LIVE WORKING MANUAL WORK ON OVERHEAD LINES THE HOT STICK METHOD

Transcription

1 1. SCOPE This Section of the Power Systems Live Working Manual details the procedures to be followed when HV overhead lines require to be worked on Live using Hot Stick Working techniques. The procedures apply the principles established by the Electrical & Mechanical Safety Rules (Electrical and Mechanical) 4 th Edition to achieve Safety from the System and in particular Specialised Procedure SP3. 2. ISSUE RECORD DATE Issue No. AUTHOR AMENDMENT DETAILS June 1996 DLWM 5.2 Issue A A Rae Initial issue. March 1997 DLWM 5.2 Issue B J Smart Update. September 1998 PSLWM 5.2 Issue C R J McGill Revised to change Distribution to Power Systems. February D D Kilday Updated for ferroresonance and changes to pole shrouding policy also included - 72 pages. 3. ISSUE AUTHORITY Author Owner Issue Authority David Kilday Senior Standards Engineer Jack Neilson Operational Compliance Manager William Cuthbert Business Risk & Safety Manager _ SP Power Systems Limited PSLWM 5.2

2 4. CONTENTS Page No. 1. SCOPE ISSUE RECORD ISSUE AUTHORITY CONTENTS DEFINITIONS ASSESSMENT APPLICATION OF SAFETY RULES & GENERAL SAFETY Authorisation Live Line Tools and Equipment General Safety Precautions TRAINING & AUTHORISATION OF STAFF ORGANISATION, CONTROL & OPERATION OF HV LIVE WORKING Introduction Procedures Organisation Control of HV Hot Stick Working Operation of HV Hot Stick Working TOOLS & EQUIPMENT Approval Marking Numbering & Recording Testing & Care Use of Tools & Equipment Assessment of Safe Working Loads _ SP Power Systems Limited PSLWM 5.2

3 11. PROCEDURES FOR WORK ON OR NEAR HV OVERHEAD LINES Procedure WL Procedure WL Procedure WL Procedure WL Procedure WL Procedure WL Procedure WL _ SP Power Systems Limited PSLWM 5.2

4 5. DEFINITIONS 5.1 Terms printed in bold type are as defined in the ScottishPower Safety Rules (Electrical and Mechanical) 4 th Edition. 5.2 For the purposes of this section of the Power Systems Live Working Manual the following definitions apply: HV Live Working The carrying out of work of any kind on Live High Voltage overhead lines, using Approved tools and equipment. HV Hot Stick Working The carrying out of work on Live HV overhead lines from an Approved Insulated Scaffold or where appropriate a pole, using tools and equipment Approved for the purpose. 6. ASSESSMENT 6.1 All work on or so near Live exposed HV conductors that Danger may arise requires assessment before the commencement of work to ensure that Danger will not arise during the course of the work. This assessment will be carried out by the Authorised Person who is to undertake the work. In all cases, however, as part of the assessment, Apparatus shall be subjected to a routine inspection prior to the start of any work to ensure that Danger will not arise due to the condition of the Apparatus. Should this inspection reveal any significant deficiency in the Apparatus which would prevent Approved procedures being applied effectively, no attempt shall be made to work on the Apparatus whilst it is Live. 6.2 Ferroresonance is a phenomenon of instability produced by a particular combination of circuit elements. A ferroresonant circuit may be formed when a cable and a transformer (with a load of less than 3% of its rated capacity) are simultaneously energised or de-energised one phase at a time. An example of energising or deenergising one phase at a time is making/breaking jumpers using outage free techniques. The resultant power frequency overvoltage can be up to four times the applied voltage. This overvoltage will start when the first phase is energised/deenergised and will persist until the switching on all phases is complete. Power frequency overvoltage surges of this magnitude will cause deterioration of the cable insulation and the transformer winding insulation and may lead to faults. Surge _ SP Power Systems Limited PSLWM 5.2

5 arresters will protect the transformer and the cable from the overvoltage. However, due to the length of time that the surges are on the system, thermal run-away may occur within the arrester blocks. Thermal run-away will lead to a catastrophic failure of the arrester. When using outage free techniques, the overhead network should be assessed for the possibility of ferroresonance. Where making or breaking jumpers will affect a transformer that is within 700m of an HV cable, a ferroresonant circuit may be set up. In order to prevent ferroresonance from occurring, the jumpers must be connected or disconnected within ten seconds. This can be achieved using either: an Approved portable air-break switch or Approved make and break tools. 7. APPLICATION OF SAFETY RULES AND GENERAL SAFETY The Safety Rules for HV Hot Stick Working are as stated in SP3 of the ScottishPower Safety Rules (Electrical and Mechanical) 4 th Edition. This section of the Power Systems Live Working Manual gives guidance on the application of the Safety Rules and outlines general safety topics. 7.1 Authorisation The Approved Procedures referred to in SP3 are those Approved for inclusion in this section of the Power Systems Live Working Manual by the Engineering & Transmission Operations Manager, Power Systems Division. HV Hot Stick Working shall be carried out in strict compliance with these procedures To comply with SP3.1(i) an Approved procedure may only be used by a team, every member of which will be suitably trained and Authorised according to one of the following categories:- WL1.SS1 As a member of a Live working team to carry out and supervise Approved HV Hot Stick Working procedures. WL1.SS2 As a member of a Live working team to carry out Approved HV Hot Stick procedures under the Personal Supervision of a WL1.SS1 Authorised Person An HV Hot Stick Working team will consist only of Authorised Persons, one of whom shall be LL1 Authorised. Before any HV Hot Stick Working commences one WL1.SS1 Authorised Person must be nominated as being in charge. All HV Hot Stick Working must be carried out under his Personal Supervision. _ SP Power Systems Limited PSLWM 5.2

