SICK WSU 26/2, WEU 26/2 Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

ECHNICAL D ESCRIPTION

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

The information contained in this document may be revised or supplemented without prior notice.

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

Contents

1 Document Information .................................................................................................. 5

1.1 About this document ..................................................................................................... 5

1.2 Target group .......................................................................................................................5

1.3 Scope of information ....................................................................................................6

1.4 Symbols used in this document ............................................................................6

2 Safety....................................................................................................................................... 7

2.1 General safety advice and protective measures........................................ 7

2.2 Application areas ............................................................................................................. 8

2.3 Intended use of the device ...................................................................................... 9

2.4 Environmental compatibilty ....................................................................................... 9

3 Product Description..................................................................................................... 10

3.1 Characteristics................................................................................................................ 10

3.2 Device functionality..................................................................................................... 10

4 Mounting ............................................................................................................................ 11

4.1 Positioning the sensors ........................................................................................... 11

4.2 Safety distance.............................................................................................................. 11

4.3 Distance to reflective surfaces........................................................................... 13

4.4 Multiple safeguarding ................................................................................................ 15

4.4.1 Mutual interference ................................................................................................. 16

4.5 Mechanical mounting.................................................................................................. 16

4.5.1 Corner mirrors ............................................................................................................. 18

5 Electrical Installation................................................................................................. 19

5.1 Test instructions............................................................................................................ 20

5.2 Spark suppression....................................................................................................... 20

5.3 Short-circuit monitoring............................................................................................. 21

5.4 Overvoltage protection (fuse)............................................................................... 21

5.5 Wiring diagram ................................................................................................................ 22

5.6 Alignment of WSU and WEU ................................................................................... 30

5.6.1 Alignment of WSU and WEU with Alignment Aid AR 60.................... 31

6 Test Instructions ............................................................................................................ 32

6.1 Pre-commissioning tests ......................................................................................... 32

6.2 Regular testing of the safety device by competent personnel...... 32

6.3 Daily testing of the safety module by competent personnel .......... 33

7 Maintenance .................................................................................................................... 34

8 Diagnostic Elements ................................................................................................... 35

9 Technical Data ............................................................................................................... 36

9.1 Overview technical data ........................................................................................... 36

9.2 Dimensional drawings ................................................................................................ 38

10 At a glance: Comparison of old versus new devices............................ 42

11 Selection Table ............................................................................................................ 43

11.1 Conversion list ............................................................................................................. 44

12 Accessories Selection Table ............................................................................... 45

13 Checklist .......................................................................................................................... 46

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

Document Information

Abbreviations

Chapter 1

PDM

WSU

WEU

OSSD

AOPD

Power-driven machinery (machinery, plant)

Photoelectric Safety Switch: Sender unit

Photoelectric Safety Switch: Receiver unit

Output Signal Switching Device

Active Optoelectronic Protective Device

1 Document Information

1.1 About this document

This document provides instructions for the operation of the WSU/WEU photoelectric safety switch. It contains information on

 Application  Mounting  Electrical installation  Commissioning  Maintenance  Ordering

1.2 Target group

The target group of this document is those who install, commission and use the WSU/WEU photoelectric safety switch.

Chapter 1

Document Information

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

1.3 Scope of information

This technical description contains information on how to install, commission and operate the device. Official and legal regulations must always be observed. It is not possible to provide comprehensive information on all these requirements in this document. In Germany, for example, the Trade Association Directives (ZH 1/597 and ZH 1/281) in particular must be observed.

Further information on health and safety with respect to optoelectronic guarding systems can be obtained directly from your local SICK distributor, e. g. Safe Machines (SICK guidelines on the operation of optoelectronic guarding systems).

1.4 Symbols used in this document

Some information in this document is highlighted to ease rapid access to this information:

Note

Explanation

Recommendation

WARNING

A note provides information on special features of the device.

An explanation gives basic information.

A recommendation assists in deciding upon the best action.

Warning!

A warning indicates actual or potential hazards. This is to reduce the risk of accidents.

Always read warning notices carefully and follow them closely.

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

Safety

Chapter 2

Safety

WARNING

The devices can only perform their safety function if they are used correctly and integrated into the process in a failsafe manner.

The WSU/WEU photoelectric safety switch meets the requirements of Type 4 Safety Devices as stipulated in EN 61 496-1 and pr EN 50 100-2.

