Bsi bs en 50019 2000 (2006)

covers fm BRITISH STANDARD BS EN 50019 2000 Incorporating Corrigenda Nos 1 and 2 Electrical apparatus for potentially explosive atmospheres — Increased safety “e” The European Standard EN 50019 2000 h[.]

Incorporating Corrigenda Nos 1 and 2

Electrical apparatus for

potentially explosive

atmospheres —

Increased safety “e”

The European Standard EN 50019:2000 has the status of a

British Standard

ICS 29.260.20

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This British Standard, having

been prepared under the

direction of the Electrotechnical

Sector Committee, was published

under the authority of the

Standards Committee and comes

into effect on 15 September 2000

© BSI 13 March 2006

ISBN 0 580 36515 8

National foreword

This British Standard is the official English language version of

EN 50019:2000, including Corrigendum April 2003 It supersedes

BS EN 50019:1994, BS 5501-6:1977 and BS 5000-15:1980, which are withdrawn

The UK participation in its preparation was entrusted by Technical Committee GEL/31, Electrical apparatus for use in explosive atmospheres, to

Subcommittee GEL/31/14, Increased safety “e”, which has the responsibility to:

A list of organizations represented on this subcommittee can be obtained on request to its secretary

Cross-references

The British Standards which implement international or European

publications referred to in this document may be found in the BSI Catalogue

under the section entitled “International Standards Correspondence Index”, or

by using the “Search” facility of the BSI Electronic Catalogue or of British

— aid enquirers to understand the text;

— present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed;

— monitor related international and European developments and promulgate them in the UK

Amendments issued since publication

14497 Corrigendum No 1 28 July 2003 Corrections to EN foreword, Figure 2,

Example 5, Figure 2, Example 7, 5.1.3, Table 5, 6.4.2, 6.6.1.2, 6.8.2, 7.2 and D.2.2

15986 Corrigendum No 2

March 2006 Amendment to supersession details

NORME EUROPÉENNE

Supersedes EN 50019:1994

To be read in conjunction with EN 50014:1997

English version

Electrical apparatus for potentially explosive atmospheres

Increased safety ‘‘e’’

Matériel électrique pour atmosphères

explosibles

Sécurité augmentée ‘‘e’’

Elektrische Betriebsmittel für explosionsgefährdete Bereiche Erhöhte Sicherheit ‘‘e’’

This European Standard was approved by CENELEC on 2000-01-01 CENELEC 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 CENELEC 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 CENELEC member into its own language and

notified to the Central Secretariat has the same status as the official versions

CENELEC members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark,

Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal,

Spain, Sweden, Switzerland and United Kingdom

CENELEC

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

Central Secretariat: rue de Stassart, 35 B-1050 Brussels

© 2000 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members

Ref No EN 50019:2000 E

Contents

1 Scope 5

2 Normative references 5

3 Definitions 7

4 Constructional requirements for all electrical apparatus 11

5 Supplementary constructional requirements for specific electrical apparatus 21

6 Type verifications and type tests 34

7 Routine verifications and routine tests 41

8 Marking 41

Annexes A (informative) Cage motors - Thermal protection in service 43

B (normative) Lampholders and lamp caps for luminaires designed for mains supply 44

C (informative) Combinations of terminals and conductors for general purpose connection and junction boxes 46

D (informative) Additional electrical protection for resistance heating devices 47

E (normative) Cage motors - Methods of test and of calculation 48

F (normative) Type tests for specific forms of resistance heating device and/or resistance heating unit 50

Tables 1 - Creepage distances and clearances 12

2 - Tracking resistance of insulating materials 13

3 - Limiting temperatures for insulated windings 19

4 - Minimum distance between lamp and protective cover 24

5 - Resistance to the effect of short-circuit currents 25

6 - Primary cells 26

7 - Secondary cells 27

8 - Insertion torque and minimum removal torque 35

B.1 - Creepage distances and clearances for screw lamp caps 44

E.1 - Time delay after switching off power for the determination of temperature rise in rated service 48

Figures

1 - Typical parts of a secondary cell 10

2 - Determination of creepage distances and clearances 14-17 3 - Diagram illustrating the determination of time tE 19

4 - Minimum values of the time tE of the motors in relation to the starting current ratio IA/IN 23

5 - Vibration test for luminaires with bi-pin lamp caps/lampholders 36

F.1 - Low temperature bend test apparatus 52

This European Standard supersedes EN 50019:1994 and its corrigendum April 1994

The following dates were fixed:

– latest date by which the EN has to be implemented

at national level by publication of an identical

– latest date by which the national standards conflicting

Annexes designated "normative" are part of the body of the standard Annexes designated "informative" are given for information only In this standard, Annexes B, E and F are normative and Annexes A, C and D are informative

