EN 12478:2003

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NORMAEUROPEA

Pagina IUNI EN 12779:2005

© UNIRiproduzione vietata. Tutti i diritti sono riservati. Nessuna parte del presente documentopuò essere riprodotta o diffusa con un mezzo qualsiasi, fotocopie, microfilm o altro, senzail consenso scritto dell’UNI.

www.uni.com

UNI

Ente Nazionale Italiano

di Unificazione

Via Battistotti Sassi, 11B20133 Milano, Italia

UNI EN 12779

LUGLIO 2005

Sicurezza delle macchine per la lavorazione del legno

Sistemi fissi d’estrazione di trucioli e di polveri

Prestazioni correlate alla sicurezza e requisiti di sicurezza

Safety of woodworking machines

Chip and dust extraction systems with fixed installation

Safety related performances and safety requirements

La norma specifica i requisiti delle prestazioni correlate alla sicu-rezza e specifica i metodi per l’eliminazione dei pericoli o le misureche devono essere adottate per limitare i pericoli dei sistemi fissi diestrazione di trucioli e polveri, connessi alle macchine per la lavo-razione del legno, progettate per tagliare legno massiccio, pannellidi particelle, pannelli di fibra o legno compensato ed anche questi

materiali ricoperti con laminati plastici o bordi.

TT EE SS TT OO II NN GG LL EE SS EE

La presente norma è la versione ufficiale in lingua inglese della

norma europea EN 12779 (edizione dicembre 2004).

ICS 79.120.10

Documento contenuto ne l prodot to UNI 626 ed iz ione 2006 .

E ' v ie ta to l 'uso in re te de l s ingo lo documento e la sua r iprod uz ione. E ' autor izzata la s tampa per uso in terno.

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© UNI Pagina IIUNI EN 12779:2005

Le norme UNI sono elaborate cercando di tenere conto dei punti di vista di tutte le partiinteressate e di conciliare ogni aspetto conflittuale, per rappresentare il reale statodell’arte della materia ed il necessario grado di consenso.Chiunque ritenesse, a seguito dell’applicazione di questa norma, di poter fornire sug-gerimenti per un suo miglioramento o per un suo adeguamento ad uno stato dell’artein evoluzione è pregato di inviare i propri contributi all’UNI, Ente Nazionale Italiano diUnificazione, che li terrà in considerazione per l’eventuale revisione della norma stessa.

Le norme UNI sono revisionate, quando necessario, con la pubblicazione di nuove edizioni odi aggiornamenti.

È importante pertanto che gli utilizzatori delle stesse si accertino di essere in possessodell’ultima edizione e degli eventuali aggiornamenti.Si invitano inoltre gli utilizzatori a verificare l’esistenza di norme UNI corrispondenti allenorme EN o ISO ove citate nei riferimenti normativi.

PREMESSA NAZIONALE

La presente norma costituisce il recepimento, in lingua inglese, del-la norma europea EN 12779 (edizione dicembre 2004), che assumecosì lo status di norma nazionale italiana.

La presente norma è stata elaborata sotto la competenza della

Commissione Tecnica UNI

Sicurezza

La presente norma è stata ratificata dal Presidente dell’UNI, condelibera del 9 maggio 2005.



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EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 12779

December 2004

ICS 79.120.10

English version

Safety of woodworking machines - Chip and dust extractionsystems with fixed installation - Safety related performances and

safety requirements

Machines pour le travail du bois - Installations fixes

d'extraction de copeaux et de poussières - Performancesrelatives à la sécurité et prescriptions de sécurité

Sicherheit von Holzbearbeitungsmaschinen - Ortsfeste

Absauganlagen für Holzstaub und Späne -Sicherheitstechniche Anforderungen und Leistungen

This European Standard was approved by CEN on 20 October 2004.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O MIT É E U R O P É E N D E N O R MA L IS A T IO N

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2004 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.

Ref. No. EN 12779:2004: E



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Contents

page

Foreword..............................................................................................................................................................4

Introduction.........................................................................................................................................................5

1 Scope ......................................................................................................................................................6

2 Normative references ............................................................................................................................7

3 Terms, definitions, terminology and symbols ....................................................................................9 3.1 Terms and definitions ...........................................................................................................................9

3.2 Terminology .........................................................................................................................................12 3.3 Symbols and units...............................................................................................................................12

4 List of significant hazards ..................................................................................................................13

5 Safety requirements and/or measures ..............................................................................................14 5.1 General..................................................................................................................................................14 5.2 Controls ................................................................................................................................................14 5.2.1 General..................................................................................................................................................14 5.2.2 Safety and reliability of control systems...........................................................................................15 5.2.3 Position of and other requirements to controls ...............................................................................16 5.2.4 Mode selection.....................................................................................................................................17 5.2.5 Speed changing ...................................................................................................................................17 5.2.6 Failure of the power supply ................................................................................................................18 5.2.7 Failure of control circuits....................................................................................................................18 5.3 Protection against mechanical hazards ............................................................................................18 5.3.1 Stability of supports ............................................................................................................................18 5.3.2 Risk of break up during operation .....................................................................................................18 5.3.3 Tool holder and tool design................................................................................................................18 5.3.4 Braking systems ..................................................................................................................................18 5.3.5 Ejection .................................................................................................................................................18 5.3.6 Work-piece support and guides .........................................................................................................19 5.3.7 Prevention of access to moving parts...............................................................................................19 5.3.8 Automation and mechanisation .........................................................................................................19 5.3.9 Clamping devices ................................................................................................................................19 5.3.10 Multi-station machines........................................................................................................................19 5.3.11 Safety appliances.................................................................................................................................19 5.4 Protection against non-mechanical hazards ....................................................................................19

5.4.1 Fire and explosion ...............................................................................................................................19 5.4.2 Noise .....................................................................................................................................................33 5.4.3 Emission of chips, dust and gases....................................................................................................36 5.5 Electricity..............................................................................................................................................42 5.6 Ergonomics and handling...................................................................................................................42 5.6.1 Electrical controls................................................................................................................................42 5.6.2 Mechanical controls ............................................................................................................................42 5.7 Lighting.................................................................................................................................................42 5.8 Pneumatics...........................................................................................................................................42 5.9 Hydraulics.............................................................................................................................................42 5.10 Vibration ...............................................................................................................................................43 5.11 Laser .....................................................................................................................................................43 5.12 Static electricity ...................................................................................................................................43 5.13 Errors of fitting .....................................................................................................................................43 5.14 Isolation ................................................................................................................................................43



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5.15 Maintenance.........................................................................................................................................44

6 Information for use..............................................................................................................................44 6.1 General .................................................................................................................................................44 6.2

Warning ................................................................................................................................................44

6.2.1 Warning devices ..................................................................................................................................44 6.2.2 Warning signs ......................................................................................................................................44 6.3 Marking.................................................................................................................................................45 6.4 Instruction handbook..........................................................................................................................45 6.4.1 General .................................................................................................................................................45 6.4.2 Performance.........................................................................................................................................46 6.4.3 Explosion protection and safety systems ........................................................................................46 6.4.4 Information for use..............................................................................................................................47 6.4.5 Maintenance practice..........................................................................................................................47 6.4.6 Noise declaration.................................................................................................................................48

Annex A (informative) Table with corresponding terms in English, French and German......................49

Annex B (informative) Relationship between airflow, vacuum, air velocity and power

consumption ........................................................................................................................................53 Annex C (informative) Verification of performance measurement.............................................................56

Annex D (normative) Noise reduction at the design stage........................................................................58

Annex E (informative) Air velocity and extraction hood design................................................................60

Annex ZA (informative) Clauses of this document addressing essential requirements or otherprovisions of EU Directives................................................................................................................62

Bibliography......................................................................................................................................................63



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Foreword

This document (EN 12779:2004) has been prepared by Technical Committee CEN/TC 142 “Woodworkingmachines - Safety”, the secretariat of which is held by BSI.

