alignment of transmitter and receiver (Aligning of deflecting mirrors with the laser alignment
aid).
1 Transmitter
2 Receiver
3 UM60 deflecting mirrors
Fig.6.10: Arrangement with deflecting mirror for 2-side guarding of a point of operation
6.3.2
Mounting cascading
Connecting the cascade unit
Ä Mount all cascade units with the intended mounting brackets.
Ä Loosen the two fastening screws on the receiver and on the transmitter and remove the two connection
cables of the master and slave 1 (if present).
Ä Fasten the cascade cables in place of the removed connection cables. Make certain that the bending of
all cables is not less than 4mm.
Ä Connect the M12 connectors of slave1 to the M12 sockets of the cascade cables.
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3
1
2
3
1 Terminating cable
2 Cascade cable
3 Fastening screws of the receiver
Mounting
Fig.6.11: Mounting the cascade connection
Mounting with O-shaped mounting brackets
With the cascade configurations, the resolution of the edges is 40 mm.
All dimensions in mm
Fig.6.12: Mounting with O-shaped mounting brackets
Mounting with C-shaped mounting brackets
With the cascade configurations, the resolution of the edges remains at 14 mm.
All dimensions in mm
Fig.6.13: Mounting with C-shaped mounting brackets
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Mounting
Mounting with L-shaped mounting brackets
With the cascade configurations, the resolution of the edges is 26 mm.
All dimensions in mm
Fig.6.14: Mounting with L-shaped mounting brackets
Cascade with 90° resolution
When mounting the safety light curtains in the 90° cascade configuration (see chapter 3.3 "Cascading"),
the resolution at the edges is 18mm when using C-shaped mounting brackets or mounting bracket combinations that enable contact between the upper or lower front of a light curtain with the edge of the other
light curtains.
For models with a resolution of 24mm, the resolution at the edges is always retained if they have been
mounted correctly with the mounting brackets included in the scope of delivery.
All dimensions in mm
Fig.6.15: Cascade with 90° resolution
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7 Electrical connection
2
3
1
4
5
FE
WARNING
Faulty electrical connection or improper function selection may result in serious injury!
Ä Only allow qualified persons (see chapter 2.2 "Necessary competencies") to perform the
electrical connection.
Ä Make sure that the connection cables are protected against overcurrent.
Ä For access guarding, activate the start/restart interlock and make certain that it cannot be
unlocked from within the danger zone.
Ä Select the functions so that the safety sensor can be used as intended (see chapter 2.1 "In-
tended use and foreseeable misuse").
Ä Select the safety-relevant functions for the safety sensor (see chapter 4 "Functions").
Ä Always use both safety-related switching outputs OSSD1 and OSSD2 to shut down the dan-
gerous movement.
NOTICE
SELV/PELV!
Ä Acc. to EN60204-1, the external power supply must demonstrate the ability to bridge short-
term mains failures of up to 20ms. The power supply unit must ensure reliable disconnection from the mains supply (SELV/PELV).
Electrical connection
NOTICE
Laying cables!
Ä Lay all connection cables and signal lines within the electrical installation space or perma-
nently in cable ducts.
Ä Lay the cables and lines so that they are protected against external damages.
Ä For further information: see ISO13849-2, Table D.4.
NOTICE
For special EMC stress, the use of shielded cables is recommended.
7.1 Pin assignment transmitter and receiver
7.1.1
MLC520S transmitter
MLC 520S transmitters are equipped with a 5-pin M12 connector.
Fig.7.1: Pin assignment transmitter
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Tab.7.1: Pin assignment transmitter
2
3
1
4
5
FE
Pin Core color (CB-M12-xx000E-5GF) Transmitter
1 Brown +24VDC
2 White RESTART SELECTION:
• Bridge to pin5: automatic restart interlock
• Open and pin5 via normally closed contact to
24V: manual RES
• Pin2 and pin5 open: alignment mode
3 Blue 0V
4 Black Not used
5 Gray RESTART:
• Bridge to pin2: automatic restart interlock
• Via normally closed contact to 24V: manual
RES
• Pin2 and pin5 open: alignment mode
FE FE - functional earth, shield
Electrical connection
7.1.2
MLC520S receiver
MLC 520S receivers are equipped with a 5-pin M12 connector.
