Remerciez-le!

Remerciez @Admin pour avoir partagé cet document gratuitement, de la manière la plus simple, en partageant sur les réseaux sociaux.

MINIMUM SEPARATIONS BETWEEN BURIED POWER AND TELECOMMUNICATION CABLES NZCCPTS I

MINIMUM SEPARATIONS BETWEEN BURIED POWER AND TELECOMMUNICATION CABLES NZCCPTS Issue 1 March 2003 CABLE SEPARATIONS GUIDE March 2003 2 The New Zealand Committee for the Co-ordination of Power and Telecommunication Systems Inc. (NZCCPTS) The New Zealand Committee for the Co-ordination of Power and Telecommunication Systems was established in 1985 following the increasing need to implement efficient cost-effective measures for the limitation of hazard and interference to Power and Telecommunication Systems and Personnel. Such measures not only require the determination of optimum engineering solutions consistent with minimum national cost, but also necessitate clear guide-lines covering the equitable allocation of responsibilities during all work phases from planning through to in-service operation. The objective of the New Zealand Committee for the Co-ordination of Power and Telecommunication Systems is to meet these needs and, by means of publications and seminars, promote a greater awareness and understanding of the action that must be taken to ensure that Power and Telecommunication Systems coexist satisfactorily. Membership of the Committee and its Working Parties currently comprises representatives from each of the following organizations: ♦ Transpower New Zealand Ltd. ♦ Telecom New Zealand Ltd. ♦ Electricity Engineers' Association of New Zealand Inc. ♦ Tranz Rail Ltd. ♦ Energy Safety Service, Ministry of Consumer Affairs For further information concerning this Committee and its published guides, contact: The Secretary Secretary as at March 2003 NZCCPTS Mike O’Brien 3 Moehau Grove Trentham Ph: 0-4-528 9117 Upper Hutt 6007 Fax: 0-4-528 9116 New Zealand Email: hazelmichael.ob@paradise.net.nz March 2003 3 GUIDE ON MINIMUM SEPARATIONS BETWEEN BURIED POWER AND TELECOMMUNICATION CABLES Published and issued by: The New Zealand Committee for the Co-ordination of Power and Telecommunication Systems Inc. (NZCCPTS) 3 Moehau Grove Trentham Upper Hutt 6007 NEW ZEALAND Issue 1 March 2003 ISBN 0-473-07379-X March 2003 4 Foreword This document provides industry guidelines on the minimum separations that should apply between buried power and telecommunication cables. Comments for revision of this guide are welcomed. Any comments or information that may be useful should be forwarded to: The Secretary Ph: 0-4-528 9117 Mike O’Brien Fax: 0-4-528 9116 NZCCPTS Email: hazelmichael.ob@paradise.net.nz 3 Moehau Grove Trentham Upper Hutt 6007 New Zealand “The information contained in this booklet has been compiled by the NZCCPTS for the use of its members from sources believed to be reliable, but neither the NZCCPTS nor any of the contributors to this booklet (whether or not employed by NZCCPTS) undertake any responsibility for any mis-statement of information in the booklet, and readers should rely on their own judgement or, if in doubt, seek expert advice on the application of the guidelines to work being carried out.” March 2003 5 Contents 1. Introduction 1 2. Minimum Separations between Buried Power and Telecommunication Cables 2 3. Application Rules for the Above Minimum Separations 3 Appendix A Issues Taken Into Account in Determining Minimum Separation Values 4 1. Background 4 1.1 Hazard from Contact with Power Cables 4 1.2 Hazard from Contact with a Neutral Screened (or Armoured) LV Power Cable 4 1.3 Hazard from Contact with an LV Power Cable that is not Neutral Screened or Armoured 5 1.4 Hazard from Contact with an HV Power Cable 5 2 Practical Issues 5 2.1 Service Trench Separations 5 2.2 Road Reserve Separations 6 2.3 LV Neutral Screened Power Cable 7 2.4 LV Power Cable that is not Neutral Screened or Armoured 7 2.5 HV Power Cable 8 2.6 Crossings 8 3 Electrical Noise Induction 8 March 2003 6 1. Introduction This document provides industry guidelines on the minimum separations that should apply between buried power and telecommunication cables. This supersedes the separations in the national "industry agreement" between Telecom and the Electricity Supply Association of NZ, that has applied for the last sixteen years. The basic minimum separations are summarised in the following table. However it is important to also read the Application Rules associated with this table to understand how these separations should be applied, and what exceptions to these separations are permitted. A discussion paper explaining the reasons behind these minimum separations is included in this document as Appendix A. Specific requirements for burying power cables are contained in AS/NZS 3000 Wiring Rules, Section 3.11 Underground Wiring Systems. These include minimum depth, the need for a warning marker tape, bedding requirements and mechanical protection requirements. 