The European Standard was prepared under a mandate given to CENELEC by the European Commission and the European Free Trade Association and covers essential requirements of the EC Directive 94/9/EC This European Standard is to be read in conjunction with EN 50014:1997 - Electrical apparatus for potentially explosive atmospheres - General requirements, and with the European Standards for the specific types of protection listed in the scope of EN 50014:1997 This European Standard should not be considered with any other editions of these standards and their amendments

1 Scope

This European Standard specifies the specific requirements for the construction, testing and marking of electrical apparatus with type of protection "increased safety "e"” intended for use in explosive gas atmospheres

These specific requirements are additional to the general requirements in EN 50014 which are applicable to type of protection "e" This European Standard applies to electrical apparatus with a rated value of supply voltage not exceeding 11 kV (d.c or a.c r.m.s.) that does not produce in normal operation sparks, arcs, or dangerous temperatures

Potentially explosive atmospheres include the presence of combustible dusts for Group I equipment

Except where otherwise stated in the supplementary standards, this standard and the related standards provide protection in accordance with Category 2 or Category M2

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 (including amendments)

EN 50020 Electrical apparatus for potentially explosive atmospheres - Intrinsic safety "i"

EN 50028 Electrical apparatus for potentially explosive atmospheres - Encapsulation ‘m’

EN 50033 Electrical apparatus for potentially explosive atmospheres - Caplights for

mines susceptible to firedamp

EN 50039 Electrical apparatus for potentially explosive atmospheres - Intrinsically safe

electrical systems "i"

EN 60034-1 Rotating electrical machines - Part 1: Rating and performance

(IEC 60034-1:1996, modified)

EN 60034-5 Rotating electrical machines - Part 5: Classification of degrees of protection

provided by enclosures for rotating machines (IEC 60034-5:1981, modified)

EN 60061-1:1993 Lamp caps and holders together with gauges for the control of

interchangeability and safety - Part 1: Lamp caps (IEC 60061-1:1969 + supplements A:1970 to N:1992, modified)

EN 60061-2:1993 Lamp caps and holders together with gauges for the control of

interchangeability and safety - Part 2: Lampholders (IEC 60061-2:1969 + supplements A:1970 to K:1992, modified)

EN 60064 Tungsten filament lamps for domestic and similar general lighting purposes -

Performance requirements (IEC 60064:1993, modified)

EN 60068-2-6 Environmental testing - Part 2: Tests - Test Fc: Vibration (sinusoidal)

(IEC 60068-2-6:1995 + corrigendum March 1995)

EN 60068-2-27:1993 Basic environmental testing procedures - Part 2: Tests - Test Ea and guidance:

Shock (IEC 60068-2-27:1987)

EN 60086-1 Primary batteries - Part 1: General (IEC 60086-1:1996)

EN 60095 series Lead-acid starter batteries (IEC 60095 series, modified)

EN 60238 Edison screw lampholders (IEC 60238:1998)

EN 60285 Alkaline secondary cells and batteries - Sealed nickel-cadmium cylindrical

rechargeable single cells (IEC 60285:1993 + corrigendum August 1993)

(IEC 60317-8:1990 + A1:1997 + A2:1997)

EN 60400 Lampholders for tubular fluorescent lamps and starter holders

(IEC 60400:1999, modified)

EN 60432-1 Safety specifications for incandescent lamps - Part 1 Tungsten filament lamps

for domestic and similar general lighting purposes (IEC 60432-1:1999, modified)

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

EN 60623 Vented nickel-cadmium prismatic rechargeable single cells

(IEC 60623:1990 + A1:1992 and A2:1992)

EN 60662 High-pressure sodium vapour lamps (IEC 60662:1980 + A2:1987 and A3:1990)

EN 60947-1 Low voltage switchgear and controlgear Part 1: General rules

(IEC 60947-1:1999, modified)

EN 61056-1 Portable lead-acid cell and batteries (Valve-regulated types) - Part 1: General

requirements, functional characteristics - Methods of test (IEC 61056-1:1991)

EN 61150 Alkaline secondary cells and batteries - Sealed nickel-cadmium rechargeable

monobloc batteries in button cell design (IEC 61150:1992 + corrigendum March 1992)

EN 61195 Double-capped fluorescent lamps - Safety specifications (IEC 61195:1999)

EN 954-1 Safety of machinery - Safety related parts of control systems - Part 1: General

principles for design

HD 214 S2 Recommended method for determining the comparative tracking index of solid

insulating materials under moist conditions (IEC 60112:1979)

HD 384.3 S2:1995 Electrical installations of buildings - Part 3: Assessment of general

characteristics (IEC 60364-3:1993, modified)

