1、BRITISH STANDARD BS 6121-5:2005 Mechanical cable glands Part 5: Code of practice for selection, installation and inspection of cable glands and armour glands ICS 21.140; 29.080.20 BS 6121-5:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on
2、 21 February 2005 BSI 21 February 2005 First published January 1993 Second edition February 2005 The following BSI references r e l a t e t o t h e w o r k o n t h i s British Standard: Committee reference GEL/20/11/1 Draft for comment 03/308266 DC ISBN 0 580 45375 8 Committees responsible for this
3、British Standard The preparation of this British Standard was entrusted by Technical Committee GEL/20, Electric cables, to Subcommittee GEL/20/11/1, Cable glands, upon which the following bodies were represented: BEAMA Ltd. Council for Electrical Equipment BEAMA Installation Ltd. British Approvals S
4、ervice for Cables British Cables Association Gland Manufacturers Technical Committee Co-opted members Amendments issued since publication Amd. No. Date CommentsBS 6121-5:2005 BSI 21 February 2005 i Contents Page Committees responsible Inside front cover Foreword ii 1S c o p e 1 2 Normative reference
5、s 1 3T e r m s a n d d e f i n i t i o n s 1 4G e n e r a l 2 5 Selection of glands 3 6I n s t a l l a t i o n 8 7 Electrical continuity test 10 8 Inspection and testing 11 Annex A (informative) Cable glands and armour glands corresponding to the type designations given in BS 6121-1:1989 13 Bibliogr
6、aphy 14 Table A.1 Cable glands and armour glands corresponding to the type designations given in BS 6121-1:1989 13BS 6121-5:2005 ii BSI 21 February 2005 Foreword This part of BS 6121 has been prepared by Subcommittee GEL/20/11/1. It supersedes BS 6121-5:1993 which is withdrawn. This part of BS 6121
7、has been updated to refer to the properties of cable glands and armour glands specified in BS EN 50262 and in the new edition of BS 6121-1, respectively, which specify performance, rather than construction as was the case in earlier editions of BS 6121. Some of the testing recommended in BS 6121-5:1
8、993 has been removed because this testing is now specified in BS EN 50262 and/or BS 6121-1. This revision of BS 6121-5 includes new recommendations for selection of glands on the basis of mechanical and electrical properties, as well as new clauses relating electrical properties to installation prac
9、tice. As a code of practice, this part of BS 6121 takes the form of guidance and recommendations. It should not be quoted as if it were a specification and particular care should be taken to ensure that claims of compliance are not misleading. It has been assumed in the drafting of this standard tha
10、t the execution of its provisions will be entrusted to appropriately qualified and competent people, for whose use it has been prepared. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a Briti
11、sh 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, pages 1 to 14, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document
12、was last issued.BS 6121-5:2005 BSI 21 February 2005 1 1 Scope This part of BS 6121 gives recommendations on the selection, installation and inspection of cable glands conforming to BS EN 50262, armour glands conforming to BS 6121-1, and accessories, for industrial, commercial and domestic use. It is
13、 not applicable to glands for use with fibre-optic cables or mineral insulated cables. It is not applicable to glands for installation in explosive atmospheres. NOTE Requirements for installation of electrical equipment in explosive gas atmospheres are specified in BS EN 60079-14. Requirements for i
14、nstallation of electrical equipment in explosive dust atmospheres are specified in BS EN 50281-1-2. This part of BS 6121 is intended for use by specifiers of electrical installations, by installers and by those responsible for carrying out inspections. 2 Normative references The following referenced
15、 documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. BS 6121-1:2005, Mechanical cable glands Part 1: Armour glands Requirement
16、s and test methods. BS 7671:2001 including amendments 1:2002 and 2:2004, Requirements for electrical installations IEE Wiring Regulations. Sixteenth edition. BS EN 50262:1999 including amendments 1:2001 and 2:2004, Cable glands for electrical installations. 3 Terms and definitions For the purposes o
17、f this part of BS 6121, the terms and definitions given in BS EN 50262:1999 and BS 6121-1:2005 and the following apply. 3.1 non-integral earth connection accessory with a means of attaching an additional earth conductor which is fitted to a cable gland or armour gland and which, when installed, prov
18、ides a protective connection to earth NOTE A protective connection to earth is also known as a PE function. 3.2 integral earth connection connection point with a means of attaching an additional earth conductor which is permanently attached to a cable gland or armour gland and which, when installed,
