07-30160342-DC.pdf
a Date: 21 May 2007 Origin: National Latest date for receipt of comments: 31 August 2007 Project no.: 2006/03505 Responsible committee: FSH/12/4 Automatic operation of fire protection Interested committees: FSH/12, FSH/18, FSH/18/2 Title: Draft BS 7273-3 Code of practice for the operation of fire protection measures Part 3 : Electrical actuation of pre-action watermist and sprinkler systems. Supersession information: If this document is published as a standard, it will supersede BS 7273-3:2000, which will be withdrawn. If you are aware of any other current standard that might be affected, please notify the committee secretary (contact details below). WARNING: THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 31 August 2007. This draft is issued to allow comments from interested parties; all comments will be given consideration prior to publication. No acknowledgement will normally be sent. See overleaf for information on commenting. No copying is allowed, in any form, without prior written permission from BSI except as permitted under the Copyright, Designs and Patent Act 1988 or for circulation within a nominating organization for briefing purposes. Electronic circulation is limited to dissemination by e-mail within such an organization by committee members. Further copies of this draft may be purchased from BSI Customer Services, Tel: +44(0) 20 8996 9001 or email ordersbsi-global.com. British, International and foreign standards are also available from BSI Customer Services. British Standards on CD or Online are available from British Standards Publishing Sales Limited. Tel: 01344 404409 or email bsonlinetechindex.co.uk. Information on the co-operating organizations represented on the committees referenced above may be obtained from the responsible committee secretary. Cross-references The British Standards which implement International or European publications referred to in this draft may be found via the British Standards Online Service on the BSI web site http:/www.bsi-global.com. Direct tel: 020 8996 7164 Responsible Committee Secretary: Mr John Fisher (BSI) E-mail: john.fisherbsi-global.com Draft for Public Comment Head Office 389 Chiswick High Road London W4 4AL Telephone: +44(0)20 8996 9000 Fax: +44(0)20 8996 7001 Form 36 Version 6.1 DPC: 07/30160342 DC Licensed Copy: London South Bank University, London South Bank University, Sun Jun 17 07:01:10 GMT+00:00 2007, Uncontrolled Copy, (c) BSI b Introduction Your comments on this draft are welcome and will assist in the preparation of the consequent British Standard. If no comments are received to the contrary, this draft may be implemented unchanged as a British Standard. 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Further information on submitting comments and how to obtain a blank electronic version of a comment form are available from the BSI web site at:http:/www.bsi-global.com/British_Standards/Getting_involved/DPCs/instructions.xalter http:/www.bsi- global.com/en/Standards-and-Publications/Current-work/DPCs/ Template for comments and secretariat observations Date: xx/xx/200x Document: ISO/DIS xxxxx 1 2 (3) 4 5 (6) (7) MB Clause No./ Subclause No./ Annex (e.g. 3.1) Paragraph/ Figure/Table/ Note (e.g. Table 1) Type of com- ment Comment (justification for change) by the MB Proposed change by the MB Secretariat observations on each comment submitted 3.1 Definition 1 ed Definition is ambiguous and needs clarifying. Amend to read . so that the mains connector to which no connection . 6.4 Paragraph 2 te The use of the UV photometer as an alternative cannot be supported as serious problems have been encountered in its use in the UK. Delete reference to UV photometer. Microsoft and MS-DOS are registered trademarks, and Windows is a trademark of Microsoft Corporation. Licensed Copy: London South Bank University, London South Bank University, Sun Jun 17 07:01:10 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 7273-3:2007 2006-03505 DPC.doc 1 Code of practice for the operation of fire protection measures Part 3: Electrical actuation of pre-action watermist and sprinkler systems DRAFT FOR PUBLIC COMMENT Please note that this is a draft and not a typeset document. Editorial comments are welcomed, but persons commenting on this draft are advised not to comment on detailed matters of typography and layout. Licensed Copy: London South Bank University, London South Bank University, Sun Jun 17 07:01:10 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 7273-3:2007 2006-03505 DPC.doc 2 Contents Foreword 3 Introduction 5 1 Scope 7 2 Normative