This European Standard shall be given the status of a national standard, either by publication of an identicaltext or by endorsement, at the latest by June 2005 and conflicting national standards shall be withdrawn at thelatest by June 2005.

This document has been prepared under a mandate given to CEN by the European Commission and theEuropean Free Trade Association, and supports essential requirements of EU Directive(s).

For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document.

The European Standards produced by CEN/TC 142 are particular to woodworking machines and complimentthe relevant “A” and “B” standards on the subject of general safety (see introduction ofEN ISO 12100-1:2003 for a description of A, B and C standards).

This standard for Chip and dust extraction systems with fixed installation will be followed by a separatestandard for Semi-stationary chip and dust extraction machines.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerlandand United Kingdom.



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Introduction

This standard has been prepared to be a harmonized standard to provide one means of conforming to theEssential Health and Safety Requirements of the Machinery Directive and associated EFTA Regulations. Thisdocument is a type “C” standard as defined in EN ISO 12100-1:2003.

The machinery concerned and the extent to which hazards, hazardous situations and events covered areindicated in the scope of this document.

When provisions of this type C standard are different from those, which are stated in type A or B standards,the provisions of this type C standard take precedence over the provisions of other standards, for machinesthat have been designed and built in accordance with the provisions of this type C standard.

The requirements of this document are directed to manufacturers and their authorised representatives of chipand dust extraction systems. It is also useful for designers.

This document also includes information, which can be provided by the manufacturer to the user.



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1 Scope

This document sets out the safety related performance requirements and specifies the methods for eliminationof hazards or the measures that shall be taken to minimise hazards, which cannot be eliminated, on chip anddust extraction systems with fixed installation as defined in 3.1.1 and 3.1.2, for the purpose of this standard,hereinafter referred to as extraction system, connected to woodworking machines, designed to process solidwood, chipboard, fibreboard, plywood and also these materials where these are covered with plastic laminateor edgings. The extraction and conveying system operates pneumatically by vacuum and/or pressure between

± 0,3 bar.

This standard does not:

a) apply to fixed installations with an air flow capacity below 6 000 m3h

-1 installed indoors;

b) apply to moveable units with an air flow capacity below 6 000 m3h

-1;

c) apply to extraction equipment (e.g. extraction hoods, ducts) within a woodworking machine i.e. up toand including the outlet to which the extraction system is coupled;

d) apply to extraction systems connected to machines processing non-wood materials, such as plastic,plastic laminates, metals, glass or stone;

e) deal with the hazards from contact with or inhalation of dusts from wood coated with lacquer, plastic,aluminium and material with high additive contents or similar;

f) deal with shop fresh air supply;

g) apply to chip and dust extraction systems designed for K st values above 200 bar ms-1

;

h) apply to the silo discharge system;

i) cover the hazards related to Electromagnetic Compatibility (EMC) as required by the EMC Directive89/336/EEC dated 3-5-89.

This document deals with the interaction with the silo discharge system if any.

This document covers the hazards relevant to these machines as stated in Clause 4. document

Directive 94/9/EC concerning equipment and protective systems intended for use in potentially explosiveatmospheres can be applicable to the type of machine or equipment covered by this document.

The present standard is not intended to provide means of complying with the Essential Health and SafetyRequirements (EHSR) of Directive 94/9/EC.



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2 Normative references

The following referenced documents are indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenceddocument (including any amendments) applies.

EN 294:1992, Safety of machinery - Safety distances to prevent danger zones being reached by the upperlimbs

EN 418:1992, Safety of machinery - Emergency stop equipment, functional aspects - Principles for design

EN 953:1997, Safety of machinery - Guards - General requirements for the design and construction of fixedand movable guards

EN 954-1:1996, Safety of machinery - Safety related parts of control systems - Part 1: General principles fordesign

EN 982:1996, Safety of machinery - Safety requirements for fluid power systems and their components –Hydraulics

EN 983:1996, Safety of machinery - Safety requirements for fluid power systems and their components –Pneumatics

EN 1127-1:1997, Explosive atmospheres - Explosion prevention and protection - Part 1: Basic concepts andmethodology

EN 1366-1:1999, Fire resistance tests on service installations - Part 1: Ducts

EN 1366-2:1999, Fire resistance tests for service installations - Part 2: Fire dampers

EN 13284-1:2001, Stationary source emissions - Determination of low range mass concentration of dust - Part1: Manual gravimetric method

EN 60204-1:1997, Safety of machinery - Electrical equipment of machines - Part 1: General requirements(IEC 60204-1:1997)

EN 60529:1991, Degrees of protection provided by enclosures (IP Code) (IEC 60529:1989)

EN 60947-4-1:2001, Low-voltage switchgear and controlgear - Part 4-1: Contactors and motor-starters -Electromechanical contactors and motor-starters (IEC 60947-4-1:2000).

EN 60947-5-1:2004, Low-voltage switchgear and controlgear - Part 5-1: Control circuit devices and switchingelements - Electromechanical control circuit devices (IEC 60947-5-1:2003).

EN ISO 11202:1995, Acoustics - Noise emitted by machinery and equipment - Measurement of emissionsound pressure levels at a work station and at other specified positions - Survey method in situ (ISO

11202:1995)

EN ISO 11688-1:1998, Acoustics - Recommended practice for the design of low-noise machinery andequipment - Part 1: Planning (ISO/TR 11688-1:1995)

EN ISO 12100-1:2003, Safety of machinery - Basic concepts, general principles for design - Part 1: Basicterminology and methodology (ISO 12100-1:2003)

EN ISO 12100-2:2003, Safety of machinery - Basic concepts, general principles for design - Part 2: Technical principles and specifications (ISO 12100-2:2003)

EN ISO 14122-2:2001, Safety of machinery - Safety means of permanent access to machinery - Part 2:Working platforms and gangways (ISO 14122-2:2001)

EN ISO 14122-3:2001, Safety of machinery - Permanent means of access to machinery - Part 3: Stairs,stepladders and guard rails (ISO 14122-3:2001)



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EN ISO 14122-4:2004, Safety of machinery - Permanent means of access to machinery - Part 4: Fixedladders (ISO 14122-4:2004)

ISO 7000:2004, Graphical symbols for use on equipment - Index and synopsis

ISO 10816-1:1995, Mechanical vibration - Evaluation of machine vibration by measurements on non-rotating parts - Part 1: General guidelines

HD 22.1 S4:2002, Cables of rated voltages up to and including 450/750 V and having cross-linked insulation -Part 1: General requirements.