HD 553 S2 Current transformers (IEC 60185:1987 + A1:1990, modified)

HD 566 S1 Thermal evaluation and classification of electrical insulation (IEC 60085:1984) IEC 60050-426:1990 International Electrotechnical Vocabulary - Chapter 426: Electrical apparatus

for explosive atmospheres IEC 60050-486:1991 International Electrotechnical Vocabulary - Chapter 486: Secondary cells and

batteries IEC 60068-2-42 Environmental testing - Part 2: Tests - Test Kc : Sulphur dioxide test for

contacts and connections IEC 60079-4 Electrical apparatus for explosive gas atmospheres - Part 4: Method of test for

ignition temperature IEC 60664-1:1992 Insulation coordination for equipment within low-voltage systems - Part 1:

Principles, requirements and tests (harmonized as HD 625.1, modified) IEC 60755 General requirements for residual current operated protective devices

3 Definitions

For the purposes of this European Standard, the definitions of EN 50014 and also the following apply

NOTE Where a word, for example "battery", is shown in parentheses in a term, it may be omitted when no risk of confusion or misunderstanding is likely to arise

3.1

increased safety "e"

a type of protection in which additional measures are applied so as to give increased security against the possibility of excessive temperatures and of the occurrence of arcs and sparks inside and on external parts

of electrical apparatus which does not produce arcs or sparks in normal service [IEC 60050-426-08-01]

NOTE 1 This type of protection is denoted by "e" and the "additional measures" are those required for compliance with this European Standard

NOTE 2 Apparatus producing arcs or sparks in normal service is excluded by this definition

3.2

limiting temperature

the maximum permissible temperature of apparatus or parts of apparatus equal to the lower of the two temperatures determined by:

a) the danger of ignition of the explosive gas atmosphere;

b) the thermal stability of the materials used [IEC 60050-426-08-02]

3.3

initial starting current IA

highest r.m.s value of current absorbed by an a.c motor when at rest or by an a.c magnet with its armature clamped in the position of maximum air gap when supplied at rated voltage and rated frequency

NOTE Transient phenomena are ignored

3.4

starting current ratio IA/IN

ratio between initial starting current IA and rated current IN

rated short-time thermal current Ith

R.M.S value of the current required to heat up the conductor within 1 s from the temperature reached in rated service at the maximum ambient temperature to a temperature that does not exceed the limiting temperature

3.7

rated dynamic current Idyn

peak value of the current, the dynamic effect of which the electrical apparatus can sustain without damage

NOTE 1 Transients are disregarded

NOTE 2 Both open circuit conditions and normal operating conditions are taken into account

3.12 Component part of cells and batteries

3.12.1

container (of a cell)

a container for the plate pack and electrolyte of a cell made of a material impervious to attack by the electrolyte [IEC 60050-486-02-20]

3.12.2

(battery) container

enclosure to contain the battery

NOTE The cover is a part of the battery container

a conductor of electricity used for carrying current between cells [IEC 60050-486-02-31]

3.13 Resistance heating device and resistance heating unit

3.13.1

resistance heating device

part of a resistance heating unit, comprising one or more heating resistors, typically composed of metallic conductors or an electrically conductive compound suitably insulated and protected

3.13.2

resistance heating unit

apparatus comprising an assembly of one or more resistance heating devices, associated with any devices necessary to ensure that the limiting temperature is not exceeded

NOTE This standard does not require that protective devices outside the hazardous area have type of protection "e"

is reduced to an insignificant amount

NOTE The temperature of the surface of the resistance heating device is then effectively the temperature of the environment

3.13.5

stabilized design

concept where the temperature of the resistance heating device or unit will, by design and use, stabilize below the limiting temperature, under the most unfavourable conditions, without the need for a protective system to limit the temperature

1 2 3

4 5

6 7

8 9

10 11

12 13

6 - Electrolyte-tight lid seal

7 - Filler and vent plug

4 Constructional requirements for all electrical apparatus

The requirements of this clause apply, unless otherwise stated in clause 5, to all electrical apparatus with type of protection "e" They are additional to the general requirements of EN 50014 (see clause 1) and are themselves supplemented for certain electrical apparatus by the supplementary requirements in clause 5

4.1 Terminals for external connections

Terminals for connections to external circuits shall be generously dimensioned to permit the effective connection of conductors of cross section at least equal to that corresponding to the rated current of the electrical apparatus

The number and sizes of conductors that can be safely connected to terminals should be specified in the descriptive documents according to 23.2 of EN 50014

NOTE 1 Service conditions may require the provision of larger terminals and the conductor size corresponding to the rated current may depend upon the application

