Bsi bs en 00418 1992 (1998)

www bzfxw com BRITISH STANDARD BS EN 418 1992 Safety of machinery — Emergency stop equipment, functional aspects — Principles for design The European Standard EN 418 1992 has the status of a British S[.]

BRITISH STANDARD BS EN

418:1992

Safety of machinery —

Emergency stop

equipment, functional

aspects —

Principles for design

The European Standard EN 418:1992 has the status of a

British Standard

UDC 62-783.5:331.45:614.8

This British Standard, having

been prepared by the

Machinery and Components

Standards Policy Committee,

was published under the

authority of the Standards

Board and comes into effect on

15 December 1992

© BSI 10-1998

The following BSI references

relate to the work on this

standard:

Committee reference MCE/3

Draft for comment 90/82130 DC

ISBN 0 580 20861 3

Cooperating organizations

The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries:

Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation

Finland Suomen Standardisoimisliito, r.y

France Association française de normalisation Germany Deutsches Institut für Normung e.V

Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland

Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut

Portugal Instituto Portuguès da Qualidade Spain Asociación Española de Normalización y Certificación Sweden Standardiseringskommissionen i Sverige

Switzerland Association suisse de normalisation United Kingdom British Standards Institution

Amendments issued since publication

BS EN 418:1992

Contents

Page

National annex NA (informative) Committees responsible Inside back cover National annex NB (informative) Cross-references Inside back cover

National foreword

This British Standard has been prepared under the direction of the Machinery and Components Standards Policy Committee and is the English language

version of EN 418 Safety of machinery — Emergency stop equipment, functional

aspects — Principles for design published by the European Committee for

Standardization (CEN) EN 418 was produced as a result of international discussions in which the United Kingdom took an active part

A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application

Compliance with a British Standard does not of itself confer immunity from legal obligations.

Summary of pages

This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 8, an inside back cover and a back cover

This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover

EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 418

October 1992

UDC 62-783.5:331.45:614.8

Descriptors: Safety of machines, dangerous machines, accident prevention, safety devices, control devices, stopping, emergency

measures, design, specifications

English version

Safety of machinery — Emergency stop equipment,

functional aspects — Principles for design

Sécurité des machines — Equipement d’arrêt

d’urgence, aspects fonctionnels — Principes

de conception

Sicherheit von Maschinen — Not-Aus-Einrichtung, funktionelle Aspekte — Gestalgungsleitsätze

This European Standard was approved by CEN on 1992-10-16 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 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 translation under the

responsibility of a CEN member into its own language and notified to the

Central Secretariat has the same status as the official versions

CEN members are the national standards bodies of Austria, Belgium,

Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,

Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and

United Kingdom

CEN

European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung

Central Secretariat: rue de Stassart 36, B-1050 Brussels

© 1992 Copyright reserved to CEN members

Ref No EN 418:1992 E

Foreword

CEN/TC 114-CLC/TC 44X/JWG 9 has been

entrusted by CEN/TC 114 with the task of

producing standards on emergency stop, safety hold,

isolation and energy dissipation

This standard is the result of the first part of this

task

The standard was accepted and in accordance with

the CEN/CENELEC Internal Regulations, the

following countries are bound to implement this

European Standard: Austria, Belgium, Denmark,

Finland, France, Germany, Greece, Iceland,

Ireland, Italy, Luxembourg, Netherlands, Norway,

Portugal, Spain, Sweden, Switzerland, and the

United Kingdom

This European Standard shall be given the status of

a national standard, either by publication of an

identical text or by endorsement, at the latest by

April 1993, and conflicting national standards shall

be withdrawn at the latest by April 1993

Contents

Page

4.2 Specific requirements for electrical

4.3 Operating conditions, environmental

4.4 Shape, colour and arrangement of

4.5 Additional requirements for wires and

Figure 1 — Functional aspects of the field of

Figure 2 — Emergency stop equipment in

EN 418:1992

0 Introduction

This European Standard has been prepared under a

mandate given to CEN by the Commission of the

European Communities and the European Free

Trade Association, and supports essential

requirements of the machinery EC Directive and

associated EFTA regulations

An essential safety requirement of the Machinery

Directive relating to emergency stopping and

reproduced in subclause 6.1.1 of EN 292-2 specifies

that machinery shall be provided with emergency

stop equipment, except for:

— machines in which an emergency stop

equipment would not lessen the risk, either

because it would not reduce the stopping time or

because it would not enable the special measures

required to deal with the risk to be taken;