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3 Terms, definitions, terminology and symbols

3.1 Terms and definitions

For the purposes of this document, the terms and definitions given in EN ISO 12100-1:2003 and the followingapply.

3.1.1chip and dust extraction systemwood waste handling system including ducting, fans, filters, cyclones and storage facilities, including siloexcept its discharge system. The system is intended for conveyance, separation and storage of chips anddust from woodworking machines.

A typical example of an extraction system with fixed installation is illustrated as the shaded part of Figure 1

Figure 1 — Chip and dust extraction system



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3.1.2fixed installationextraction system which is permanently located and installed, or a moveable extraction system with air flowcapacity greater than 6 000 m

3h

-1

3.1.3chipsparticles of wood emanating from processing at woodworking machines. The particle size for chips is set toequal or greater than 0,5 mm

3.1.4dustparticles of wood emanating from processing at woodworking machines. The particle size for dust is set to lessthan 0,5 mm

3.1.5ducting

pipe-work, connecting woodworking machines to the fans and separators

3.1.6main ductduct to which branch ducts from a group of machines are connected

3.1.7fancomponent which produces the airflow for conveying chips and dust within the system

3.1.8separatordevice for separation of chips and dust from the conveying air

NOTE Filters and cyclones are examples of separators.

3.1.9silofixed installed equipment for storage of chips and dust

3.1.10binmovable equipment with a volume up to 0,5 m

3for storage of chips and dust

3.1.11containermovable equipment with a volume over 0,5 m

3 for storage of chips and dust

3.1.12silo discharge systemsystem which continually or intermittently empties chips and dust from silo/container

3.1.13emptying systemsystem which continually or intermittently removes chips and dust from the separator

3.1.14transport systemsystem to convey chips and dust from one or more separator or silo to other parts of the extraction system



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3.1.15extraction vacuumstatic vacuum in a duct connecting point of a pneumatic extraction system

3.1.16air velocityaverage velocity of the air inside a duct, calculated over the whole cross section and which allows thedetermination of the air flow rate (see Figure 2)

3.1.17capture velocityminimum air velocity that will draw the chips and dust towards the extraction hood (see Figure 2)

12

Key1 Air velocity

2 Capture velocity

Figure 2 — Air velocities

3.1.18concurrency factorratio in percent between the actual planned maximum air flow and the total air flow demand of all machinesconnected to the extraction system

3.1.19K st valueexplosive characteristic of combustible dust in air

NOTE K st values are detailed in EN 26184-1.

3.1.20dust loaded partdust loaded interior of the extraction system including ducting, silo, container, bin, separator etc. from the ductinlet connected to the wood working machine to the filter medium surface, where the air filtration is performed

3.1.21clean air partinterior of the extraction system from the filter medium surface, where the air filtration is performed, to the airoutlet

3.1.22return air

filtered air reintroduced into the working area



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3.1.23servicing levellevel on which persons stand when operating or maintaining the equipment

3.2 Terminology

List of corresponding terms in English, French and German is included in Annex A.

3.3 Symbols and units

Following symbols and units are used in this document:

Parameter Symbol Unit

Diameter D mm

Length L m

Area S m2

Volume V m3

Air velocity v ms-1

Air flow Qa m3h

-1

Pressure p Pa

Pressure differential ∆p Pa

Temperature t 0

C

Power P kW

Material flow Qm kgh-1

Kst value K st bar ms-1

Fan efficiency η %



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4 List of significant hazards

This standard deals with all the significant hazards relevant to the extraction system defined in the scope:

for significant hazards, by defining safety requirements and/or measures or by reference to relevant Bstandards;

for general, minor or secondary aspects, by reference to relevant A standards, especiallyEN ISO 12100-1.

These hazards are listed below in accordance with Annex A of EN 1050:1996 which is based onEN ISO 12100-1:2003 and EN ISO 12100-2:2003 with one additional item (7.4).

Table 1 — List of significant hazards

Number Hazard Relevant sub-clauses of thisdocument

1 Mechanical hazards caused for example by:- shape;- relative location;- mass and stability (potential energy of elements);- mass and velocity (kinetic energy of elements);- inadequacy of the mechanical strength.

Accumulation of potential energy by:- elastic elements (springs); or- liquids or gases under pressure; or- vacuum.

of the machine parts or workpieces.1.1 Crushing hazard 5.4.1.7; 5.3.71.2 Shearing hazard 5.4.1.7; 5.3.71.3 Cutting or severing hazard 5.4.1.7; 5.3.7

1.4 Entanglement hazard 5.4.1.7; 5.3.71.10 Ejection of parts (of machinery and processed

materials/workpieces)5.3.2

1.11 Loss of stability of machinery and machine parts 5.3.1; 5.101.12 Slip, trip and fall hazards in relationship with machinery

(because of their mechanical nature)5.4.1.7; 5.6.2

2 Electrical hazards caused for example by:2.1 Electrical contact (direct or indirect) 5.2.2; 5.52.2 Electrostatic phenomena 5.4.1.4; 5.12

3 Thermal hazards resulting in:3.1 Burns and scalds, by a possible contact of persons, by

flames or explosion and also by the radiation of heatsources

5.4.1

4 Hazards generated by noise resulting in:4.1 Hearing losses (deafness), or other physiological

disorders (e.g. loss of balance, loss of awareness)5.4.2; 6.4.6



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Table 1 — List of significant hazards (continued )

Number Hazard Relevant sub-clauses of thisdocument

7 Hazards generated by materials and substancesprocessed, used or exhausted by machinery for example:

7.1 Hazards resulting from contact with or inhalation ofharmful fluids, gases, mists, fumes and dust

5.4.3

7.2 Fire or explosion hazard 5.4.17.4 Suffocation and drowning 5.4.1.7

8 Hazards generated by neglecting ergonomic principles inmachine design (mismatch of machinery with humancharacteristics and abilities) caused for example by :

8.3 Neglect of use of personal protection equipment 6.4.58.6 Human error 5.15; 6.4

10 Hazards caused by failure of energy supply breakingdown of machinery parts and other functional disorders,

for example:10.1 Failure of energy supply (of energy and/or control circuits) 5.2.5; 5.810.2 Unexpected ejection of machine parts or fluids 5.3.210.3 Failure, malfunction of control systems (unexpected start

up, unexpected overrun)5.2.2

10.4 Errors of fitting 5.4.3.2.110.5 Overturn, unexpected loss of machine stability 5.3.1; 5.10

11 Hazards caused by (temporary) missing and/or incorrectlypositioned safety related measures/means for example:

11.1 All kinds of guard 5.3.7; 5.4.1.711.2 All kinds of safety related (protection) devices 5.2.211.3 Starting and stopping devices 5.2.3; 5.6.211.4 Safety signs and signals 5.4.3.1.2; 6.2; 6.311.5 All kinds of information and warning devices 6.2

11.6 Energy supply disconnection devices 5.2.2; 5.2.3; 5.1411.7 Emergency devices 5.2.2; 5.2.3.411.9 Essential equipment and accessories for safe adjusting

and/or maintaining5.15; 6.4.5

5 Safety requirements and/or measures

5.1 General

The machine shall comply with the safety requirements and/or protective measures of this clause. In addition,the machine shall be designed in accordance with the principles of EN ISO 12100-1:2003 for hazards relevantbut not significant, which are not dealt with by this document (e.g. sharp edges).