references 7 3 Terms and definitions 7 4 System design 8 5 System interface 12 6 Power supplies, cables and wiring 15 7 Commissioning and handover 15 Annexes Annex A (informative) Example of an arrangement for c.i.e. with separate e.c.d. 17 Annex B (informative) Example of an arrangement for c.i.e. with combined e.c.d. 18 Annex C (informative) Example of an arrangement for any coincidence logic provided within the c.i.e. 19 Annex D (informative) Example of an arrangement for any coincidence logic provided within the e.c.d. 20 Bibliography 21 List of figures Figure 1 Typical logic gate depiction of pre-action systems 6 Figure A.1 Example of an arrangement for c.i.e. with separate e.c.d. 17 Figure B.1 Example of an arrangement for c.i.e. with combined e.c.d. 18 Figure C.1 Example of an arrangement for any coincidence logic provided within the c.i.e. 19 Figure D.1 Example of an arrangement for any coincidence logic provided within the e.c.d. 20 List of tables Table 1 Maximum areas of coverage per point-type smoke detector to operate pre-action watermist and sprinkler systems in still air conditions 11 Licensed Copy: London South Bank University, London South Bank University, Sun Jun 17 07:01:10 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 7273-3:2007 2006-03505 DPC.doc 3 Foreword Publishing information This part of BS 7273 is published by BSI and came into effect on XX Month 200X. It was prepared by Subcommittee FSH/12/4, Automatic operation of fire protection, under the authority of Technical Committee FSH/12, Fire detection and alarm systems. A list of organizations represented on this committee can be obtained on request to its secretary. Relationship with other publications BS 7273 is published in a series of parts: Part 1: Electrical actuation of gaseous total flooding extinguishing systems; Part 2: Mechanical actuation of gaseous total flooding and local application extinguishing systems; Part 3: Electrical actuation of pre-action watermist and sprinkler systems; Part 4: Actuation of release mechanisms for doors; Part 5: Electrical actuation of watermist systems 1). Parts 1 and 2 give recommendations for the electrical and mechanical actuation of gaseous fire extinguishing systems respectively. Part 4 gives recommendations for the actuation of release mechanisms for doors. Part 5 provides recommendations for electrical actuation of watermist systems (other than pre-action watermist systems). This current part of BS 7273 provides recommendations for the electrical actuation of pre-action watermist and sprinkler systems. Recommendations for the design, installation, commissioning and maintenance of fire detection and fire alarm systems are given in BS 5839-1. Recommendations for the design, installation, commissioning and maintenance of watermist and sprinkler systems are given in DD 8489 and BS EN 12845, respectively. Information about this document This is a full revision of BS 7273-3. The principal changes from the previous edition are as follows. The scope of the standard now includes pre-action watermist systems. References have been updated. Terminology has been brought into line with related standards, particularly in relation to control and indicating equipment. Reference is made to DD 8489 and BS EN 12845. Use of this document As a code of practice, this part of BS 7273 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. 1) In preparation. Licensed Copy: London South Bank University, London South Bank University, Sun Jun 17 07:01:10 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 7273-3:2007 2006-03505 DPC.doc 4 Any user claiming compliance with this British Standard is expected to be able to justify any course of action that deviates from its recommendations. Hazard warnings CAUTION. Certain electromagnetic fields, such as those generated by radio transmitters, could potentially trigger the charging of pre-action watermist and sprinkler systems or cause them to malfunction. In such cases it is appropriate to take action to minimize the risk of unintentional charging of the pipework due to the electromagnetic field radiated by such apparatus. Specialist advice should be sought where necessary. Presentational conventions The provisions in this standard are presented in roman (i.e. upright) type. Its recommendations are expressed in sentences in which the principal auxiliary verb is “should”. Commentary, explanation and general informative material is presented in smaller, italic type, and does not constitute a normative element. Contractual and legal considerations This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Licensed