Fig.7.2: Pin assignment receiver
Tab.7.2: Pin assignment receiver
Pin Core color (CB-M12-xx000E-5GF) Receiver
1 Brown EDM: 24V via normally closed contact of a forced
relay
2 White OSSD1
Bridge to pin5: EDM deselected
3 Blue 0V
4 Black OSSD2
5 Gray EDM FBK/SELECTION:
Bridge to pin2: EDM deselected
Via normally closed contact to 24V: EDM active
FE FE - functional earth, shield
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8 Starting up the device
WARNING
Improper use of the safety sensor may result in serious injury!
Ä Make certain that the entire device and the integration of the optoelectronic protective de-
vice were inspected by qualified and instructed persons (see chapter 2.2 "Necessary competencies").
Ä Make certain that a dangerous process can only be started while the safety sensor is
switched on.
Prerequisites:
• Safety sensor mounted (see chapter 6 "Mounting") and connected (see chapter 7 "Electrical connection") correctly
• Operating personnel were instructed in proper use
• Dangerous process is switched off, outputs of the safety sensor are disconnected, and the system is
protected against being switched back on
Ä After start-up, check the function of the safety sensor (see chapter 9.1 "Before commissioning and fol-
lowing modifications").
Starting up the device
8.1 Switching on
Requirements for the supply voltage (power supply unit):
• Reliable mains separation is ensured.
• Current reserve of at least 2A is available.
Check operational readiness of sensor
Ä Check whether the LED indicators on the transmitter and receiver indicate the normal operating mode
(see chapter 3.4.1 "Operation indicators on the MLC520S transmitter/receiver").
ð The safety sensor is ready for use.
8.2 Aligning the sensor
NOTICE
Faulty or incorrect alignment may result in an operating fault!
Ä The alignment performed during start-up should only be performed by qualified persons (see
chapter 2.2 "Necessary competencies").
Ä Observe the data sheets and mounting instructions of the individual components.
NOTICE
In alignment mode, the OSSDs are not active.
The safety light curtain features a system that informs the user of the quality of the alignment. In alignment
mode, the LED indicator provides information on the quality and level of the alignment.
Perfect alignment is achieved when the optical axes of the first and last beam of the transmitter are aligned
with the optical axes of the corresponding beams of the receiver.
For the synchronization of transmitter and receiver, the beam closest to the cable tail is used: SYNC.
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Starting up the device
1
1 First optics = synchronization optics (SYNC)
Fig.8.1: Synchronization optics
The alignment function can be called up when starting the device if the RESTART contact is kept open for
at least 1 second (see chapter 7 "Electrical connection").
Fig.8.2: Timer for alignment mode
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Starting up the device
In alignment mode, the LED indicator indicates the signal strength measured by the receiver.
SPECIFICATION LED indicator OSSD DURING NOR-
MAL OPERATION
NOT ALIGNED,
SYNC NOT FOUND
SYNC FOUND, ONE
OR MORE BEAMS IN-
TERRUPTED
WEAK SIGNAL
STRENGTH, ALL OP-
TICS ARE FREE
MEDIUM-STRONG SIG-
NAL STRENGTH, ALL
OPTICS ARE FREE
MAXIMUM SIGNAL
STRENGTH,
ALL OPTICS ARE
FREE
Ä If the safety light curtain is optimally aligned, switch the transmitter and receiver off and back on again.
Ä Make certain that the RESTART contact is correctly connected.
8.3 Minimum distance for cascade system
OFF
OFF
ON
ON
ON
Fig.8.3: Minimum distance for cascade system
In a cascade system with a protected area width up to 3m, a minimum distance of 263mm must be provided between master and slave unit2 in order to avoid interference.
8.4 Selection of RESTART mode and operation
The interruption of a beam by a matt object results in the opening of the OSSD outputs and stopping of the
safety light curtain (SAFE condition).