For guidance in connection with risk reduction by design, see Clause 4 of EN ISO 12100-2:2003 and forsafeguarding measures see Clause 5 of EN ISO 12100-2:2003.

5.2 Controls

5.2.1 General

For the purpose of this standard all electrical equipment shall comply with the requirements ofEN 60204-1:1997, and in addition:



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5.2.2 Safety and reliability of control systems

For the purpose of this standard a safety related control system means the system controlling the extractionsystem from and including automatic blast gate(s) with detector(s) in the feeding system to the connected

woodworking machine(s) if any are present, to the silo filling system including the final level switch in the silo.

The safety related control systems of this machine are those for:

emergency stopping (see 5.2.3.4);

interlocking (see 5.3.7 and 5.4.1.7);

fire detection (see 5.4.1.5);

starting (see 5.2.3.2);

normal stopping (see 5.2.3.3);

sequence interlocking (see 5.2.3.2, 5.2.3.3 and 5.2.3.4);

indication of extraction vacuum (see 5.4.3.1.2);

return air monitoring (see 5.4.3.2.2);

detection of pressure difference in separators (5.4.3.1.2);

detection of the emptying system function;

detection of silo/container filling.

The control systems for emergency stopping and for interlocking shall as minimum be Category 1 inaccordance with the requirements of EN 954-1:1996 and shall be “hardwired”.

The other control systems can be equipped with an electronic system.

Well-tried components and principles for the purpose of this standard are:

a) electrical components if they comply with relevant standards including the following as:

1) EN 60947-5-1:2004 (Section 3) for control switches with positive opening operation used asmechanically actuated position detectors for interlocking of guards and for relays used in auxiliarycircuits;

2) EN 60947-4-1:2001 for electromechanical contactors and motor starters used in main circuits;

3) HD 22.1 S4:2002 for rubber insulated cables;

4) HD 21.1 S4:2002 for polyvinyl chloride cable if these cables are additionally protected againstmechanical damage by positioning (e.g. inside frames).

b) electrical principles if they comply with measures listed from first to fourth paragraph in 9.4.2.1ofEN 60204-1:1997. The circuits shall be "hardwired“. Electronic components alone do not satisfy the “well-tried" requirements;

c) mechanical components if, for example, they operate in the positive mode in accordance with thedescription given in 4.5 of EN ISO 12100-2:2003;

d) mechanically actuated position detectors for guards if they are actuated in positive mode and theirarrangement/fastening and the cam design/mounting comply with the requirements of 5.2 and 5.3 of EN1088:1995;

e) interlocking devices with guard locking if they satisfy the requirements described in 5.3.7;

f) pneumatic and hydraulic components and systems if they comply with the requirements ofEN 983:1996 and EN 982:1996 respectively;

g) detectors and indicators if they comply with the requirements of Category B of EN 954-1:1996;

h) time delay relays if they comply with the requirements of Category B of EN 954-1:1996 and aredesigned for 1 million operations.

The control systems including detectors, indicators and time delay relays (5.2.2 g) and 5.2.2 h)) shall as aminimum be of Category B in accordance with the requirements of EN 954-1:1996.

For the purpose of this standard Programmable Logic Controllers (PLC) are considered as Category B.



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Verification : By visual inspection of the extraction system and by checking the relevant drawings and/or circuitdiagrams. For any components by requiring confirmation from the manufacturer of the component whichconforms to the relevant standards.

5.2.3 Position of and other requirements to controls

5.2.3.1 General

All electrical controls shall be placed at a minimum height of 600 mm and a maximum height of 1 800 mmfrom the servicing level.

(For the position of emergency stop controls see 5.2.3.4).

Verification: By visual inspection and measurement on the extraction system.

5.2.3.2 Starting

The starting conditions shall comply with the requirements in 9.2.5.2 of EN 60204-1:1997 (also see 6.4.4).

For extraction systems with an automatic emptying system, the starting sequence shall ensure that theemptying system is running prior to starting the extraction system.

NOTE For example the transport system between a filter and silo shall run normally before the extraction systemconnected to the woodworking machine is started.

After the emergency stop has been activated and reset, the extraction system shall perform a sequence thatbrings it to a point where a normal start up can be performed.

Verification: By visual inspection, checking the relevant diagrams and functional testing on the extractionsystem.

5.2.3.3 Normal stopping

The extraction system shall be fitted with a system stop control which, when actuated, shall provide a shut-down of all components in a predetermined sequence as defined by the manufacturer (see 6.4.4).

NOTE An example of a predetermined sequence is when the filter regeneration system has stopped, the filteremptying system shall continue until it has cleaned itself.

Any individual component stop control shall at least stop all components of the extraction system prior to theindividual component in the correct sequence of operation.


5.2.3.4 Emergency stop

The emergency stop function shall be of Category 1 in accordance with the requirements of EN 60204-1:1997.

Emergency stop devices shall meet the requirements of EN 418:1992 and 9.2.5.4 and 10.7 ofEN 60204-1:1997 and shall be provided as follows:

a) on the control panel where the normal electrical controls are situated;

b) a maximum of 50 m from all electrically connected parts of the extraction system;

c) a minimum of one emergency stop in each room with electrical parts or mechanical driven partsconnected to the extraction system;

d) be directly accessible from any frequently used moveable interlocked guard (see 5.3.7) and ifnecessary any other point of access.

Examples of emergency stop location are shown in Figure 3.



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A recommendation that the extraction system is re-started, as soon as the emergency situation has beencleared, shall be included in the instruction handbook (see 6.4.4 and 5.2.3.2).

Verification: By visual inspection, checking the relevant diagrams and functional testing on the extraction

system.

5 0 m

1

2

Key1 Electrical2 Control panel

Figure 3 — Examples of emergency stop control location

5.2.4 Mode selection

If a mode selection switch is provided (e.g. for selecting between normal mode of operation and setting modeof operation for silo’s equipped with an automatic silo discharge system (see 5.4.1.7 m)) it shall be of thelockable type.

5.2.5 Speed changing

Not relevant.



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5.2.6 Failure of the power supply

Automatic re-starting of the extraction system shall be prevented (see 7.5 paragraphs 1 and 3 ofEN 60204-1:1997).

When actuating the start control after failure of the power supply, the extraction system shall, before enteringthe normal starting sequence, perform a sequence in accordance with the requirements of 5.2.3.2 that bringsthe system into a position where a normal start up can be performed.


5.2.7 Failure of control circuits

See 5.2.2.

5.3 Protection against mechanical hazards

5.3.1 Stability of supports

All parts of the extraction system support structure shall be designed so that they can carry, at the same time,the weight of the component itself (e.g. duct, fan, separator or rotary valve) and any foreseeable additionalload (e.g. the weight of unintended wood waste filled component interior (150 kgm

-3), maintenance persons

(100 kg per person), scaffoldings, reactions from internal movements, wind load, snow etc.)