These terminals shall:

 be fixed in their mountings without possibility of self-loosening; and

 be constructed in such a way that the conductors cannot slip out from their intended location; and

 be such that proper contact is assured without such damage to the conductors as would impair their ability to fulfil their function, even when multi-stranded conductors are used in terminals intended for direct clamping of a conductor

NOTE 2 The use of "crimped" cable terminations is not forbidden provided that the above requirements are fulfilled

In particular, terminals shall not:

 have sharp edges which could damage the conductors;

 be able to turn, twist or be permanently deformed during normal tightening, for which the conditions shall

be defined by the manufacturer of the apparatus

Terminals shall be such that the contact they assure is not appreciably impaired by temperature changes occurring in normal service The contact pressure shall not be transmitted through insulating material

Terminals intended for clamping stranded conductors shall include a resilient intermediate part Terminals for connecting conductors of cross sections not exceeding 4 mm2 shall also be suitable for the effective connection of conductors having a smaller cross section

NOTE 3 Special precautions against vibration and mechanical shock may be required

NOTE 4 Special precautions against electrolytic corrosion should be considered

4.2 Internal connections (integral part of the apparatus)

Connections within electrical apparatus and forming an integral part of that apparatus shall not be subject to undue mechanical stress Only the following means for the connection of conductors are permitted:

a) screwed fasteners with locking;

b) crimping;

c) soldering, provided that the conductors are not supported by the soldered connections alone;

d) brazing;

e) welding;

f) any means of connection complying with 4.1.

NOTE Special precautions against electrolytic corrosion should be considered

4.3 Clearances

Clearances between bare conductive parts at different potentials shall be as given in Table 1 with a minimum value for external connections of 3 mm

NOTE 1 For the requirements for lamps with screw caps see B.1.4

Clearances shall be determined as a function of the working voltage (definition 3.11) specified by the manufacturer of the apparatus Where the apparatus is intended for more than one rated voltage or for a range of rated voltage, the value of working voltage to be used shall be based on the highest value of rated voltage In determining the clearances, examples 1 to 11 inclusive in Figure 2 illustrate the features to be taken into account and the appropriate clearances

NOTE 2 These examples are identical with those given in IEC 60664-1

Table 1 — Creepage distances and clearances

Minimum creepage distance Material group, mm

4.4.1 The required values of creepage distance are dependent on the working voltage, the resistance to

tracking of the electrical insulating material and its surface profile

Table 2 gives the grouping of electrical insulating materials according to the Comparative Tracking Index (CTI) determined in accordance with HD 214 S2 Inorganic insulating materials, for example glass and ceramics, do not track and need not therefore be subjected to the determination of the CTI They are conventionally classified in Material Group I

The grouping given in Table 2 is applied to insulating parts without ribs or grooves If there are ribs or grooves in accordance with 4.4.3, the minimum permissible creepage distances for working voltages up to

1 100 V shall be based on the next higher group, for example Group I instead of Group II

NOTE 1 The material groups are identical with those given in IEC 60664-1

NOTE 2 Transient overvoltages are ignored as they will not normally influence tracking phenomena However, temporary and functional overvoltages may have to be considered, depending upon the duration and frequency of occurrence (see IEC 60664-1 for additional information)

Table 2 — Tracking resistance of insulating materials Material group Comparative tracking index

4.4.2 Creepage distances between bare conductive parts at different potentials shall be as given in Table 1,

with a minimum value for external connections of 3 mm and shall be determined as a function of the working voltage specified by the manufacturer of the apparatus

NOTE For the requirements for lamps with screw caps see B.1.4

4.4.3 In determining the creepage distance, examples 1 to 11 (see Figure 2) inclusive illustrate the features

to be taken into account and the appropriate creepage distance The value of dimension X is 2,5 mm

The effect of ribs and grooves may be taken into account provided that:

a) ribs on the surface are at least 2,5 mm high and of a thickness appropriate to the mechanical strength ofthe material with a minimum value of 1,0 mm and;

b) grooves in the surface are at least 2,5 mm deep and at least 2,5 mm wide If the associated clearancedistance is less than 3 mm, the minimum groove width may be reduced to 1,5 mm

NOTE 1 Projections above or depressions below the surface are considered as being either ribs or grooves irrespective of their geometric form

NOTE 2 Cemented constructions (see clause 12 of EN 50014) are considered to be solid parts

Example 1

< X

Condition: Path under consideration includes a parallel-or

converging-sided groove of any depth with a width less than

Condition: Path under consideration includes a parallel-sided

groove of any depth d equal to or more than X mm

Rule: Clearance is the "line of sight" distance Creepage path follows the contour of the groove