— hand-held portable machines and hand-guided

machines

The purpose of this standard is to specify the functional requirements the emergency stop equipment has to comply with, to fulfil the essential safety requirements of the Machinery Directive

As a complement to this standard, a standard

dealing with the control device (see 3.3) of electrical

emergency stop equipment is being prepared by CENELEC/TC 17 B

1 Scope

This standard specifies design principles for emergency stop equipment for machinery No account is taken of the nature of the energy source

A functional demarcation of the emergency stop equipment is shown in Figure 1 Figure 2 illustrates the location of this equipment in machinery

Figure 1 — Functional aspects of the field of application of EN 418

2 Normative references

This European Standard incorporates, by dated or

undated reference, provisions from other

publications These normative references are cited

at the appropriate places in the text and the

publications are listed hereafter For dated

references, subsequent amendments to or revisions

of any of these publications apply to this European

Standard only when incorporated in it by

amendment or revision For undated references the

latest edition of the publication referred to applies

EN 292-1:1991, Safety of machinery — Basic

concepts — General principles for design —

Part 1: Basic terminology, methodology.

EN 292-2:1991, Safety of machinery — Basic

concepts — General principles for design —

Part 2: Technical principles and specifications.

EN 60204-1:1985, Electrical equipment of industrial

machines — Part 1: General requirements.

NOTE EN 60204-1:1985 has undergone a major revision and

the resulting prEN 60204-1:1991 “Safety of machinery —

Electrical equipment of machines — Part 1: General

requirements” has been adopted in February 1992 In order to

help make the transition between EN 60204-1:1985 and its new

version, every reference to a section or sub-section of

EN 60204-1:1985 in the present standard is complemented by a

reference to the equivalent part of prEN 60204-1:1991.

EN 60947-5-1:1992 (3rd part), Low-voltage

switchgear and controlgear — Part 5: Control circuit

devices and switching elements —

Chapter 1: Definitions, characteristics, tests —

Section 3: Special requirements for control switches

with positive opening operation.

3 Definitions

For the purposes of this standard, the following definitions apply

3.1 emergency stop (function)

function which is intended

— to avert arising or to reduce existing hazards to persons, damage to machinery or to work in progress;

— to be initiated by a single human action when the normal stopping function is inadequate for this purpose

hazards for the purpose of this standard are those which may arise from:

— functional irregularities (malfunctioning of the machinery, unacceptable properties of the processed material, human errors );

— normal operation

NOTE Functions such as reversal or limitation of motion, deflection, shielding, braking, disconnecting, etc may be part of the emergency stop function This standard does not deal with these functions.

3.2 emergency stop equipment

arrangement of components intended to achieve the emergency stop function (see Figure 2, showing the parts of a machine those components can belong)

3.3 control device

that component of the emergency stop equipment which generates the emergency stop signal when the associated manual control (actuator) is operated

3.4 manual control (actuator)

that component of the control device which, when operated, activates the control device, and is

designed to be operated by a person (see 4.4.1)

3.5 machine actuator

a power mechanism used to effect motion of a machine

EN 418:1992

Figure 2 — Emergency stop equipment in machinery

4 Safety requirements

4.1 General requirements

4.1.1 The emergency stop function shall be available

and operational at all times, regardless of the

operating mode

NOTE When emergency stop control devices can be

disconnected (e.g portable teaching pendants) or when

machinery can be partially isolated, care shall be taken to avoid

confusion between active and inactive control devices.

4.1.2 The control device and its actuator shall apply

the principle of positive mechanical action

(see 3.5 of EN 292-2).

NOTE A control switch with positive opening operation, is an

example of a suitable control device According to EN 60947-5-1

(3rd part, subclause 2.2), positive opening operation (of a contact

element) is “the achievement of contact separation as the direct

result of a specified movement of the switch actuator through

non-resilient members (e.g not dependent upon springs)”.

4.1.3 The emergency stop equipment shall neither

be used as an alternative to proper safeguarding

measures nor as an alternative for automatic safety

devices, but it may be used as a back-up measure

4.1.4 After activation of the actuator, the emergency

stop equipment shall operate in such a way that the

hazard is averted or reduced automatically in the

best possible manner

NOTE 1 The statement “in the best possible manner” includes

among others:

— choice of optimal deceleration rate;

— selection of the stop category (see 4.1.5 hereunder),

according to the risk assessment.

NOTE 2 “Automatically” means that, after activation of the

emergency stop actuator, the achievement of the emergency stop

function may be the result of a predetermined sequence of

internal functions.