Support structures for components with explosion relief shall also be able to withstand reaction forces resultingfrom the explosion blast wave.

NOTE 1 CEN/TC 305/WG 3 standards can provide helpful information (see Bibliography).

Fan supports shall be able to withstand the unbalance requirements shown in 5.10.

NOTE 2 For more information see 5.2.6 of EN ISO 12100-2:2003.

Verification: By requiring confirmation from the manufacturer of the relevant components and by calculationbased on measurements and/or technical specifications.

5.3.2 Risk of break up during operation

Fans and components (e.g. ducts, separators and rotary valves) adjacent to the fan outlet shall be designedtaking into account the stresses they are subject to (see 4.3 of EN ISO 12100-2:2003).

Verification: By requiring confirmation from the manufacturer of the relevant components and by calculationbased on measurements and/or technical specifications.

5.3.3 Tool holder and tool design

Not relevant.

5.3.4 Braking systems

Not relevant.

5.3.5 Ejection

Not relevant.



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5.3.6 Work-piece support and guides

Not relevant.

5.3.7 Prevention of access to moving parts

Powered moving elements (e.g. fan wheels, chain conveyors, rotary valves, screw conveyors and automaticblast gates) of the extraction system shall be guarded with a fixed guard.

Where an opening is provided for frequent access (e.g. for setting, adjustment or cleaning) such openingsshall be via a moveable guard interlocked with the dangerous movement of the extraction system. For thepurpose of this standard frequent is more than once per week.

Any moving component (e.g. fans and rotary valves) with a run down time greater than 10 s and guarded byan interlocking guard shall also have guard locking.

Guards shall comply with the requirements of EN 953:1997 and the safety distances in EN 294:1992.

Verification: By visual inspection of the extraction system, measurement and checking the relevant drawings.

5.3.8 Automation and mechanisation

Not relevant.

5.3.9 Clamping devices

Not relevant.

5.3.10 Multi-station machines

Not relevant

5.3.11 Safety appliances

Not relevant.

5.4 Protection against non-mechanical hazards

5.4.1 Fire and explosion

5.4.1.1 General

Extraction systems shall be located and be constructed such that sources of ignition, fire and explosion areremoved and risks caused by fire and explosion are minimised.

Extraction systems connected to woodworking machines processing only wood shall be designed with a K st

value of 200 bar ms

-1

.If the extraction system is connected to woodworking machines processing wood combined with non-woodmaterial (e.g. lacquer, laminate and aluminium) it is recommended to evaluate whether the K st value is above200 bar ms

-1. If this is the case additional safety measures may be required (e.g. fire extinguishing devices,

additional explosion relief, safety valves, added strength construction).

Verification: By checking the relevant drawings and visual inspection of the extraction system.

5.4.1.2 Location of separator, fan and silo

The separator, fan and wood waste accumulation system shall be located outdoors (outside the workingareas) or in specially designed rooms/buildings.

The separator, fan and silo shall be located in a safe or non-hazardous area.



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Verification: By visual inspection of the extraction system.

5.4.1.3 Wood waste accumulation in ducts and separators

The conveying air velocity in all parts of the ducting shall be sufficient to avoid accumulation of wood waste inthe ducts. The minimum conveying air velocity for dry wood waste shall be 20 m s-1

as an average on anhourly basis.

Inspection and cleaning of the ducting shall be made possible by means of inspection doors or easilydetachable assemblies.

Examples of access methods for the inspection and cleaning of ducts are shown in Figure 4.

Figure 4 — Examples of duct access for inspection and cleaning

Ducts, branch ducts, inspection doors, dampers, blast-gates, fire-gates etc. in ducting conveying chips anddust shall be designed in such a way that all the chips always pass through without the risk of hanging.

If a mesh or a grate that can cause hanging is necessary in the extraction system, its function shall becontrolled and a means for monitoring shall be provided (e.g. a pressure loss indicator window for visualinspection).

Separators shall be designed such that the material build-up within the filter housing is less than 200 l per1 000 m

3h

-1of air-flow-capacity.

NOTE 1 The 200 l/1 000 m3h

-1 value is made up from 2 main elements:

a) surface build-up of waste on the filter sleeves;

b) build-up of waste in the filter hopper prior to release into the transport system.

NOTE 2 The cleaning cycle normally takes place before the build up on the filter surface is greater than 15 l/m2. This

corresponds to an average thickness of 15 mm of material on the filter surface.



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Example of dust build-up is shown in Figure 5.

Verification: By visual inspection, calculations, measurements and functional testing on the extraction system.

1

15

Key1 Dust build-up

Figure 5 — Example of chip and dust build-up in a reverse air cleaned filter



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5.4.1.4 Ignition sources

Components of the extraction system shall be designed in such a way that ignition sources are not generatedby normal use and wear.

NOTE 1 Ignition sources cannot be eliminated due to the nature of the machines connected to the extraction systems.The risk of ignition sources will depend on the type of machine.

NOTE 2 For extraction systems including sanding machines, multi-blade saws etc. ignition detection and extinguishingdevices are recommended (see Figure 6).

2

1

Key1 Ignition detector2 Extinguishing device

Figure 6 — Ignition extinguishing system

Hot surfaces shall be prevented (see 6.4.2 of EN 1127-1:1997).

NOTE 3 For wood, dust is defined in this standard as:

a) dust cloud minimum ignition temperature : 400 ºC;

b) dust layer minimum ignition temperature : 300 ºC.

Where, due to their function, parts made of steel, due to their function, operate under conditions where thereis a risk of spark generation (e.g. through contact, sliding, meshing or rubbing), one of the parts shall be

covered with copper or similar material in order to minimize the risk of sparks (e.g. fans positioned in the dustloaded part of the extraction system with less than a 20 mm gap between the inlet ducting and fan wheel (seeFigure 7)).



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1

1

A

A

D

+ 0

- x

D 1

+ 0

- x

20

2020

Key1 Copper protection ring between two steel parts

Figure 7 — Fan spark protection

Extraction systems shall be earthed.

Support cages and support rings for filtering elements shall be earthed in order to lead any charge to groundpotential.

Extraction system ductingshall be made of conductive material. In order to control discharge of staticelectricity the complete system shall have no potential difference between its individual parts.

Flexible hoses shall be able to lead charge to ground potential (see Figure 8).

Hose lengths greater than 0,5 m are only permitted when movement of the woodworking machine, to whichthe extraction system is connected makes it necessary.



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0 ,5

Figure 8 — Earthling of flexible hoses

Electrical components placed inside the system, in either the dust loaded or clean air sections, shall complywith the requirements for dust environments and explosion risk (see EN 1127-1:1997).

NOTE 4

a) Zone 20 : Dust loaded part of separator, transport system between separator and silo, and the silo;

b) Zone 21 : Duct system between the woodworking machine and separator;

c) Zone 22 : Clean air part.