Example 3

= X

Condition: Path under consideration includes a V-shaped

groove with a width greater than X mm Rule: Clearance is the "line of sight" distance Creepage path follows the contour of the groove but "short-circuits" the bottom

of the groove by X mm link

Example 4

Condition: Path under consideration includes a rib Rule: Clearance is the shortest direct air path over the top of

the rib Creepage path follows the contour of the rib

Example 5

Condition: Path under consideration includes an uncemented

joint with grooves less than X mm

Rule: Creepage and clearance path is the "line of sight" path is the "line of sight" distance shown

Example 6

≥ X

≥ X

Condition: Path under consideration includes an uncemented

joint with grooves equal to or more than X mm wide on each

Condition: Path under consideration includes an uncemented

joint with a groove on one side less than X mm wide and the

groove on the other side equal to or more than X mm wide

Rule: Clearance and creepage paths are as shown

Example 8

Condition: Creepage distance through uncemented joint is less

than creepage distance over barrier

Rule: Clearance is the shortest direct air path over the top of the barrier

Example 9

≥ X

≥ X

Gap between head of screw and wall of recess wide enough to

be taken into account

Measurement of creepage distance is from screw to wall when

the distance is equal to X mm

Example 11

D d

Figure 2 — Determination of creepage distances and clearances (concluded)

4.5 Solid electrical insulating materials

NOTE This term describes the form in which the materials are used and not necessarily that in which they are supplied, for example insulating varnishes when cured are considered as being solid electrical insulating materials

4.5.1 The mechanical characteristics of the insulating materials that affect their functional behaviour, for

example strength and rigidity, shall be satisfactory either:

a) at a temperature up to at least 20 K above the maximum temperature attained in rated service and atleast 80 qC; or

b) for insulated windings (see 4.7.3 and Table 3), for internal wiring (see 4.8) and for cables permanentlyconnected to electrical apparatus (see 14.1 of EN 50014) up to the maximum temperature attained inrated service

4.5.2 Insulating parts made of plastics or laminates where the original surface is removed during

manufacture or is damaged shall be coated with an insulating varnish having at least the same grading according to CTI as the original surface This requirement does not apply to materials when these actions have not affected the grading according to CTI or when the specified creepage distance is provided by other parts not subjected to these actions

4.6 Windings

4.6.1 Insulated conductors shall comply with the requirements in 4.6.1.1 or 4.6.1.2

4.6.1.1 The conductors shall be covered with at least two layers of insulation

4.6.1.2 Enamelled round winding wires shall be in accordance with either:

a) Grade 1 of EN 60317-3, EN 60317-7 or EN 60317-8 provided that:

 when tested in accordance with clause 13 of EN 60317-3, EN 60317-7 or EN 60317-8 there shall be

no failure with the minimum values of breakdown voltage listed for Grade 2 and that;

 when tested in accordance with clause 14 of EN 60317-3, EN 60317-7 or EN 60317-8 there shall be not more than six faults per 30 m of wire irrespective of diameter; or

b) Grade 2 of EN 60317-3, EN 60317-7 or EN 60317-8

4.6.2 Windings after having been fastened or wrapped shall be dried to remove moisture before

impregnation with a suitable impregnating substance by dipping, trickling or vacuum impregnation Coating

by painting or spraying is not recognized as impregnation

The impregnation shall be carried out in compliance with the specific instructions of the manufacturer of the relevant type of impregnating substance and in such a way that the spaces between the conductors are filled

as completely as possible and that good cohesion between the conductors is achieved

This does not apply to fully insulated coils and conductors of high voltage (over 1 100 V) windings if, prior to their fitting into the electrical apparatus, the slot portions and end windings of these coils and conductors have been impregnated, provided with filling material or otherwise insulated in an equivalent way, and if, after assembly, they are no longer accessible for the stated insulating procedures

If impregnating substances containing solvents are used, the impregnation and drying processes shall be carried out at least twice

4.6.3 The nominal conductor diameter of wires used for windings shall be at least 0,25 mm

NOTE Windings made with wires having a nominal conductor diameter less than 0,25 mm may be used if they are protected by another of the standard types of protection listed in EN 50014

4.6.4 Sensing elements of resistance thermometers are not considered to be windings but when applied to

the windings of rotating electrical machines they shall be positioned within the slots and impregnated or sealed with the windings

4.7 Temperature limitations

4.7.1 No part of an electrical apparatus shall attain a temperature in excess of that determined by the

thermal stability of the materials used Furthermore, no surface of any part of an electrical apparatus including the surface of internal parts to which the potentially explosive atmosphere might have access shall attain a temperature in excess of the maximum surface temperature prescribed in clause 5 of EN 50014, except for lamps in luminaires for which the requirement is in 5.2.4