4.1.5 The emergency stop shall function as:

— either stop category 0, i.e stopping by:

— immediate removal of power to the machine

actuator(s);

— or mechanical disconnection (declutching)

between the hazardous elements and their

machine actuator(s);

and, if necessary, braking (uncontrolled stop);

— or stop category 1, i.e a controlled stop with

power to the machine actuator(s) available to

achieve the stop and then removal of power when

the stop is achieved

4.1.6 The emergency stop equipment shall be

designed such that deciding to actuate the

emergency stop actuator shall not require the

operator to consider the resultant effects (stopping

zone, deceleration rate, etc.)

4.1.7 The emergency stop command shall override all other commands

4.1.8 The response of the machine to the emergency stop command shall not generate any additional hazard

4.1.9 The emergency stop function shall not impair the effectiveness of safety devices or of devices with safety-related functions

NOTE For this purpose, it may be necessary to ensure the continuing operation of auxiliary equipment such as magnetic chucks or braking devices.

4.1.10 The emergency stop function shall not impair any facilities designed to release trapped persons

NOTE The emergency stop function may include initiation of certain of these facilities.

4.1.11 Any action on the actuator which results in generating the emergency stop command shall also result in the latching-in of the control device so that, when the action on the actuator is discontinued, the emergency stop command be maintained until the control device is reset (unlatched) It shall not be possible for the control device to latch-in without generating the stop command

NOTE In case of a failure in the control device (latching-in means included), the function generating the stop command shall have priority over the latching-in function.

4.1.12 Resetting the control device shall only be possible as the result of a manual action on the control device itself

Resetting the control device shall not by itself cause

a restart command

It shall not be possible to restart the machine until all control devices which have been actuated are reset manually, individually and intentionally

4.1.13 The state the machine is brought into by an emergency stop command shall not alter

unintendedly (unexpectedly) during the time the control device is in the actuated condition

4.2 Specific requirements for electrical equipment

See EN 60204-1:1985, paragraphs 5.6.1 and 6.2.7 (prEN 60204-1:1991, paragraphs 9.2.2, 9.2.5.4 and 10.7; see note in clause 2).

EN 418:1992

4.3 Operating conditions, environmental

influences

The components of the emergency stop equipment

shall be selected, assembled and interconnected so

that this equipment meets the expected operating

conditions and environmental influences This

includes:

— consideration of the frequency of operation and

the need for periodic testing (especially reliable

switching should be foreseen in the case of

infrequent operation),

— consideration of vibration, shock, temperature,

dust, foreign bodies, moisture, corrosive

materials, fluids, etc

4.4 Shape, colour and arrangement of

emergency stop actuators

4.4.1 The emergency stop actuators shall be

designed for easy actuation by the operator and

others who may need to operate them Types of

actuators that may be used include:

— mushroom-type push buttons;

— wires, ropes, bars;

— handles;

— in specific applications, foot-pedals without

protective cover

4.4.2 The emergency stop actuators shall be

positioned for easy access and for non-hazardous

operation by the operator and others who may need

to operate them

NOTE Measures against inadvertent operation should not

impair accessibility.

4.4.3 The emergency stop actuators shall be

coloured red As far as a background exists behind

the actuator and as far as it is practicable, it shall be

coloured yellow

NOTE 1 In certain circumstances, it may be useful to provide

labels in addition.

NOTE 2 For electrical equipment, see also subclause 5.6.1.3 of

EN 60204-1:1985 (subclause 10.2.1 of prEN 60204-1:1991;

see note in clause 2).

NOTE 3 When using wires or ropes, it can be useful to improve

their visibility by using marker flags attached to them.

4.4.4 When machinery is divided into several

“emergency stop zones”, the whole system shall be designed so that it is easy to see which emergency stop actuators correspond to which zones

4.5 Additional requirements for wires and ropes, when used as actuators

4.5.1 Consideration shall be given to:

— the amount of deflection necessary for generating the emergency stop signal;

— the maximum deflection possible;

— the minimum clearance between the wire or the rope and the nearest object in the vicinity;

— the force to be applied to the wire or rope in order to actuate the control unit;

— making wires or ropes visible for the operators (e.g by use of marker flags)

4.5.2 In the event of breaking or disengagement of a wire or a rope, the emergency stop signal shall be generated automatically

4.5.3 Resetting facilities should be placed so that the whole length of the wire or rope is visible from those resetting facilities

NOTE If this is not practicable, the instructions for use should state that, after actuation and before resetting, the machinery should be inspected along the whole length of the wire or rope in order to detect the reason for activation.