Resetting normal operation of the device (closing the OSSD safety contacts = condition of NORMAL OPERATION) can be implemented in two different types:
• Automatic reset
After tripping, the device resumes its normal operation the moment the object is removed from the protected area.
• Manual reset
After tripping, the device does not resume its normal operation until the RESTART function has been
activated, with the prerequisite that the object has been removed from the protected area.
This condition, referred to as interlock, appears in the display (see chapter 3.4 "Display elements").
Leuze electronic MLC 520S 37
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Starting up the device
NORMAL
OPERATION
INTERLOCK
SAFE
Intercepted Beams
RESTART
Free
Beams
Intercepted
Beams
OSSD OFF OSSD OFFOSSD ON
Sender Sender
MANUAL RESTART AUTOMATIC RESTART
RESTART
SELECT ION
RESTART
24VDC
RESTART
SELECT ION
RESTART
N.C.
FLOAT
Fig.8.4: Selection of automatic/manual reset
Select automatic or manual reset via the corresponding connection of the RESTART input and the
RESTART SELECTION output of the transmitter (see chapter 7 "Electrical connection").
Fig.8.5: Selection of automatic/manual reset
NOTICE
If manual reset is selected, do not connect RESTART SELECTION.
As soon as the choice of mode is detected by the transmitter, the receiver is always in alignment mode on
start-up (see chapter 8.2 "Aligning the sensor") in order to then switch to the selected mode after the first
correct alignment.
CAUTION
Carefully assess the risk conditions and the RESET mode!
Automatic RESET mode is potentially unsafe when guarding access points in danger zones if it
is possible for the user to completely pass beyond the area being monitored.
Ä Manual reset required
Fig.8.6: Time of manual reset
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8.5 Unlocking start/restart interlock
The reset button can be used to unlock the start/restart interlock. In this way, the responsible person can
restore the ON state of the safety sensor following process interruptions (due to triggering of protective
function, failure of the voltage supply).
WARNING
Premature unlocking of the start/restart interlock may result in serious injury!
If the start/restart interlock is unlocked, the system can start up automatically.
Ä Before unlocking the start/restart interlock, make certain that no people are in the danger
zone.
The LED indicator of the receiver indicates that the restart is disabled (OSSDs off) or, if RES is activated,
the protective field is clear (ready to be unlocked).
Ä Make certain that the active protective field is clear.
Ä Make certain that there are no people in the danger zone.
Ä Press and release the reset button within 0.5 to 4s. The receiver switches to the ON state.
Starting up the device
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9 Testing
NOTICE
Ä Safety sensors must be replaced at the end of their mission time (see chapter 14 "Technical
data").
Ä Always exchange entire safety sensors.
Ä Observe any nationally applicable regulations regarding the tests.
Ä Document all tests in a comprehensible manner and include the configuration of the safety
sensor along with the data for the safety- and minimum distances in the documentation.
9.1 Before commissioning and following modifications
WARNING
Unpredictable machine behavior during start-up may result in serious injury!
Ä Make certain that there are no people in the danger zone.
Ä Before they begin work, train the operators on their respective tasks. The training is the responsibility of
the operating company.
Ä Attach notes regarding daily testing in the respective national language of the operator on the machine
in a highly visible location, e.g. by printing out the corresponding chapter (see chapter 9.3 "Periodically
by the operator").
Ä Test the electrical function and installation according to this document.
Acc. to IEC62046 and national regulations (e.g. EU directive2009/104/EC), tests are to be performed by
competent persons (see chapter 2.2 "Necessary competencies") in the following situations:
• Prior to commissioning
• Following modifications to the machine
• After longer machine downtime
• Following retrofitting or new configuration of the machine
Ä As preparation, check the most important criteria for the safety sensor according to the following check-
list (see chapter 9.1.1 "Checklist for integrator – to be performed prior to commissioning and following
modifications"). Completing the checklist does not replace testing by competent persons (see chapter
2.2 "Necessary competencies")!
ð Not until proper function of the safety sensor is ascertained may it be integrated in the control circuit of
the system.