Verification: By visual inspection, checking the relevant drawings, requiring confirmation from themanufacturer of the relevant components, and by measurement on the extraction system.

5.4.1.5 Damage control in the event of explosion/fire

Explosion protection of separators, silos and containers shall be in accordance with the requirements of6.5.1.3 of EN 1127-1:1997.

The blast wave expelled from explosion relief elements shall vent to a safe place (e.g. outdoor atmosphereand away from work areas and gangways with open access).

The spread of any explosion through connecting ducts shall be obstructed.

NOTE 1 Examples of obstructing components are back pressure flaps, rotary valves and de-coupling devices.



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Also see 6.5.5.3 of EN 1127-1:1997.

Examples of components for damage control are shown in Figure 9.

2

15

43

1

2

Key1 Explosion relief element2 Explosion de-coupling element3 Fire gate4 Return air5 Exhaust air

Figure 9 — Prevention of explosion transmission damage

The spread of fire through return air ducts shall be obstructed (e.g. by installing a fire gate with a temperaturesensor which activates and stops the extraction system at temperatures exceeding 70 ºC).

The ducting from one fire zone shall either:

a) not pass through another; or

b) be equipped with fire gates of an appropriate class, suitable for material transporting ducts; or

c) be insulated in accordance with the requirements of EN 1366-1:1999 and EN 1366-2:1999, level inrelation to the fire protecting wall in the subsequent fire zones.

The fire gate shall be of an appropriate class in relation to the fire protecting wall.



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An example of a section of ducting in a fire zone is shown in Figure 10.

21

4

3

1

3

Key1 Fire gate2 Fire protecting wall3 Explosion de-coupling element4 Insulation

Figure 10 — Section of ducting within a fire zone

NOTE 2 The position of the separator and the silo in relation to the buildings has a great impact on the risk of a firespreading. The greater the separation distance the less the risk.

The type of building surface (e.g. burnable/non burnable, openings/no openings) also has a great impact onthe risk of a fire spreading. Non burnable walls and roofs, without openings, are safest.

Verification: By visual inspection, checking the relevant drawings and requiring confirmation from themanufacturer of the relevant components.



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5.4.1.6 Fire fighting

All filters and silos shall, as a minimum, have a dry sprinkler system installed with an attachment for coupling itto a water supply at level of 0,4 m to 0,8 m above ground and a minimum of 5 m away.

The sprinkler system(s) specification shall be defined by agreement between the extraction systemmanufacturer and the user.

The extraction system manufacturer shall specify the sprinkler system water consumption and water pressure(see 6.4).

Examples of dry sprinkler systems are shown in Figures 11 and 12.

Dimensions in metres

3

2

1

5m

0.4-0.8m

Key1 Coupling for water supply2 Nozzles3 Hand valve

Figure 11 — Dry sprinkler system for a filter



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Dimensions in metres

2

1

5m

0.4-0.8m

Key1 Water pipe2 Nozzles

Figure 12 — Silo dry sprinkler system

Verification: By visual inspection of the extraction system and checking the relevant drawings.



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5.4.1.7 Silos

Safety requirements and/or measures are as follows:

a) the silo shall be free standing and positioned outdoors;

b) the bottom of the silo, on which the chips and dust are stored, shall be above ground level;

c) the cross-section of the silo shall either remain constant or decrease with height. The interior walls ofsilo shall be smooth and free from ledges, corners and projecting parts onto which the deposition of chipsand dust could occur;

NOTE 1 Concrete surfaces and round screw-heads are acceptable.

d) the silo filling system and the opening for feeding the silo shall be designed in such a way that thechips an dust are distributed evenly in the silo;

e) the silo shall have openings for the manual discharge of chips and dust. The minimum size of suchopenings shall be 1,2 m wide and 2,0 m high. The openings shall be on the same level as the bottomof the silo (i.e. threshold maximum 100 mm and with sloping-bottom) see Figures 13 and 14;

5m

5 m

7 m

50 ˚

6 m

8 m

4m

7m

Figure 13 — Position of silo openings (horizontal cross section)



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f) the number of openings required in the silo is as shown in Table 1. The required openings are to beplaced in the front face of the silo and shall lead directly outdoors. If the dimensions of the silomeasured in the direction of the discharge opening is greater than 6 meters, the same number ofopenings are required in the opposite face of the silo;

Examples for the arrangement of openings are shown in Figure 13.

Table 2 — Silo size and number of openings

Silo cross section Inside width/inside diameter Openingsrequired

Square/rectangular up to 4,0 m 1

above 4,0 m up to 6,5 m 2


above 8,5 m 4

Round up to 5,0 m 1


above 7,5 m 4

g) where the filling height exceeds 6 m, apertures are required in the silo through which long poles forprobing can be introduced in the same direction as the discharge openings. The apertures shall beplaced directly above the discharge openings (see Figure 14) and at least 1 m above the standingsurface. Where the filling height exceeds 9 m, additional apertures are required. The vertical distancebetween such apertures shall be a maximum of 6 m;

h) the size of the aperture required is related to the silo wall thickness. An aperture of 0,8 m × 0,8 m isrecommended for concrete silos. A steel silo can have a smaller opening;



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1 m

1 0 0 m m

2

3

5

4

1

Key1 Opening for probing in the silo ceiling

2 Opening for probing in the silo wall3 Discharge door4 Maximum filling height

5 0,5 × D (minimum 3,5 m/maximum 6,0 m)

Figure 14 — Silo apertures

i) the discharge openings and probing apertures shall be equipped with lockable doors (e.g. by padlock),which open outwards (in the direction of discharge);

j) probing apertures shall be designed so that it is impossible for the operator to enter the silo throughthem (e.g. by its size or by installing bars) (also see EN 294:1992);

k) to reduce the material pressure on the doors and protect personnel when emptying the silo by hand,

blinds shall be installed in the door openings. The blinds shall cover the full door opening and shall



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consist of elements arranged in accordance with the requirements of Figure 15. A warning sign,clearly visible from the operators position, shall indicate the hazards related to emptying the silo byhand (see 6.2.2);

l) in front of the probing apertures and discharge doors which are located higher than 1 m above ground,working platforms shall be provided (see Figures 14 and 15). The platforms shall meet therequirements of EN ISO 14122-2:2001 and EN ISO 14122-3:2001;

m) platforms shall be easily accessible by means of stairs or stepladders in accordance with therequirements of EN ISO 14122-3:2001 with a warning at the entrance (see 6.2.2);

n) fixed ladders shall meet the requirements of EN ISO 14122-4.

Key1 Door handle with padlock

Figure 15 — Silo opening details

o) where the silo is equipped with an automatic discharge system (e.g. a rotating screw conveyor) theaccess door(s) shall be interlocked with the automatic discharge system and the run-down time shallbe less than 10 s;

p) for maintenance purposes it shall be possible to run the automatic discharge system with the door(s)in the open position. Therefore the automatic discharge system shall have a mode selection switch,situated on the control panel, for selecting either normal mode or setting mode. In setting mode anydangerous movement of the silo discharge system shall only be possible when the followingrequirements are met:

1) the movements shall be controlled by hold to run controls. An emergency stop shall be provided

which can be actuated from the silo point of access;



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2) hold to run controls shall be located outside the silo, but the operator shall have an unrestrictedview over the movements being initiated.