2.1 General safety advice and protective measures

1 National and international regulations apply for the operation of non-

contact protection equipment as well as for commissioning and regular maintenance checks, in particular

 Machinery Safety Regulation 98/37 EC  Provision and Use of Work Equipment Regulations

89/665 EEC

 Relevant safety regulations  Accident prevention regulations and safety guidelines

It is the responsibility of the manufacturers and operators of the machine on which SICK protection equipment is used to discuss all safety legislation, which may apply, with the responsible authorities and to observe these rules and regulations.

2 Furthermore, our notes, in particular the Test Regulations (see

section ‘Tests’) in this Technical Description or the Operating Instructions (such as use, assembly, installation or integration in the machine control unit) must be observed.

3 The tests must be performed by qualified personell or by specially

authorised and instructed personnel and must be documented in

such a way as to be viewed and understood at any time.

4 These Operating Instructions shall be given to the employee

(operator) working with the machine on which SICK guarding systems are installed. The employee shall be trained for their job and operation of the equipment by a competent person.

5 The Test Protocol relating to use of the non-contact safety device is

printed at the end of these Technical Description. Acceptance testing should be performed on the basis of that protocol.

6 Mounting and connection may only be done by qualified personnel.

Before commissioning, the mounting and connection must be inspected by the operator’s responsible staff member, as is required by the standards and directives of the specific country.

Chapter 2

Safety

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

2.2 Application areas

The WSU/WEU 26/2 photoelectric safety switch is used as an access safety system to hazardous areas around machinery or plant. The device is securely mounted in the access area at a pre-determined safe distance from the hazardous point. When the light beam is interrupted the device transmits an emergency stop signal to the machinery or plant.

Point-of-operation

Mechanical

mechanische Absicherung

guarding

Gefahrstelle

Zugangssicherung

Entry/exit guarding

mit WSU/WEU

with WSU/WEU

Direction of entry

Eintrittsrichtung

into hazardous

in Gefahrbereich

area

Fig. 1: Entry/exit safeguarding using a WSU/WEU 26/2

The following key points are important for correct operation (Fig. 2):

Beam diameter

Lichtstrahldurchmesser

23 mm

WSU WEU

23 mm

0.5 to 18 m 15 to 70 m

Fig. 2: System construction of the WSU/WEU 26/2

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

Safety

Chapter 2

2.3 Intended use of the device

The WSU/WEU photoelectric safety switch may only be used as specified in Section 2.2 Application areas. The device may be operated only in accordance with its technical specifications. Any other use or modification – including during mounting and installation – will invalidate any guarantee and any claim against SICK AG.

2.4 Environmental compatibility

The WSU/WEU photoelectric safety switch is designed to have the lowest possible impact on the environment. It neither emits nor contains any environmentally damaging substances, and consumes minimal quantities of energy and resources.

Disposal

Unusable systems or systems beyond repair must be disposed of in accordance with the regulations on refuse disposal currently valid in the respective country.

The aluminium housing should be recycled. If possible, remove the plastic front panel.

All electronic components can be simply dismantled. They should be disposed of as special waste. SICK AG will not accept back unusable systems or systems beyond repair.

When dismantling and disposing of components, provisions relating to occupational safety, the environment and disposal should be observed.

Chapter 3

Product Description

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

Product Description

3.1 Characteristics

Special characteristics of the WSU/WEU 26/2 photoelectric safety switch are:

 easy installation  universal functionality  solid construction  various connecton options  universal power supply  wide scanning range

3.2 How the device functions

The housing of WSU/WEU consists of die-cast Aluminium. In the WSU, an infrared sender diode emits pulse modulated light (Fig. 3). If the light path is uninterrupted the output relays in the WEU are deenergized.

3 4

5 6

11 1 10

1 Connection for power supply 2 Power supply 3 Clock generator 4 Sender diode 5 LED, WSU 6 LED, WEU

Fig. 3: Principle of function of the WSU/WEU 26/2, AC version

Light beam

Lichtbündel

10 Outputs 11 Test contact

7 Photoelectric converter 8 Amplifier 9 Relay with positively-guided contacts

7 8

Diagnostic lights on the instruments signal the various operating conditions (see 8 Diagnostic Elements). Their display, however, is not safety related. The diagnostic lights also serve as error diagnostics, see 8, Diagnostic Elements.