Testing
9.1.1
Leuze electronic MLC 520S 40
Checklist for integrator – to be performed prior to commissioning and following modifications
NOTICE
Completing the checklist does not replace testing by a qualified person (see chapter 2.2
"Necessary competencies")!
Ä If you answer one of the items on the following check list with no, the machine must no
longer be operated.
Ä IEC62046 contains additional recommendations on testing protective devices.
Tab.9.1: Checklist for integrator – to be performed prior to the initial start-up and following modifications
Check: Yes No not ap-
plicable
Is the safety sensor operated acc. to the specific environmental conditions that are to be maintained (see chapter 14 "Technical data")?
Is the safety sensor correctly aligned and are all fastening screws and
connectors secure?
Page 41
Testing
Check: Yes No not ap-
plicable
Are safety sensor, connection cables, connectors, protection caps and
command devices undamaged and without any sign of manipulation?
Does the safety sensor satisfy the required safety level (PL, SIL, category)?
Are both safety-related switching outputs (OSSDs) integrated in the
downstream machine control acc. to the required safety category?
Are switching elements that are controlled by the safety sensor monitored according to the required safety level (PL, SIL, category) (e.g.,
contactors through EDM)?
Are all points of operation near the safety sensor accessible only
through the protective field of the safety sensor?
Are the necessary additional protective devices in the immediate surroundings (e.g., safety guard) properly mounted and secured against
tampering?
If it is possible to be present undetected between the safety sensor and
point of operation: is an assigned start/restart interlock functional?
Is the command device for unlocking the start/restart interlock mounted
in such a way that it cannot be reached from within the danger zone
and so that the complete danger zone can be seen from the installation
location?
Has the maximum stopping time of the machine been measured and
documented?
Is the required safety distance maintained?
Does interruption with a test object intended for this purpose cause the
dangerous movement(s) to stop?
Is the safety sensor effective during the entire dangerous movement(s)?
Is the safety sensor effective in all relevant operating modes of the machine?
Is start-up of dangerous movements reliably prevented if an active light
beam or the protective field is interrupted with a test object intended for
this purpose?
Was the sensor detection capacity successfully tested (see chapter
9.3.1 "Checklist – periodically by the operator")?
Were distances to reflective surfaces taken into account during configuration and no reflection bypasses subsequently detected?
Are notices for regular testing of the safety sensor legible to the operator and are they located in a highly visible location?
Are changes to the safety function (e.g. SPG, blanking, protective field
switchover) not easy to achieve through tampering?
Are settings that could result in an unsafe state possible only by means
of key, password or tool?
Are there incentives that pose stimulus for tampering?
Were the operators instructed prior to starting work?
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9.2 To be performed periodically by competent persons
The reliable interaction of safety sensor and machine must be regularly tested by qualified persons (see
chapter 2.2 "Necessary competencies") in order to detect changes to the machine or impermissible tampering with the safety sensor.
Acc. to IEC62046 and national regulations (e.g., EU directive 2009/104/EC), tests of elements which are
subject to wear must be performed by qualified persons (see chapter 2.2 "Necessary competencies") at
regular intervals. Testing intervals may be regulated by nationally applicable regulations (recommendation
acc. to IEC62046: 6months).
Ä Only allow testing to be performed by qualified persons (see chapter 2.2 "Necessary competencies").
Ä Observe the nationally applicable regulations and the time periods specified therein.
Ä As preparation, observe the checklist (see chapter 9.1 "Before commissioning and following modifica-
tions").
9.3 Periodically by the operator
The function of the safety sensor must be checked depending on the given risk according to the following
checklist so that damages or prohibited tampering can be detected.
Depending on the risk assessment, the test cycle must be defined by the integrator or operating company
(e.g., daily, on shift changes, ...) or is specified by national regulations or regulations of the employer's liability insurance association and may be dependent on the machine type.
Due to complex machines and processes, it may be necessary under certain circumstances to check some
points at longer time intervals. Observe the classification in “Test at least” and “Test when possible”.