19、 provides a protective connection to earth 3.3 clearance hole hole in the wall of an enclosure which is not threaded internally 3.4 functional earth earth connection required for the correct operation of a piece of equipment NOTE An example of a functional earth is the earth connection to a co-axial
20、 radio-frequency cable or screened data cable. This connection reduces external interference and is essential to the functioning of the equipment; it does not work properly without it. 3.5 circuit protective conductor conductor used to protect people against electric shock by interrupting the supply
21、 in the event of an earth fault and so causing the fuse or circuit breaker to tripBS 6121-5:2005 2 BSI 21 February 2005 4 General 4.1 Properties of glands 4.1.1 BS EN 50262 and BS 6121-1 each specifies requirements to which all glands have to conform in order to be deemed to conform to the respectiv
22、e standard. Each of these standards also specifies additional requirements to which glands have to conform if the manufacturer wishes to claim that the glands have particular additional properties. 4.1.2 BS EN 50262 also provides a “classification” of cable glands according to the material from whic
23、h they are made, their mechanical and electrical properties, the degree of ingress protection they provide and whether they have a single orifice or a multi-orifice seal. 4.1.3 Glands conforming to BS EN 50262 or to BS 6121-1 are supplied with manufacturers information including the following: the m
24、aterial(s) from which the glands have been manufactured; the type of seal (cable glands only); the entry thread length; the range of cable sizes with which the glands can be used; the impact category (indicating the impact resistance on a scale from 1 to 8, where 8 is the highest resistance). 4.1.4
25、BS EN 50262 and BS 6121-1 specify the following basic requirements for all glands: provision of basic cable retention; resistance to excess torque; provision of a minimum degree of ingress protection of IP54 (for cable glands) or of IP2X (for armour glands); 4.1.5 BS EN 50262 and BS 6121-1 specify t
26、he following additional requirements for glands for which the manufacturer claims the relevant additional properties: provision of cable anchorage (cable glands only): Type A: glands resistant to repetitive cable pulling or twisting at low pull forces; Type B: glands resistant to repetitive cable pu
27、lling or twisting at higher pull forces; provision of cable retention for armoured cable (cable glands only): Class A: glands resistant to low pull forces; Class B: glands resistant to higher pull forces; provision of equipotential bonding to the enclosure (see Note); provision of electrical bonding
28、 to metallic layer(s) in a cable; provision of a protective connection to earth; Category A: glands resistant to low earth fault current; Category B: glands resistant to intermediate earth fault current; Category C: glands resistant to high earth fault current; electrical insulating characteristics
29、cable glands only); provision of a degree of ingress protection above IP54 (cable glands only); a working temperature range extending outside the range p20 C to +65 C (cable glands only); resistance to the corrosive effects of salt and sulfur dioxide laden atmospheres. NOTE If a gland provides equi
30、potential bonding to an enclosure this means that there is electrical continuity between the various metallic parts of the gland and that part of the gland which is used to make a connection to the enclosure.BS 6121-5:2005 BSI 21 February 2005 3 4.2 Type designations for glands Previous editions of
31、BS 6121 specified requirements for design and construction of glands and gave type designations for these glands. Manufacturers literature no longer specifies glands by reference to these old type designations, but some catalogues still refer to them and manufacturers sometimes use them as product c
32、odes. To enable the specifier or installer to select the correct gland, descriptions of glands specified in BS EN 50262 and BS 6121-1:2005 which correspond to type designations given in BS 6121-1:1989 are given in Annex A. In case of doubt, the gland manufacturer should be consulted. 5 Selection of
33、glands 5.1 Basic principles 5.1.1 General The following basic principles should be applied to the selection of cable glands and armour glands. For domestic and commercial installations, a cable gland or armour gland which conforms to the basic requirements (i.e. is not claimed to have any additional
34、 properties) and which has an impact category of at least 3 should be selected. However, for installations where there is no risk of the gland suffering an impact (for example, because it is inside another enclosure) a gland of a lower impact category (1 or 2) may be selected. For light industrial i
