SIST EN 894-3:2002+A1:2008

Safety of machinery - Ergonomics requirements for the design of displays and control actuators - Part 3: Control actuators

This European Standard gives guidance on the selection, design and location of control actuators so that they are adapted to the requirements of the operators, are suitable for the control task in question and take account of the circumstances of their use.
It applies to manual control actuators used in equipment for occupational and private use. It is particularly important to observe the recommendations in this European Standard where operating a control actuator may lead to injury or damage to health, either directly or as a result of a human error.

Sicherheit von Maschinen - Ergonomische Anforderungen an die Gestaltung von Anzeigen und Stellteilen - Teil 3: Stellteile

Diese Europäische Norm enthält Empfehlungen über die Auswahl, Gestaltung und Anordnung von Stellteilen, um eine Anpassung an die Anforderungen des Operators, die Eignung für die in Frage kommenden Steuerungsaufgaben und die Einsatzbedingungen zu berücksichtigen.
Sie gilt für handbetätigte Stellteile an Arbeitsmitteln für gewerbliche und private Zwecke. Es ist besonders wichtig, die Empfehlungen dieser Europäischen Norm zu berücksichtigen, wenn die Betätigung eines Stellteils entweder direkt oder aufgrund eines menschlichen Fehlverhaltens zu Verletzungen oder gesundheitlichen Schäden führen kann.

Sécurité des machines - Exigences ergonomiques pour la conception des dispositifs de signalisation et des organes de service - Partie 3: Organes de service

La présente norme européenne donne des recommandations sur la sélection, la conception et l’emplacement des
organes de service de telle sorte qu’ils soient adaptés aux exigences des opérateurs et qu’ils conviennent à la tâche
impliquant la commande concernée en tenant compte de leurs conditions d’utilisation.
Elle s’applique aux organes de service manuels utilisés avec les équipements à usage professionnel et privé.
Le respect des recommandations de la présente norme européenne est particulièrement important lorsque
l’utilisation d’un organe de service peut induire des risques en matière de santé et de sécurité, soit directement,
soit suite à une erreur humaine.

Varnost strojev - Ergonomske zahteve za načrtovanje prikazovalnikov in krmilnih stikal - 3. del: Krmilna stikala

General Information

• Status: Published
• Publication Date: 03-Nov-2008
• ICS: 13.110 - Safety of machinery
• ICS: 13.180 - Ergonomics
• Technical Committee: VSN - Safety of machinery
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 30-Oct-2008
• Due Date: 04-Jan-2009
• Completion Date: 04-Nov-2008
• Directive: 2006/42/EC - Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)
• Directive: 98/37/EC - Machinery
• Directive: EUR-PUB - European Union - Public Standards
• Mandate: M/079 - Mandate to CEN and CENELEC for standardization in the field of machines
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Ref Project: EN 894-3:2000+A1:2008 - Safety of machinery - Ergonomics requirements for the design of displays and control actuators - Part 3: Control actuators

Relations

• Consolidates: SIST EN 894-3:2002 - Safety of machinery - Ergonomics requirements for the design of displays and control actuators - Part 3: Control actuators
• Effective Date: 01-Dec-2008

Overview

EN 894-3:2000+A1:2008 - Safety of machinery: Ergonomics requirements for the design of displays and control actuators - Part 3: Control actuators (CEN) provides practical guidance for the selection, design and positioning of manual control actuators so they match operator capabilities, task demands and use environments. It applies to equipment for occupational and private use and is especially relevant where control actuation could directly or indirectly cause injury or health damage due to human error.

Key topics and requirements

• Selection procedure (iterative, three steps):
  • Task evaluation and information collection
  • Intermediate selection of control families
  • Identification of suitable control types
• Task requirement classification (five-level scale 0–4) for:
  • Accuracy, speed, force
  • Visual check, tactile check, inadvertent operation prevention
  • Friction / anti-slip, use with gloves, ease of cleaning
• Movement characteristics to consider:
  • Type (linear vs rotary), axis and direction of movement, continuity (discrete vs continuous), angle of rotation (>180°)
• Grip characteristics:
  • Type of grip (contact, pinch, clench), part of hand (finger vs whole hand), method of force application (normal vs tangential)
• Human factors guidance:
  • Feedback requirements for discrete vs continuous controls
  • Trade-offs (e.g., high accuracy vs high force)
  • Recommendations on discrete position limits (note: >24 positions considered high and should generally be avoided)
  • Labelling and feedback: prefer descriptive labels and visual/tactile cues over cryptic numbering; follow EN 894‑2 for displays
• Normative references and alignment with EU Directives (annexes link the standard to essential requirements)

Practical applications and users

Who should use EN 894-3:

• Machine designers and product engineers selecting control actuators for machinery and equipment
• Ergonomists and human-machine interface (HMI) specialists
• Safety engineers and risk assessment teams implementing EN 1050/CE compliance
• Manufacturers of control panels, industrial machinery, consumer equipment
• Maintenance and operations planners specifying usable, safe control layouts

Typical uses:

• Choosing actuator types (push-buttons, knobs, hand wheels) for specific tasks
• Designing control layouts that minimize error, slips and inadvertent operation
• Specifying controls for gloved operation, hygienic cleaning, or high-speed emergency actuation
• Documenting selection rationale during design reviews and conformity assessment

Related standards

• EN 894-1, EN 894-2 (displays & general principles)
• EN 292-1 / EN 292-2 (machinery safety fundamentals)
• EN 574 (two-hand controls), EN 614-1 (ergonomic design principles)
• prEN 1005-3 (human strength limits), EN 1050 (risk assessment)
• ISO 447, IEC 60447 (control direction/actuating principles)

Keywords: EN 894-3:2000+A1:2008, control actuators, ergonomics, safety of machinery, manual control actuators, human-machine interface, selection procedure, operator ergonomics, CEN.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Sicherheit von Maschinen - Ergonomische Anforderungen an die Gestaltung von Anzeigen und Stellteilen - Teil 3: StellteileSécurité des machines - Exigences ergonomiques pour la conception des dispositifs de signalisation et des organes de service - Partie 3: Organes de serviceSafety of machinery - Ergonomics requirements for the design of displays and control actuators - Part 3: Control actuators13.180ErgonomijaErgonomics13.110Varnost strojevSafety of machineryICS:Ta slovenski standard je istoveten z:EN 894-3:2000+A1:2008SIST EN 894-3:2002+A1:2008en,fr01-december-2008SIST EN 894-3:2002+A1:2008SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 894-3:2000+A1
October 2008 ICS 13.100; 13.180 Supersedes EN 894-3:2000 English Version
Safety of machinery -Ergonomics requirements for the design of displays and control actuators - Part 3: Control actuators
Sécurité des machines - Exigences ergonomiques pour la conception des dispositifs de signalisation et des organes de service - Partie 3: Organes de service
Sicherheit von Maschinen - Ergonomische Anforderungen an die Gestaltung von Anzeigen und Stellteilen - Teil 3: Stellteile This European Standard was approved by CEN on 3 February 2000 and includes Amendment 1 approved by CEN on 14 August 2008.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36
B-1050 Brussels © 2008 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 894-3:2000+A1:2008: ESIST EN 894-3:2002+A1:2008

Example of the use of this standard.35 Annex ZA (informative)
!!!!Relationship between this European Standard and the Essential Requirements of EU Directive 98/37/EC, amended by 98/79/EC"""".39 Annex ZB (informative)
!!!!Relationship between this European Standard and the Essential Requirements of EU Directive 2006/42/EC"""".40
Figure 1 — Overall selection process for manual control actuators
Negligible
Low
Average
High
Very high
The task requirements do not need to be evaluated precisely, therefore the detailed evaluation procedure given in 5.2 and 5.3, show classification systems that have been found to be sufficiently accurate. The characteristics of the various types of control actuator need to be considered to determine the available selection options. This standard gives information on both movement characteristics and grip characteristics. In many cases some of the characteristics will have been predetermined by the task requirements. Movement characteristics: j) Type of movement; k) Axis of movement; l) Direction of movement; m) Continuity of movement; n) Angle of rotation for continuous rotary movements > 180° Grip characteristics: o) Type of grip; p) Part of hand applying force; q) Method of applying force. The above categories a - q are used throughout this standard. The shorter descriptions given in brackets after the full descriptions are used in table headings where space is limited.
0 1 2 3 4
General Task Requirements 5.2
a) Accuracy 5.2.1
b) Speed 5.2.2
c) Force 5.2.3
Specific task requirements 5.3
d) Visual check 5.3.1
e) Tactile check 5.3.2
f) Inadvertent operate 5.3.3
g) Friction 5.3.4
h) Use with gloves 5.3.5
i) Ease of cleaning 5.3.6
Movement characteristics 5.4
j) Type of movement 5.4.1 Linear Rotary
k) Axis of movement
5.4.2 x y z x y z
l) Direction of movement 5.4.3 +/- +/- +/-+/-+/- +/-
m) Continuity of movement 5.4.4 Continuous Discrete
n) Angle of rotation for continuous rotary movement > 180° 5.4.5 Yes No
Grip characteristics 5.5
o) Type of grip (see fig 4) 5.5.1 ContactPinch Clench
p) Part of hand applying force 5.5.2 Finger Hand
q) Method of applying force 5.5.3 Normal Tangential
Figure 2 — Example of form for recording information used in the selection procedure for manual control actuators
Accuracy in positioning relates to the accuracy of positioning a manual control actuator itself. Accuracy in the positioning of the controlled component may be increased by mechanical means e.g. gears. In this case a high accuracy of positioning of the controlled component may be achieved by use of a manual control actuator capable of only low accuracy. 5.2.1.1 Discrete manual control actuator movements
A discrete manual control actuator movement is one where the manual control actuator can only be moved to a number of fixed positions e.g. rotary switch, on/off switch. The error in selecting the correct position increases with the number of discrete positions. Thus two positions shall be rated as "negligible" requirements whilst 24 positions shall be rated as "high" requirements. Manual control actuators with more than 24 discrete positions should be avoided. Accuracy can be improved by, for example, feedback to the operator of information on the current value of the controlled variable, by clear labelling of manual control actuator positions, by placing the manual control actuator where it can be easily seen and moved. For manual control actuators a visual indication of the function of each position should be provided either by labels or a display. Positions should not be indicated by numbers (1, 2 etc) or letters (A, B etc) to indicate a function, since this requires the operator to remember the related functions and leads to mistakes. Labels 1,2 etc. may be used where the value of the variable controlled varies from position to position at least on an ordinal scale. This becomes more important as the number of discrete positions increases. Labels and displays shall be designed in accordance with the requirements in EN 894 -2. When selecting control actuators whose functions are critical for avoiding injury or damage to health it is especially important that these requirements are followed. 5.2.1.2 Continuous manual control actuator movements Where movement of a manual control actuator corresponds to a continuous change in a controlled variable, the extent to which the variable deviates from the required value is a measure of error. The probability of making an error depends mainly on the time allowed to complete the task (speed), availability of feedback of information to the operator, and operating force. SIST EN 894-3:2002+A1:2008