Testing
9.3.1
NOTICE
For larger distances between transmitter and receiver and when using deflecting mirrors, a second person may be necessary.
WARNING
Unpredictable machine behavior during the test may result in serious injury!
Ä Make certain that there are no people in the danger zone.
Ä Before they begin work, train the operators on their respective tasks and provide suitable
test objects and an appropriate test instruction.
Checklist – periodically by the operator
NOTICE
Ä If you answer one of the items on the following check list with no, the machine must no
longer be operated.
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Testing
Tab.9.2: Checklist – regular function test by trained operators/persons
Test at least: Yes No
Are safety sensor and connectors securely mounted and free of obvious signs of damage,
changes or tampering?
Were no obvious changes made to access or entry possibilities?
Test the effectiveness of the safety sensor:
• The LED1 on the safety sensor must illuminate green (see chapter 3.4.1 "Operation
indicators on the MLC520S transmitter/receiver").
• Interrupt an active beam or the protective field (see figure) with a suitable, opaque test
object:
Checking the protective field function with test rod (only for safety light curtains with a resolution of 14…40mm).
For light curtains with different resolution ranges, this check is to be performed separately
for each resolution range.
• Does the OSSD LED on the receiver illuminate constantly red while the protective field
is interrupted?
When possible, test during running operation: Yes No
Protective device with approach function: during machine operation, the protective field is
interrupted with the test object – are the obviously dangerous machine parts stopped without noticeable delay?
Protective device with presence detection: the protective field is interrupted with the test
object – does this prevent operation of the obviously dangerous machine parts?
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10 Maintenance
NOTICE
Faulty operation if transmitter and receiver are soiled!
The surfaces of the front screen of transmitters, receivers and, where applicable, deflecting mirror must not be scratched or roughened at the positions where beams enter and exit.
Ä Do not use chemical cleaners.
Prerequisites for cleaning:
• The system is safely shut down and protected against restart.
Ä Clean the safety sensor periodically depending on the degree of contamination.
NOTICE
Prevent electrostatic charging of the front screens!
Ä To clean the front screens of transmitter and receiver, use only damp cloths.
Maintenance
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11 Troubleshooting
11.1 What to do in case of failure?
After switching the safety sensor on, the display elements (see chapter 3.4 "Display elements") assist in
checking the correct functionality and in faultfinding.
In case of error, you can determine the error from the LED displays. With the error message you can determine the cause of the error and initiate measures to rectify it.
NOTICE
If the safety sensor responds with an error display, you will often be able to eliminate the
cause yourself!
Ä Switch off the machine and leave it switched off.
Ä Analyze and eliminate the cause of the fault using the following table.
Ä If you are unable to rectify the fault, contact the Leuze electronic branch responsible for you
or call the Leuze electronic customer service (see chapter 13 "Service and support").
11.2 Operating indicator of the LEDs
Tab.11.1: LED indicators at the transmitter - causes and measures
Troubleshooting
Operating
mode
NORMAL
OPERATION
LOCKOUT
ERROR
Specifica-
tion
EMISSION
F1:
Microprocessor error
F2:
Optics error
F12:
Cascade
error
LED indicator Measure
Internal error
Check the operating
conditions and any possible cause of electrical
interference, then switch
the device off and back
on again (see chapter
14 "Technical data").
Optical scan error.
Check any possible
cause of electrical interference, then switch the
device off and back on
again.
Cascade communication
error.
Check the cascade connection or the mounting
of the terminator (see
chapter 6.3.2 "Mounting
cascading")
F13:
Reset error
Leuze electronic MLC 520S 45
Reset error.
Check the connection of
the RESTART SELECTION pin (see chapter
8.4 "Selection of
RESTART mode and
operation").
Page 46
Tab.11.2: LED indicators at the receiver - causes and measures
Troubleshooting
Operating
mode
ALIGN-
MENT
NORMAL
OPERA-
TION ONLY
MANUAL
RESET
NORMAL
OPERA-
TION
Specifica-
LED indicator Measure
tion
Not
aligned,
SYNC not
occupied
Medium-
strong sig-
nal
strength,
SYNC oc-
cupied
Align device (see chap-
ter 8.2 "Aligning the sen-
sor").