NOTE There are two conditions to be satisfied, either of which may prove to be the limiting feature for a particular apparatus or part of

an apparatus

4.7.2 The permissible temperature of conductors and other metal parts is furthermore limited by:

a) reduction of their mechanical strength;

b) unacceptable mechanical stress due to thermal expansion;

c) damage to neighbouring insulating parts

In determining the temperature of conductors, both the self-heating of the conductors and the effect of heating by neighbouring parts shall be taken into account

Table 3 — Limiting temperatures for insulated windings

Thermal class of insulating material according to HD 566 Temperature

T = thermometer method (only permissible if the resistance method is not possible)

NOTE 1 Includes, as a temporary measure until values have been prescribed, the higher thermal classes of insulating material numerically denoted in HD 566

NOTE 2 Theses values are composed of the ambient temperature, the temperature rise of the winding in rated service and the

increase of temperature during time tE (see Figure 3)

Key:

A - Highest permissible ambient temperature T - Temperature

B - Temperature in rated service 1 - Temperature rise in rated service

C - Limiting temperature (4.7) 2 - Temperature rise during stalled rotor test

t - Time

Figure 3 — Diagram illustrating the determination of time tE

4.7.3 Limiting temperature of insulated windings shall not exceed the values given in Table 3 which take

account of the thermal endurance of insulating materials, provided that the electrical apparatus still complies with 4.7.1

4.7.4 Windings shall be protected by suitable devices to ensure that the limiting temperature (see 4.7.1,

4.7.2 and 4.7.3) cannot be exceeded in service Such devices are not required if the temperature of the windings does not exceed the limiting temperature given for rated service in 4.7.3, even when the windings are subjected to continuous overload (for example, the locked rotor of a motor) or if the windings cannot be subjected to overload

NOTE The protective device may be inside and/or outside the electrical apparatus

4.8 Internal wiring

Wiring which might come into contact with a conductive part shall be either mechanically protected or fixed to avoid any damage

4.9 Degrees of protection provided by enclosures

4.9.1 The degrees of protection as defined in EN 60529 and EN 60034-5 shall be as prescribed in a) or b)

unless otherwise specified in 4.9.2, 4.9.3 or clause 5

a) Enclosures containing bare conductive parts shall provide at least degree of protection IP 54

b) Enclosures containing only conductive parts with insulation according to 4.5 shall provide at least degree

of protection IP 44

4.9.2 The enclosure of an electrical apparatus may be provided with drain holes or ventilation openings to

prevent the accumulation of condensation

a) For Group I, compliance with 4.9.1 is required

b) For Group II, the inclusion of the drain holes or ventilation openings may reduce the degree of protectionprovided by enclosure according to 4.9.1 but not below IP 44 in 4.9.1a) or IP 24 in 4.9.1b)

When the presence of drain holes or ventilation openings reduces the degree of protection below the requirements of 4.9.1, the details of the drain holes or ventilation openings, including position and dimensions, shall be stated by the manufacturer and included in the descriptive documents according to 23.2

of EN 50014 The marking of apparatus with drain holes and ventilation openings that reduce the degree of protection shall include the sign "X" in accordance with i) of 27.2 of EN 50014 and the degree(s) of protection provided by enclosure

4.9.3 When there are circuits or systems with type of protection "i" according to EN 50020 or EN 50039, or

parts of these, within the enclosure, either:

a) the covers of the enclosure permitting access to energized non-intrinsically-safe circuits shall have alabel with the wording “DO NOT OPEN WHEN NON-INTRINSICALLY-SAFE CIRCUITS AREENERGIZED”; or

b) all live parts not protected by type of protection "i" shall have a separate internal cover providing at leastdegree of protection IP 30 when the enclosure of the apparatus is open

The internal cover shall have a label with the wording “DO NOT OPEN WHEN ENERGIZED” or other wording that would otherwise be required by EN 50014 to be on the cover of the enclosure of the apparatus The cover of the enclosure of the apparatus shall have a label with the wording “NON-INTRINSICALLY-SAFE CIRCUITS PROTECTED BY INTERNAL IP 30 COVER”

NOTE The purpose of the internal cover, when fitted, is to provide a minimum acceptable degree of protection against the access to energized non-intrinsically-safe circuits when the enclosure is opened for short periods to permit checking or adjustment of energized intrinsically-safe circuits

4.10 Fasteners

For Group I electrical apparatus containing bare live parts, special fasteners complying with the requirements

of 9.2 of EN 50014 shall be used

5 Supplementary constructional requirements for specific electrical apparatus

These requirements supplement those of clause 4 of this standard which are applicable also, unless otherwise stated, to the specific electrical apparatus considered in 5.1 to 5.8 inclusive and also to the other electrical apparatus considered in 5.9