Copy: London South Bank University, London South Bank University, Sun Jun 17 07:01:10 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 7273-3:2007 2006-03505 DPC.doc 5 Introduction A pre-action sprinkler system is a fire extinguishing system which consists of a sprinkler system and an electrical detection system with water held back by the pre-action valve and pressurized air in the sprinkler pipework. In the event of the operation of the electrical detection system, the pre-action alarm valve operates and allows water into the sprinkler pipework. Pre-action watermist systems work on the same principle. Two generic forms of operation exist: type A and type B. Type A pre-action systems will only discharge water onto the seat of the fire when both the electrical detection system and any automatic sprinkler head or watermist nozzle has operated. Water will only enter the pipework following the operation of the detection system. Any accidental damage to the sprinklers/watermist nozzles, or pipework, will not cause water to be discharged. Type A systems are, therefore, normally used in situations in which: there is high potential for mechanical damage to the system; or the probability of mechanical damage might not be high, but the consequences of inadvertent water damage would include serious damage to sensitive contents and/or major interruption to business. Type B pre-action systems will discharge water onto the seat of a fire when any sprinkler or watermist nozzle operates, whether or not the electrical detection system has operated. However, normally the fire detection system will operate before a sprinkler head or watermist nozzle so that, in effect, the system is “wet” at the time of watermist/sprinkler operation. Type B systems are normally used in circumstances in which there is a need to speed up the operation of a dry system. The functions of the two systems can be depicted by the binary logic sequence using “and” and “or” gates as given in Figure 1. It is of importance that fire detection systems and any interfaces associated with pre-action watermist and sprinkler systems have high integrity and do not cause the pre-action alarm valve to remain closed under fire conditions. It is also important to avoid inadvertent operation of the pre-action alarm valve, as draining down of the system can be time consuming and inconvenient. The recommendations in this part of BS 7273 take these factors into account, as well as the recommendations of the relevant British and European Standards covering fire detection and fire alarm systems (BS 5839 and BS EN 54), sprinklers (BS EN 12845) and watermist systems (DD 8489). In some applications (e.g. cold stores), the consequences of inadvertent discharge are so severe that “double interlocked” pre-action systems are sometimes used. In these systems, water is only allowed to enter the pipework if both the electrical detection system and an automatic sprinkler head/watermist nozzle have operated. This differs from a type A system in that the system remains dry if only the electrical detection system has operated. Such systems are not covered in BS EN 12845 or DD 8489 and are not addressed in this British Standard. Licensed Copy: London South Bank University, London South Bank University, Sun Jun 17 07:01:10 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 7273-3:2007 2006-03505 DPC.doc 6 Figure 1 Typical logic gate depiction of pre-action systems Sprinkler ? head ? operation AND Type 1 ? sprinkler ? discharge AND Detection ? signal AND OR AND Type 2 ? sprinkler ? discharge Licensed Copy: London South Bank University, London South Bank University, Sun Jun 17 07:01:10 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 7273-3:2007 2006-03505 DPC.doc 7 1 Scope This part of BS 7273 gives recommendations for the design, installation and commissioning of electrical equipment for the actuation of pre-action watermist and sprinkler systems. It covers the interface between fire detection and fire alarm systems (see BS 5839-1) and watermist and sprinkler systems (see DD 8489 and BS EN 12845 respectively). Recommendations relating to watermist systems which do not operate in the pre-action mode are contained in BS 7273-5. NOTE Watermist systems can be used for the suppression, control and extinguishing of fires. In this part of BS 7273, the references to fire extinguishing systems relate to watermist systems of any type, as well as to sprinkler systems. 2 Normative references The following referenced 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 5839-1:20