Follow the instructions
for implementing the
correct alignment
process or connect the
RESTART input on the
transmitter to switch to
the normal operating
mode (see chapter 8.4
Maximum
signal
"Selection of RESTART
mode and operation").
strength
Interlock,
free
beams
Press the RESTART
button for at least 0.5
seconds to restart the
device in the normal op-
erating mode
OSSD ON Normal operating mode
OSSD
OFF
EDM ac-
tive
Safety status
Remove all obstacles or
correctly align the device
EDM function enabled
Leuze electronic MLC 520S 46
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Troubleshooting
Operating
mode
LOCKOUT
ERROR
Specifica-
tion
F1:
Micropro-
cessor er-
ror
F2:
Optics er-
ror
F3:
EDM error
LED indicator Measure
Internal error.
Check the operating
conditions and any pos-
sible cause of electrical
interference. Switch the
device off and back on
again (see chapter 14
"Technical data").
Optical scanning error.
Check any possible
cause of optical and
electrical interference.
Switch the device off
and back on again.
EDM error.
Check the wiring and
check for contactor
faults, then switch the
device off and on again
(see chapter 4.2 "EDM
contactor monitoring").
F12:
Cascade
error
F13:
Reset er-
ror
F23:
OSSD er-
ror
Cascade communication
error.
Check the cascade con-
nection or the mounting
of the terminator (see
chapter 6.3.2 "Mounting
cascading").
Restart function error.
Check the connection of
the restart button and
any possible cause of
optical interference, then
switch the device off and
back on again.
Error at safety outputs.
Check that the connec-
tion is correct and any
possible cause of electri-
cal interference, then
switch the device off and
back on again (see
chapter 7 "Electrical
connection").
Supply er-
ror
Check that the connec-
tion is correct (see chap-
ter 7 "Electrical connec-
tion").
Leuze electronic MLC 520S 47
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12 Disposing
Ä For disposal observe the applicable national regulations regarding electronic components.
Disposing
Leuze electronic MLC 520S 48
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13 Service and support
24-hour on-call service at:
+49 7021 573-0
Service hotline:
+49 7021 573-123
E-mail:
service.protect@leuze.de
Return address for repairs:
Servicecenter
Leuze electronic GmbH + Co. KG
InderBraike1
D-73277Owen/Germany
Service and support
Leuze electronic MLC 520S 49
Page 50
14 Technical data
14.1 General specifications
Tab.14.1: Protective field data
Technical data
Physical resolution [mm]
Operating range [m] Protective field height [mm]
min. max. min. max.
14 0.2 6 150 1200
24 0.2 6 150 1200
Tab.14.2: Safety-relevant technical data
Type in accordance with IEC61496 Type4
SIL in accordance with IEC61508 SIL3
SILCL in accordance with IEC62061 SILCL3
Performance Level (PL) in accordance with ISO13849-1 PLe
Category in accordance with ISO13849-1 Cat. 4
Average probability of a failure to danger per hour (PFHd) 2.64x10-91/h
Mission time (TM) 20 years
Tab.14.3: General system data
Connection technology M12, 5-pin (transmitter)
M12, 5-pin (receiver)
Supply voltage Uv, transmitter and receiver +24V, ± 20%
Residual ripple of the supply voltage ± 5% within the limits of U
v
Current consumption - transmitter 55mA
Current consumption receiver 145mA (without load)
Synchronization Optical between transmitter and receiver
Protection class III
Degree of protection IP 65
Ambient temperature, operation -10…+55°C
Ambient temperature, storage -25…70°C
Relative humidity (non-condensing) 15…95%
Vibration resistance 50m/s2 acceleration, 10-55 Hz in acc. with
IEC60068-2-6; 0.35mm amplitude
Shock resistance 98.1m/s2 acceleration, 16ms acc. to
IEC60068-2-29, 1000 impacts per spatial axis
Profile cross section 15.4mmx32.6mm
Dimensions see chapter 14.2 "Dimensions, weight, response
time"
Weight see chapter 14.2 "Dimensions, weight, response
time"
Leuze electronic MLC 520S 50
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Tab.14.4: System data - transmitter
Technical data
Transmitter diodes, class in accordance with
1
IEC60825-1
Wavelength 850 nm (infrared)
Tab.14.5: System data receiver, indication signals and control signals
Pin Signal Type Electrical data
1 RES/STATE Input:
Output:
Against +24V: 15mA
Against 0V: 80mA
3 EDM Input: Against 0V: 15mA
4 RES Input: Against 24V: 15mA
Tab.14.6: Technical data of the electronic safety-related switching outputs (OSSDs) on the receiver
Safety-related PNP transistor outputs
Minimum Typical Maximum
(short-circuit monitored, cross-circuit
monitored)
Switching voltage high active (Uv-1.5V) 18V 22.5V 27 V
Switching voltage low 0V +2.5V
Switching current 200mA 300mA
Residual current <2µA 200µA
In the event of a failure (if the
0V cable is interrupted), each of
the outputs behaves as a 120kΩ
resistor to Uv. A downstream
safety PLC must not detect this
as a logical “1”.