5.1 Rotating electrical machines

5.1.1 Degrees of protection provided by enclosure

As an exception to the requirements in 4.9 for protection against the ingress of solid foreign objects and water, the following degrees of protection provided by enclosure suffice for the enclosures of rotating electrical machines (except for terminal boxes and bare conductive parts) installed in clean environments and regularly supervised by trained personnel:

a) for Group I, IP 23;

b) for Group II, IP 20

Solid foreign objects shall be prevented from falling vertically through the ventilating openings into the enclosures of machines

The marking of rotating electrical machines designed for use only in clean environments shall include the sign "X", in accordance with 27.2 i) of EN 50014, and the degree of protection provided by enclosure

5.1.2 Internal fans

Internal fans shall comply with the requirements for clearances and materials specified for external fans in 17.3 and 17.4 of EN 50014

5.1.3 Minimum radial air gap

The minimum radial air gap between the stator and the rotor (in mm), when the rotating electrical machine is

at rest, shall not be less than the value given by the following formula:

75,025,0780

5015

,0

where:

D is the rotor diameter in millimetres, which in the formula for the minimum radial air gap is subject to a minimum value of 75 and a maximum value of 750; and

n is the maximum rated speed in rev/min and is subject to a minimum value of 1 000; and

r has the value given by the following formula and is subject to a minimum value of 1,0,

mm)(indistance,rotor

1,75

mm)(inlengthcore

D

r

b has the value of 1,0 for machines with rolling bearings or 1,5 for machines with plain bearings

NOTE The minimum radial air gap is not directly proportional to the supply frequency or number of poles as can be seen from the example of a 2/4 pole motor with rolling bearings designed for a 50/60 Hz supply and having a rotor with a diameter of 60 mm and

a core length of 80 mm

D is then taken as 75, the minimum value; n as 3 600, the maximum value;

b as 1,0; r = 80/(1,75 x 60), that is 0,76 approximately and therefore taken as 1,0; when the minimum

radial air gap becomes approximately 0,25 mm

00000

1

6003750250780

507515

5.1.4 Machines with cage rotors

In addition to the requirements of 5.1.1, 5.1.2 and 5.1.3, the requirements of this sub-clause apply to machines with cage rotors, including synchronous machines with "cage rotor" starting or damping windings

5.1.4.1 The bars of cage rotors shall be brazed or welded to the short-circuiting rings, unless the bars and rings of the cages are manufactured as a single unit

The bars shall fit tightly in the slots in order to prevent sparking between bars and rotor cores during starting

NOTE 1 This may be achieved, for example, by casting aluminium under pressure, by supplementary lining in slots containing single bars, by wedging the bars or by keying

NOTE 2 The bars and rings of cage rotors are not considered to be bare conductive parts in applying 4.3, 4.4, 4.9 and 5.1.1

5.1.4.2 The limiting temperature of the rotor shall not be exceeded even during starting The limiting temperature is the lesser of 300 qC or the value specified in 4.7

5.1.4.3 When intended for use with a current-dependent device to protect against the occurrence of

non-permissible temperatures, the starting current ratio IA/IN and the time tE shall be determined and marked

The length of time tE shall be such that, when the rotor is locked, the motor can be disconnected by a

current-dependent protective device before time tE has elapsed In general, this is possible if the minimum

values for tE given in Figure 4 as a function of the starting current IA/IN are exceeded Values of time tE below the values in Figure 4 are permissible only if a suitable overload protective device is used for the machine and it is shown to be effective by test This device shall be identified by marking on the apparatus

In no case shall:

 the value of time tE be less than 5 s; and

 the value of the starting current ratio IA/IN be more than 10

2

5102040

IA /I

N

Figure 4 — Minimum values of the time tE of motors in relation to the starting current ratio IA/IN

5.1.4.4 When intended for use with winding temperature sensors associated with protective devices to

protect against the occurrence of non-permissible temperatures, the starting current ratio IA/IN shall be

determined and marked Time tE is not required to be determined and marked

Winding temperature sensors associated with protective devices shall be considered adequate for the thermal protection of the machine if the requirements of 4.7.4 are satisfied even when it is stalled The associated protective devices shall be identified by marking on the machine

In no case shall the value of the starting current ratio IA/IN be more than 10

5.1.4.5 Motors supplied at varying frequency and voltage by a converter shall be tested and certified for this

duty as a unit in association with the converter specified in the descriptive documents according to 23.2 of

EN 50014 and with the protective device provided

5.1.4.6 Information on the thermal protection in service of cage motors by overload protective devices is

given in Annex A

NOTE Annex A should be taken into account as far as applicable for motors supplied by a converter

5.2 Luminaires designed for mains supply

NOTE This subclause does not give requirements for signal and similar small lamps (see 5.9)