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

Mounting

Chapter 4

Mounting

4.1 Positioning the sensors

The WSU/WEU can be operated in any position. Regulations regarding safety distances must be observed as well as sufficient height of beams above floor.

4.2 Safety distance

The WSU/WEU must be mounted such that, if the light beam is broken during hazardous movement of the machinery, the point-of-operation can only be reached when this hazardous movement has ceased. For this purpose, a safety distance S must be maintained between the nearest trapping point and the light beam (Fig. 4). The safety distance depends on the machine stopping time and on the approach speed of the personnel.

Point-of-operation

Mechanical

mechanische

guarding

Absicherung

Zugangssicherung

Entry/exit guarding

mit WSU/WEU

with WSU/WEU

Eintrittsrichtung

Direction of entry

in Gefahrbereich

into hazardous area

Fig. 4: Safety distance S to light beam

Gefahrstelle

The machine stopping time must be determined by repeated measurements under practical conditions. 1.6 m/s is the recommended (by EN 999) approach speed. The safety distance is calculated as follows:

Chapter 4

Mounting

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

S = K · T + C

S Safety distance (mm) K Approach speed 1.6 m/s T Machine stopping time (ms) + response time of WEU

(see Technical Data)

C Dependent on number of beams (1, 2, or 3), see Table 1

Table 1 shows which C value must be used for which application.

Number of beams 1 2 3

Height of beam(s) 750 400 300 above floor (mm) 900 700

C 1200 850 850

Tab 1: Height of beams above floor

1100

WARNING

Maintain safety distance!

The WSU/WEU must be mounted such that, if the light beam is broken during hazardous movement of the machinery, the point-of-operation can only be reached when the power-driven machinery is no longer in a hazardous state.

For this purpose, a safety distance must be maintained between the light beam and the nearest boundary of the point-of-operation. This safety distance is determined according to pr EN 999.

EN 999 Safety of machinery Approach speed of body parts for arrangement of protective systems

Danger of non-detection

People within the hazardous area but outside the light beam are not detected. It must, however, be ensured that any hazardous state can only be initiated when there is no one in the hazardous area.

The WSU/WEU may not be utilised as a hand- and finger protection system.

Use and mounting of the protective systems is subject to the relevant official rules and regulations. These provisions differ depending on the area of application.

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

Mounting

Chapter 4

4.3 Distance to reflective surfaces

Reflective surfaces located (placed or fixed) within the sender and receiver range, may cause reflection and thus prevent an obstacle from being reliably detected (Fig. 5). For this reason, a minimum distance “a” from reflective surfaces to the optical axis (linear connection between transmitter and receiver) must be maintained (Fig. 6). The distance “a” is dependent on the distance between the sender and receiver (Fig. 7). Testing for spurious reflection is described in Section 6 Test

Instructions.

Entry direction

Central beam

Obstacle

Beam array broken

WSU WEU

Reflective object (e. g. material container)

Boundary of point-ofoperation

Deflection: “a” should be set higher because of the reflection

Fig. 5: Incorrect mounting: reflective object in divergent light beam. No detection of the obstacle due to reflection. No protection.

Entry direction

Central beam

WSU WEU

4˚

Reflective object (e. g. material container)

Boundary of point-ofoperation

Obstacle

Beam array broken

4˚

Fig. 6: Correct mounting, correctly aligned: reflective object outside divergent light beam. No reflection. The obstacle is clearly detected.

Chapter 4

Mounting

a (mm)

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

2500

2000

1500

1000

500 400 300 200 100

WSU WEU

4˚

Fig. 7: Distance “a” as a function of scanning range RW

a (18 m)

a (70 m)

RW (m)

RW I

RW II

Technical Description

WSU 26/2 – WEU 26/2

Photoelectric Safety Switch

Mounting

Chapter 4

4.4 Multiple safeguarding

When using two WSU/WEU units in a protective system, the possibility of mutual interference must be excluded. Since the light beam of the WSU diverges, the cross-section of the beam increases as the distance between the WSU and WEU increases. The following conditions must therefore be met when arranging the WSU/WEU (Fig. 8).

Correct

Wrong

Correct

Corner mirror

Wrong

Corner mirror

Fig. 8: Safeguarding a hazardous area with WSU/WEU

+ 33 hidden pages

SICK WSU 26/2, WEU 26/2 Technical Description

Specifications and Main Features

Frequently Asked Questions

User Manual