Load capacity 1µF
Load inductivity 2H
Permissible wire resistance for load <200Ω
Note the additional restrictions
due to cable length and load current.
Permissible wire cross section 0.25mm
Permissible cable length between receiver
2
20m
and load
Test pulse width 100μs
NOTICE
The safety-related transistor outputs perform the spark extinction. With transistor outputs, it is
therefore neither necessary nor permitted to use the spark extinction circuits recommended by
contactor or valve manufacturers (RC elements, varistors or recovery diodes), since these considerably extend the decay times of inductive switching elements.
Tab.14.7: Patents
US patents US 6,418,546 B
Leuze electronic MLC 520S 51
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14.2 Dimensions, weight, response time
Dimensions, weight and response time are dependent on
• the resolution
• the length
Technical data
All dimensions in mm
L Length/protective field height (controlled height)
L
T
Fig.14.1: Dimensions of transmitter and receiver
Tab.14.8: Protective field height, number of beams and response time
Protective field
Profile length
height
Resolution 14mm Resolution 24mm
Number of beams Response time Number of beams Response time
150 15 7 8 7
210 21 8 11 7
270 27 8 14 8
300 30 8 16 8
330 33 9 17 8
360 36 9 19 8
390 39 10 20 8
420 42 10 22 9
450 45 10 24 9
480 48 10 25 9
510 51 11 27 9
540 54 11 28 9
570 57 11 30 9
600 60 11 32 9
630 63 12 33 10
660 66 12 35 10
690 69 13 36 10
720 72 13 38 10
Leuze electronic MLC 520S 52
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Technical data
Protective field
height
Number of beams Response time Number of beams Response time
Resolution 14mm Resolution 24mm
750 75 13 40 10
780 78 13 41 10
810 81 14 43 11
840 84 14 44 11
870 87 14 46 11
900 90 14 48 11
930 93 15 49 11
960 96 15 51 11
990 99 16 52 12
1020 102 16 54 12
1050 105 16 56 12
1080 108 16 57 12
1110 111 17 59 12
1140 114 17 60 12
1170 117 17 62 13
1200 120 17 64 13
Transmitter/receiver weight
P [g] = L [mm] x 5 + 50
Example:
Length/protective field height L = 1200 mm
Weight P = 6050 g
Leuze electronic MLC 520S 53
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14.3 Dimensioned drawings: Accessories
Technical data
All dimensions in mm
Fig.14.2: C-shaped mounting bracket
All dimensions in mm
Fig.14.3: O-shaped mounting bracket
Leuze electronic MLC 520S 54
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Technical data
All dimensions in mm
Fig.14.4: L-shaped mounting bracket
Leuze electronic MLC 520S 55
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Technical data
All dimensions in mm
Fig.14.5: Cascade cable
Leuze electronic MLC 520S 56
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15 Order guide and accessories
Nomenclature
Part designation:
MLCxxx-ooo-aa-hhhh
Tab.15.1: Part number code
MLC Safety sensor
xxx Series: 520 for MLC520S
aa Resolution:
14: 14mm
24: 24mm
hhhh Protective field height:
150…1200: from 150mm to 1200mm
ooo Option:
S: Slimline version
Order guide and accessories
Tab.15.2: Part descriptions, examples
Examples for part desig-
Properties
nation