NOTE 2 Silo surface materials, distances etc. may be subject to national regulations.

Verification: By visual inspection, checking the relevant drawings and by measurement on the extractionsystem.

5.4.2 Noise

5.4.2.1 Noise reduction at the design stage

When designing chip and dust extraction systems the information and technical measures to control noise atsource given in EN ISO 11688-1:1998 shall be taken into account.

NOTE The main noise sources and measures to reduce noise of chip and dust extraction systems are given innormative Annex D.

Verification: By visual inspection of the extraction system and checking the relevant drawings.

5.4.2.2 Noise emission measurement

5.4.2.2.1 General

Noise measurements shall be performed at the extraction system user’s premises for the following reasons:

a) extraction systems are large machines;

b) noise sources are distributed along the machine with long ducting arrangements often located at ahigh level;

c) noise sources are located in different places;

d) accurate noise measurement at the manufacturer’s premises is impossible as the site at which theextraction system is installed greatly influences the noise levels measured.

It shall be noted that noise levels measured in accordance with the following method are influenced by theconfiguration of the site at which the chip and dust extraction system is installed, by the type of chip and dustcollection hood(s) used and the type of machine(s) attached to the extraction system.

5.4.2.2.2 Operating conditions

During the noise test the extraction system shall be operating with the air velocity and the staticpressure/vacuum described in the extraction system specification. If more than one combination of the

extraction system operating conditions are specified, a noise test shall be performed for the designedcombinations with maximum airflow.

The noise measurements shall be performed on an extraction system installation with woodworking machinescoupled to the extraction system at the appropriate places.

All woodworking machines shall be turned off during the noise measurements, i.e. the extraction system willbe operating without chips and dust.

NOTE For the purpose of this standard only operation without chips and dust is prescribed. According to theguidelines for preparation of noise test codes operation with chips and dust should also have been included: however nosuitable specification of the chips and dust content is available for this purpose.



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1 . 6 m

1 . 6 m

1 . 6 m

1 m

1m

1m

1m

2m

Figure 16 — Microphone position locations

The microphone positions shall be:

a) for components meeting the requirements of 5.4.2.2.5 a) and 5.4.2.2.5 b) at 1,6 m from ground underthe axis of each duct line and minimum of 1 m from the component; and

b) for components meeting the requirements of 5.4.2.2.5 c) and 5.4.2.2.5 d) at 1,6 m from ground and at1m from the reference surface enclosing the components.

The extraction hood does not constitute part of the extraction system and its influence on the measured sound

pressure level shall be minimised by performing measurements at least 2 m away from the connectedmachine(s) (also see 5.4.2.2.3).

The instrumentation used shall be of Class 1 and shall further conform to the requirements given in Clause 5of EN ISO 11202:1995.

In cases with fluctuating noise or periodic impulse noise, the time-averaged A-weighted sound pressure soundpressure level, LpAeq, shall be measured instead of the maximum A-weighted sound pressure level withS-weighting. In the latter case, the measurement shall be made over a period of at least 5 min, including atleast one cycle (e.g. cleaning cycle). The number of cycles shall be declared. In addition, for cases withperiodic impulse noise, the peak C-weighted sound pressure level, LpCpeak, shall be measured.

The measurement method consists of the following:

c) measure the maximum A-weighted sound pressure levels, LpAS, (or, if appropriate, the peakC-weighted sound pressure levels, LpCpeak, and the time-averaged A-weighted sound pressure levels,LpAeq) for each of the four groups of components shown in 5.4.2.2.5 when the extraction system is inoperation under conditions given in 5.4.2.2.2;

d) measure the background noise level (A-weighted or C-weighted, as appropriate) when the extractionsystem is stopped, at the same measurement points;

e) correct the measured sound pressure level(s) when the extraction system is in operation forbackground noise, in accordance with the requirements of 5.4.2.2.3;

f) record and describe the acoustic environment at the test site;

g) report the corrected sound pressure levels in accordance with steps a) to d).



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5.4.2.2.6 Test report

Test report shall contain the following:

a) identification of the extraction system under test;

b) reference to this standard;

c) extraction system operating conditions used during the test;

d) measured noise values for each part of the system together with the location of the measurementpositions;

e) correction values;

f) description of the acoustic environment.

Verification: By checking the test report.

5.4.3 Emission of chips, dust and gases

Emission of chips and dust resulting from wood processing is generated by the woodworking machine(s).

The extraction system controls the emission of chips and dust from the woodworking machines, extractionhoods etc. connected to it..

This standard covers the performance requirements of the extraction system based on specifications for thewoodworking machines connected to it.

Emission of chips and dust from the extraction system is caused by leakage and incomplete filtration of returnair.

NOTE 1 Emission caused by incomplete capturing of chips and dust by the woodworking machines, extraction hoodsetc. is covered by the relevant machine standard.

Recommendations for the design of extraction hoods are given in Annex E.

NOTE 2 If gases are created in the working area they will be partially removed from the working area by the chips- anddust extraction system. However, these gases will not be filtered by the chip and dust separation process

NOTE 3 The ratio between the fresh air supply and return air may have to comply with local regulations on airexchange air quality.

5.4.3.1 Performance requirements

5.4.3.1.1 Plant design

The extraction system shall be designed taking account of:

a) the number and type of machines to be connected to it, their concurrency in use and the layout of theworkshop or factory (information to be supplied by the user);

b) the machine manufacturer’s information or an experienced body’s information on required therequired air flow and extraction vacuum for each extraction connection for each machine.

Examples of extraction system design calculation are given in Table 3.



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Table 3 — Example of extraction system design calculation

Air flow Combination A Combination BMachinetype m

3h

-1 On/Off m

3h

-1 On/Off m

3h

-1

Moulder 10 000 On 10 000 Off 0Saw 2 500 On 2 500 On 2 500

Band saw 3 200 Off 0 On 3 200

Planer 6 000 Off 0 On 6 000

Total 21 700 12 500 11 700

In the example shown in Table 3, the four machines can operate either in combination A or combination B. As12 500 m

3h

-1 is larger than 11 700 m

3h

-1, the design air flow for the extraction system is then 12 500 m

3h

-1.

The plant design shall ensure that all machines operating under the specified working conditions will have asa minimum the indicated airflow and extraction vacuum. The specified performance shall be achieved after arunning-in period and stabilization of the pressure difference at filter units etc. and must be verified throughmeasurement in accordance with the requirements of 5.4.3.1.3.

An example of the relationship between airflow, extraction vacuum, air velocity and power consumption isshown in Annex B.

Verification: By checking the relevant drawings and by calculation based on measurements and/or technicalspecifications.

5.4.3.1.2 Performance indication

An indicator shall be provided at each main duct to demonstrate that the specified extraction requirement(e.g. vacuum) is achieved. It may be combined with a visual alarm activated when the actual performance isoutside the preset area.

An example of the location of a performance indicator is shown in Figure 17.