35、nstallations, a cable gland or armour gland which conforms to the basic requirements and which has an impact category of at least 5 should be selected. For heavy-duty industrial installations, where there is a risk of damage by personnel or moving objects, a metallic or composite cable gland or armo
36、ur gland which has an impact category of at least 7 and which provides equipotential bonding should be selected. NOTE The test conditions corresponding to the different impact categories are given in BS EN 50262:1999, Table 4. In case of doubt regarding any aspect of gland selection, the gland manuf
37、acturer should be consulted. 5.1.2 Glands for applications in which a seal is not required For armoured cables, where a seal is not required, an armour gland should be selected. 5.1.3 Glands for applications in which a seal is required For applications in which a seal is required between the cable s
38、heath and the gland, a cable gland should be selected in accordance with the following recommendations. If the cable is unarmoured, a cable gland should be selected. If the cable is armoured, a cable gland providing retention for armoured cable should be selected. If a seal is required on two separa
39、te cable sheaths, then a cable gland with inner and outer seals should be selected. If the cable is to hang from the gland then a cable gland providing cable anchorage should be selected. See also 5.8. 5.1.4 Glands for use in extreme conditions If a cable gland or armour gland is required which has
40、resistance to extreme conditions not covered by the requirements specified in BS EN 50262 or BS 6121-1 (e.g. resistance to chemical attack, resistance to ingress of water in deluge conditions, resistance to strong ultraviolet light), advice should be sought from the gland manufacturer.BS 6121-5:2005
41、 4 BSI 21 February 2005 5.2 Selection according to size and profile of the cable It is essential that the gland selected is of the correct size for, and suitable for the profile of, the cable with which it is to be used. The specifier or installer should ensure that the diameter or other dimensions
42、of the cable with which the gland is to be used are within the range for which the gland is suitable, as stated in the gland manufacturers information. In the case of a cable gland, if the gland is claimed to provide anchorage, the range of cable sizes for which the gland provides a seal might be di
43、fferent from the range of cable sizes for which the gland provides anchorage. This means that for cable sizes within the range for which a seal is provided, but outside the range for which anchorage is provided, the gland provides only retention. This needs to be taken into account when selecting th
44、e size of gland to be used. 5.3 Selection according to the gland material Glands conforming to BS EN 50262 or BS 6121-1 can be made of the following materials: metallic; non-metallic (e.g. nylon); composite (i.e. comprising both metallic and non-metallic parts, or coated parts). NOTE In the case of
45、metallic glands, the composition of the sealing system is not taken into account in the classification. Thus, a metallic gland with a non-metallic seal would be classified as metallic rather than composite. Metallic glands should be used where electrical continuity or high impact resistance is requi
46、red. Non-metallic glands should be used if a lightweight gland is required, or to avoid the need for a separate earth connection to the part of a metallic gland which protrudes inside a non-metallic enclosure. Composite glands should be used for applications in which it is necessary to guard against
47、 particular risks such as electrolytic corrosion and/or chemical attack. Metallic glands made of unplated steel should not be used in wet conditions. Non-metallic and composite glands should not be used where electrical continuity is required. A metallic gland should only be used with a metallic enc
48、losure if: the combination of the metallic enclosure and the gland would not give rise to electrolytic action; or the gland is plated. If the combination of the materials in the cable and the gland would give rise to electrolytic action then a metallic gland with plated components should be used. Al
49、ternatively, if no electrical continuity is required between the gland and any metallic layers of the cable, a composite gland may be used. In case of doubt, advice should be sought from the gland manufacturer. 5.4 Selection according to mechanical properties 5.4.1 Cable retention and anchorage other than retention of armoured cable (cable glands only) If the cable is prevented by external means from being pu
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