The time to complete a manual control actuator movement is composed of two components: time to reach and grasp the manual control actuator and time to make the control movement. The former of these depends on the position of the manual control actuator relative to the operator and the type of grip necessary for its operation. In general, manual control actuators requiring contact grip are quicker to operate than manual control actuators requiring pinch grip which are quicker than manual control actuators requiring clench grip. For emergency situations it is essential for actuation to be as quick as possible. A mushroom shaped actuator operated by hand contact is therefore recommended for emergency stop functions on machinery. High speed of operation is inconsistent with a high force requirement, and the highest speeds can only be obtained when the force is lowest. Thus for continuous tasks, such as keyboard operation, where high speed is necessary the operating force should be kept low. The specification of high speed and high force requirement together will not lead to the successful selection of a suitable manual control actuator. 5.2.3 Task requirement c): Classification of force/torque (force) Control actuators may be used to move parts of a machine. In some circumstances large forces may be needed to move these parts. Some machine designs allow mechanical or power assistance to minimise the load on the operator when using the control actuator. Where this is not possible the magnitude of the force or torque required to operate the manual control actuator shall be assigned to one of the classes shown in table 2. The symbols in this table are used later in the evaluation process, therefore it is recommended that the appropriate symbol be recorded. Where control actuators are used frequently or for long durations force requirements are increased. Table 2 — Classification of force/torque for the selection of manual control actuators
CODE
SYMBOL
FORCE (N) OR TORQUE (N.m) DEGREE OF REQUIREMENTS 0
<10 N <0,5 N.m Negligible
>10 to <25 N >0,5 to <1,50 N.m Low 2
>25 to <50 N >1,50 to <3,0 N.m Average 3
>50 to <80 N >3,0 to <5,0 N.m High 4
>80 to <120 N >5,0 to <50 N.m Very high
In some situations where the operator's vision is fully occupied or the control actuator is located away from the operator's field of vision, it is important for the position of manual control actuators to be readily identified by touch. Identification by touch can also be useful in reinforcing other forms of information feedback to the operator where safety critical functions are involved. The need for tactile checking of the manual control actuator setting shall be assigned to one of the classes shown in table 1. 5.3.3 Task requirement f): Need to avoid inadvertent operation The importance of avoiding inadvertent operation of a manual control actuator depends on the consequences of such accidental operation. It is particularly important where injury or damage to health may result. This standard gives information on the degree of difficulty in inadvertently operating a control actuator itself. In some circumstances, where very high risks are present, this may not be considered sufficient. In such cases the following measures should be considered:  locate manual control actuator in a recess;  shroud the manual control actuator e.g. cover to prevent access of parts of body larger than the hand, surround manual control actuator with a collar;  use manual control actuators that are operated in two movements at right angles to each other;  use a lock-out system; SIST EN 894-3:2002+A1:2008
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