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21

Key1 Indicator 2 Alarm panel

Figure 17 — Performance indicator

5.4.3.1.3 Airflow measurement

Ducting shall be designed at each machine in such a way that airflow can be measured by a flow instrument(e.g. Pitot gauge)

NOTE An example of compliance with requirement is a duct, diameter D, with its linear part having a minimum lengthof 8 x D. A linear length of 5 x D is required before the measuring point and a linear length of 3 x D is required after the

measuring point.

Example of ducting design with a measuring point is shown in Figure 18.



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5 x d

d

3 x d

Figure 18 — Example of duct measuring point location

Airflow and extraction vacuum shall be measured and reported in the documentation after the running-inperiod and stabilization of pressure difference at the filter units etc. (see 6.4.2.1).

An example of a test report is given in Annex C.

Airflow and extraction vacuum measurements shall be made at each connected machine outlet and for the

planned combination of machines to be used concurrently.

Documentation of the measurements required in this clause shall be provided by the extraction systemmanufacturer.

Verification: By visual inspection of the extraction system and checking the test report.

5.4.3.2 Emission of dust

5.4.3.2.1 Leakage

Ducting placed inside the working area shall operate at pressures below atmospheric.

NOTE Leakage can be caused by defects in the components of the extraction system, inadequate mounting and/orassembly during installation, pressure and/or mechanical overload on components and/or assemblies, wear and/orcorrosion defects, back-flow in the ducting during or after cleaning, inadequate maintenance (e.g. inaccurate detection andrepair of wear and/or corrosion defects).

An example of a duct system with under pressure is shown in Figure 19.

Verification: By visual inspection, checking the relevant drawings and by measurement on the extractionsystem.



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1

2 3

Key

1 Duct with under pressure2 Indoors3 Outdoors

Figure 19 — Duct with under pressure inside the working area



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5.4.3.2.2 Residual dust in separator outlet/return air

When return air is used (depending on national regulations) the requirements of this clause shall be fulfilled.

The residual dust content in the return air shall be lower than 0,2 mgm -3 as a weighted average and allindividual outlets shall have a dust content lower than 0,3 mgm

-3.

NOTE 1 The requirement on dust concentration in return air is a system design figure. It is not to be seen as a limitvalue for the working place.

NOTE 2 Residual dust content in the outlet air from the separator in the extraction system (e.g. a filter) can arise frome.g. incomplete filtration of the air going through the filtration element, leakage in the filter housing and the fixation of thefilter material.

Often the sources of residual dust cannot be separated.

From the extraction system commissioning date, the residual dust content concentration in the return air shallhave achieved the values shown in this clause within 4 weeks.

NOTE 3 This is to allow the filter cake to develop to a stable level.

When the cleaned air is returned to the working area, the dust content in extraction systems with an air flowcapacity larger than 10 000 m

3h

-1 shall be monitored continuously (e.g. by electrical dust alarm, air filter with

pressure sensor, etc.).

When the residual dust content exceeds 0,3 mgm-3

the return air shall be diverted to the outdoor atmosphereand an alarm shall be given or the extraction system shall stop.

NOTE 4 The primary cause of dust content in the working area is the inability of the extraction hood to capture all thegenerated dust and the re-entrainment of dust from dust covered surfaces (e.g. floor, products, machine cleaning). One ofthe worst examples of dust re-entrainment is when cleaning is achieved by blowing with pressurised air (a vacuum cleaner

should be used). The residual dust content in return air will only have a minor influence on the dust concentration in theworking area.

The measurement of the residual dust content shall be made in accordance with the requirements ofEN 13284-1:2001 and shall be carried out within 4 weeks of the commissioning date.

Operating conditions during the measurement shall be such that:

a) the air flow rate shall be at its maximum design level;

b) the dust load shall correspond to the production parameters for which the extraction system isdesigned;

c) the extraction system shall be operating with all features functioning as designed (e.g. cleaning

system, emptying system).

The residual dust content in the extraction system outlets to the outdoor atmosphere is not covered by thisstandard.




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5.5 Electricity

The requirements in Clause 6 of EN 60204-1:1997 regarding the prevention of electric shock and Clause 7 ofEN 60204-1:1997 for protection against short circuits and for protection against overloading shall apply.

The degree of protection of components situated in Zone 20, 21 or 22 (see 5.4.1.5) shall comply with therequirements of EN 1127-1:1997.

All other electrical components shall be of a minimum IP54 in accordance with the requirements ofEN 60529:1991.

Verification: By checking the relevant diagrams and requiring confirmation from the manufacturer of therelevant components.

5.6 Ergonomics and handling

5.6.1 Electrical controls

See 5.2.3 and 5.2.3.2 to 5.2.3.4.

5.6.2 Mechanical controls

Mechanical controls activated more frequently than once per week (e.g. several times per month) shall bepositioned at a maximum height of 1 800 mm from the servicing level.

Controls, dampers etc. which are to be rarely used (e.g. 4 times a year) shall be placed in positions where it ispossible to establish access.

Also see 6.4.


5.7 Lighting

Not relevant.

5.8 Pneumatics

Pneumatic components of the extraction system shall meet the requirements of EN 983:1996.

Verification: By requiring confirmation from the manufacturer of the relevant components.

5.9 Hydraulics

Not relevant.



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5.10 Vibration

Vibration can cause fatigue stress damage (e.g. on support structures).

Vibrating components of the extraction system shall be tested in accordance with the requirements ofISO 10816-1:1995 with measuring points in accordance with the requirements of 3.2 of ISO 10816-1:1995(first section) and the test support structure in accordance with the requirements of 3.3.2 of ISO 10816-1:1995.

NOTE 1 The test can be carried out by the manufacturer.

The vibration velocity shall be declared and stated in the technical documentation for the component.

NOTE 2 Values for the vibration velocity for the fan depend on and are influenced by e.g. fan rotational speed, fan restbalance, support structure design, fan mass. Practical experience indicates that the vibration velocity can be expected tobe between 5 mms

-1to 18 mms

-1.

Foundation and fixation of vibrating components shall be designed in accordance with normal design practiseand the calculations shall be based on the component weight and the vibration velocity normally expected.

NOTE 3 Flexible connections and supports with vibration dampers will normally lower vibration transmission.


5.11 Laser

Not relevant.

5.12 Static electricity

See 5.4.1.4.

5.13 Errors of fitting

Removable parts (e.g. fan, chain conveyor, rotary valves, screw conveyor, automatic blast gates) shall bedesigned such that that their assembly to or removal from the extraction system (e.g. maintenance and/orrepair) does not lead to hazardous situations arising. Information regarding the removable parts shall be given(e.g. direction of movement or rotation).

5.14 Isolation

Electrical isolators shall be in accordance with the requirements of 5.3 of EN 60204-1:1997.

It shall be possible to isolate the pneumatic energy supply (e.g. a lockable valve). For means of isolation see

EN 983:1996.

Where residual energy is stored (e.g. compressed air in a reservoir or pipe), a means for dumping residualpressure shall be provided (e.g. a valve).

Verification: By visual inspection, checking the relevant diagrams and requiring confirmation from themanufacturer of the relevant components.



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EN 12478:2003

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Transcript of EN 12478:2003