5.2.1 The light source shall be one of the following:

a) fluorescent lamps of the cold starting type with single-pin caps (Fa6) complying with the requirements of

5.2.2 For fluorescent tubes the distance between the lamp and the protective cover shall be not less than

5 mm unless the protective cover is an outer tube, in which case the minimum distance is 2 mm

For other lamps the distance between the lamp and the protective cover shall be not less than the value given in Table 4, according to the lamp wattage

Table 4 — Minimum distance between lamp and protective cover

5.2.3 Lampholders shall comply with the requirements given in Annex B

5.2.4 The surface temperature indicated in clause 5 of EN 50014 may be exceeded when the highest

surface temperature of the lamp inside the luminaire is at least 50 K below the lowest temperature of ignition, inside the luminaire, of the potentially explosive atmosphere for which the luminaire is intended, as determined by tests made under the most unfavourable conditions of use This dispensation is only valid for the gas atmospheres indicated in the certificate, these being those for which the tests have given satisfactory results

NOTE Measurements on existing luminaires have established that the temperatures at which ignition will occur inside the luminaires are considerably higher than the ignition temperatures measured in accordance with IEC 60079-4

5.2.5 The temperature at the rim of the lamp cap and at the soldering point of the lamp cap shall not exceed

the limiting temperature The limiting temperature is the lesser of 195 qC or the value specified in 4.7

5.2.6 The limiting temperature of ballasts for tubular fluorescent lamps shall not be exceeded even in the

case of ageing lamps (rectifying effect) The type test is given in 6.3.2

5.3 Caplamps (except for Group I) and hand lamps with their own source of supply

The lamp shall be protected against mechanical damage by a protective cover The distance between this protective cover and the lamp when the latter is securely inserted shall be at least 1 mm If the lamp is inserted in a spring-loaded lampholder, the spring travel shall be at least 3 mm The protective cover shall be:

a) protected by a guard; or

b) if not exceeding 50 cm2 in area, protected by a protruding rim with a height of at least 2 mm; or

c) if exceeding 50 cm2 in area, able to withstand the mechanical test requirements specified for guards,protective covers, fanhoods, cable entries in 23.4 of EN 50014

Switching devices in the lamp circuit which produce sparks or arcs in normal service, including devices such

as reed switches where the sparks or arcs are produced in hermetic enclosures, shall either be electrically or mechanically interlocked to prevent contact separation within the hazardous area or they shall be protected

by another of the standard types of protection listed in EN 50014

5.4 Measuring instruments and instrument transformers

5.4.1 Measuring instruments and instrument transformers shall be able to withstand continuously 1,2 times

their rated current and/or their rated voltage as appropriate without exceeding the limiting temperatures according to 4.7

5.4.2 Current transformers and the current-carrying parts of measuring instruments (excluding voltage

circuits) shall be able to withstand thermal and dynamic stresses resulting from currents at least equal to the values stated in Table 5 and for the periods as indicated in 6.4 with no reduction in their security against explosions

5.4.3 The temperature attained during the passage of a current equal to the thermal current limit Ith shall not exceed the limiting temperature specified in 4.7 and in no case shall it exceed 200 qC

Table 5 — Resistance to the effect of short-circuit currents Current Current transformers and current-carrying parts of

measuring instruments

NOTE 1 2,5 Iscis the maximum peak value of the short-circuit current

NOTE 2 The factors 1,1 and 1,25 are safety factors It follows that the r.m.s value of the permissible short-circuit current in service

may not exceed Ith/1,1 and its peak value may not exceed Idyn/1,25

5.4.4 Where the current-carrying parts of measuring instruments are supplied by current transformers, the

values of Ith and Idyn need only equal the current flowing in the short-circuited secondary windings of the

current transformer with its primary windings carrying the currents Ith and Idyn applicable to them

5.4.5 Measuring instruments with moving coils are not permitted

5.4.6 If the secondary circuit of the current transformer extends outside the apparatus, this shall be marked

with the sign "X" according to 27.2 i) of EN 50014 and the descriptive documents according to 23.2 of

EN 50014 shall draw attention to the need to guard against the secondary circuit becoming open-circuited in service

5.5 Transformers other than instrument transformers

Transformers, other than instrument transformers for which the requirements are given in 5.4, shall be tested

in accordance with 6.5

5.6 Cells and batteries

5.6.1 Acceptable electrochemical systems

Only those cells listed in Tables 6 and 7 for which IEC or CENELEC cell standards exist shall be used

Table 6 — Primary cells

Maximum open circuit voltage

NOTE 1 Zinc/Manganese dioxide cells are listed in EN 60086-1 but not classified by a type letter

NOTE 2 The cell marked * may only be used once an IEC or CENELEC cell standard exists