MLC520-S-14-600 Transmitter/receiver, resolution 14mm, protective field height 600mm
MLC520-S-24-900 Transmitter/receiver, resolution 24mm, protective field height 900mm
Scope of delivery
• Transmitter unit
• Receiver unit
• 1 set with 4 mounting brackets, model BT-MLC-S-O
• 2 sets with 2 mounting brackets, model BT-MLC-S-C (additional set is required for protective field
lengths of 600mm and longer)
Leuze electronic MLC 520S 57
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Order guide and accessories
Tab.15.3: Part numbers of MLC 520S transmitter/receiver depending on resolution and protective field height
Protective field height hhhh
[mm]
14mm
MLC520-S-14-hhhh
24mm
MLC520-S-24-hhhh
150 68601015 68602015
210 68601021 68602021
270 68601027 68602027
300 68601030 68602030
330 68601033 68602033
360 68601036 68602036
390 68601039 68602039
420 68601042 68602042
450 68601045 68602045
480 68601048 68602048
510 68601051 68602051
540 68601054 68602054
570 68601057 68602057
600 68601060 68602060
630 68601063 68602063
660 68601066 68602066
690 68601069 68602069
720 68601072 68602072
750 68601075 68602075
780 68601078 68602078
810 68601081 68602081
840 68601084 68602084
870 68601087 68602087
900 68601090 68602090
930 68601093 68602093
960 68601096 68602096
990 68601099 68602099
1020 68601102 68602102
1050 68601105 68602105
1080 68601108 68602108
1110 68601111 68602111
1140 68601114 68602124
1170 68601117 68602117
1200 68601120 68602120
Leuze electronic MLC 520S 58
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Order guide and accessories
Tab.15.4: Accessories
Part no. Article Description
Connection cables for MLC 520S transmitter/receiver, unshielded
50133841 KD U-M12-5A-P1-050 Connection cable, 5-pin, 5m long
50132534 KD U-M12-5A-P1-100 Connection cable, 5-pin, 10m long
429088 CB-M12-15000-5GF Connection cable, 5-pin, 15m long
429089 CB-M12-25000-5GF Connection cable, 5-pin, 25m long
429281 CB-M12-50000-5GF Connection cable, 5-pin, 50m long
Mounting technology
424440 BT-MLC-S-C C-shaped mounting brackets, 2x
424441 BT-MLC-S-L L-shaped mounting brackets, 2x
424442 BT-MLC-S-O O-shaped mounting brackets, 4x
50137531 CB-M12-MLC-S-100-5TP Cascade cable, L=0.1m
50137532 CB-M12-MLC-S-500-5TP Cascade cable, L=0.5m
50137533 CB-M12-MLC-S-1000-5TP Cascade cable, L=1m
Deflecting mirror
529601 UM60-150 Deflecting mirror, mirror length 210mm
529603 UM60-300 Deflecting mirror, mirror length 360mm
529604 UM60-450 Deflecting mirror, mirror length 510mm
529606 UM60-600 Deflecting mirror, mirror length 660mm
529607 UM60-750 Deflecting mirror, mirror length 810mm
529609 UM60-900 Deflecting mirror, mirror length 960mm
529610 UM60-1050 Deflecting mirror, mirror length 1110mm
529612 UM60-1200 Deflecting mirror, mirror length 1260mm
430105 BT-2UM60 Mounting bracket for UM60, 2x
Test rods
430414 AC-TR14-S Test rod 14mm
430424 AC-TR24-S Test rod 24mm
Leuze electronic MLC 520S 59
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16 EU/EC Declaration of Conformity
EU/EC Declaration of Conformity
Leuze electronic MLC 520S 60
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