2. Minimum Separations between Buried Power and Telecommunication Cables At Crossings On Parallel Runs In Road Reserve (see Section 3 Rule (4)) Voltage and Cable Type With Protection Without Protection Separation in Shared Trench (any direction) or Separation when Cables are Vertically Apart Separation when Cables are Horizontally Apart (NOT in a Shared Trench) Service Lead Into House LV neutral screened or armoured 50mm 150mm 150mm 300mm Same as “In Road Reserve” EXCEPT FOR residential urban undergrounding projects, where 0mm is permitted for neutral screened cables if the requirements of Section 3 Rule (3) are met. LV not neutral screened or armoured 50mm 450mm 450mm 600mm Same as "In Road Reserve" HV 150mm 450mm 450mm (2.4km limit on length) 600mm Same as "In Road Reserve" March 2003 7 3. Application Rules for the Above Minimum Separations (1) Unless otherwise specified, the above minimum separations can be applied horizontally, vertically, or in any other direction. However, future access to the power cable will be much more difficult if the telecommunications cable is laid directly above the power cable. For similar reasons, pad mounted power plant (e.g. distribution transformers, 11kV ring main units) should not be installed above telecommunications cables. In the road reserve, where different horizontal and vertical separations apply, separations in directions other than horizontal or vertical should be a proportionate combination of the horizontal and vertical minimum separations (sH and sV respectively). i.e. V H s s s       − +       = 90 90 90 θ θ θ where θ = angle to vertical (in degrees) of direction of separation (2) The minimum separations between buried power and telecommunication cables on parallel runs apply regardless of whether protection (e.g. plastic slabs) is installed over the power cable. (3) For residential urban undergrounding projects, the 150mm/300mm separation from "LV neutral screened or armoured" cables on parallel runs can be reduced to a "nil" separation for service leads into houses, provided: (i) the power cable serves an urban residential property (ii) the power cable is 230V single phase neutral screened cable (iii) the power cable is protected by an HRC fuse (or similarly fast acting protection) (iv) the telecommunication cable is in a continuous sub-duct (no joints), with a (sub-duct) insulation rating in excess of the highest voltage present in the power cable (v) the length of parallel, at this reduced separation, is < 50m. Note: • This reduced separation does not apply to 230V single phase armoured, unscreened cables. • The 150mm/300mm minimum separation is still required in the road reserve. (4) All the above are minimum separations between buried power and telecommunication cables. An extra allowance of 150mm has been included when using these separations on parallel runs in the horizontal, or mostly horizontal, plane (i.e. both the power and telecommunication cables are at approximately the same depth), to account for the fact cables can never be laid at exactly the specified offset, and hence guarantee maintaining the minimum separation (this will also facilitate future installation of joints in the power or telecommunications cables). This does not apply to shared trenches, where both cables can be clearly seen so that the minimum separation can be maintained at all times. (5) Protection must be such that spades, picks (and some diggers) will not "cut" through the protection slab above the power cable, without the operator realising he had "hit" something and stopping - before also hitting the power cable beneath the protection slab. Protection must be installed as detailed in AS/NZS 3000 Wiring Rules, clause 3.11.3.3. The installation of the telecommunication cable and/or power cable in a PVC pipe does not constitute "protection", unless the pipe has equivalent mechanical properties to a 'heavy duty' duct (PVC or PE) as defined in AS/NZS2053:1995. March 2003 8 The purpose of protection slabs is to protect the power cable from being "cut". As such, they should be installed in the horizontal plane immediately above (and within 75mm of) the power cable, and overlap each side of the power cable by at least 40mm. Whether it is between the power and telecommunication cables is irrelevant. To ensure the protection slab does not "skew", the bedding material must first be placed alongside and above the power cable and "tamped down", to provide a firm flat horizontal base to lay the protection slab on. (6) All the above minimum separations can be reduced to 0mm separation to allow any type of power cable to be buried directly alongside a concrete telecommunication pit or manhole that is accessible (i.e. “visible”) from above ground. (7) Where a power cable is installed directly under a telecommunication plastic pit and is covered by suitable mechanical protection (see (5) above), uploads/Management/ separations-guide.pdf