6 7.2 Live Line Tools and Equipment To ensure compliance with SP3, Sub-Section 10 of this Section lists the tools and equipment Approved by the Engineering & Transmission Operations Manager, Power Systems Division which will be used for HV Hot Stick Working and details a numbering and recording system and a testing and maintenance procedure. 7.3 General Safety Precautions The General Safety Precautions detailed in SP3 must be complied with HV Rubber gloves shall be used at the discretion of the linesman or when specifically called for in a procedure Safety helmets of Approved type must be worn at all times by all members of the team when working on Live Lines. Any Person in the close vicinity of the team must also wear an Approved safety helmet Before any HV Live Working commences, the auto-reclose feature applied to that circuit at the point of work shall, where it is practicable to do so and with the consent of the Control Person, be rendered inoperative. The method of achieving this shall ensure one shot to lockout operation in the event of a fault at the point of work Where it is not practicable to render auto-reclose features inoperative, the Control Person shall be notified The use of HV Hot Stick Working procedures shall be restricted to favourable weather conditions. Adverse weather conditions include mist, fog, snow, thunder and lightning and where the wind is such that control of Live Line tools is adversely affected. Work may continue in light rain at the discretion of the Person in charge of the team, except in those procedures in which ropes are used in close proximity to Live conductors In the event of adverse weather conditions arising, the work shall be made safe as quickly as possible with the conductors either in their normal positions or securely held by HV Live Working equipment. Work shall not recommence until the adverse weather conditions have passed. Where work is suspended through adverse weather arising or darkness overtaking the work, the conductors shall be made safe as above and the Control Person informed immediately. Before recommencing work, the HV Live Working equipment shall be shaken to remove droplets of water and sticks wiped dry using a clean cloth or chamois leather. _ SP Power Systems Limited PSLWM 5.2

7 Where they are in contact with Live conductors the sticks shall be wiped within the handling zone only. HV rubber gloves shall be worn for this operation All work shall be subject to a preliminary consideration by the linesman in charge to ensure that it may be safely accomplished by HV Hot Stick Working procedures and that the safe working loads of the tools and equipment will not be exceeded. (Sub-Section 10.5 of this Section). HV Hot Stick Working procedures involving displacement of conductors shall not be used if the line conductors to be worked on are damaged or are jointed with mid-span joints other than the compression type in the spans on either side of the point of work Where conductors are displaced from their normal positions, safe clearances between conductors and between any conductor and the ground or other object shall be maintained No pole that is badly decayed, or damaged, shall be climbed. The only Procedures that may be carried out on a decayed or damaged pole are WL1.140 (Jumper cutting) and W1.41 (pole replacement). In these cases, work must be carried out from replacement poles or from Approved scaffolding Before commencing HV Hot Stick Working on lines rated up to 11.5kV any unearthed steelwork shall be tested by the application of the Approved crossarm proving device. If the steelwork is found to be Live, Safety Distance shall be measured from the lowest unearthed steelwork. If it is found to be not Live, Safety Distance many be measured from the lowest Live conductor. On lines rated above 11.5kV, if there is reason to suspect that unearthed steelwork may be Live, Safety Distance shall be measured from the lowest unearthed steelwork. In all other cases unearthed steelwork shall be earthed with the Approved earthing carriage following which the Safety Distance may be measured from the lowest Live conductor Before displacing conductors Approved insulated shrouding should be applied to crossarms and stay tops All poles on which work is to take place shall be fitted with a red marker band at the Safety Distance. No Person shall allow any part of his body to pass above the marker band. The Safety Distance is specified in SP.3 and shall be measured from the lowest Live conductor or unearthed steelwork as stated in paragraph above. _ SP Power Systems Limited PSLWM 5.2

8 During the progress of work, the marker band may, on the instruction of the person in charge, be removed or repositioned to indicate the new working limits. Before the marker band can be removed or repositioned it may be necessary to remove earth bonding from steelwork at different levels on the pole HV Hot Stick Working Procedures involving conductor displacement shall not be used on any pole with over-running earthwire, under-running earthwire or catenary wire Wood poles erected under Live Lines in preparation for HV Live Working shall be shrouded in accordance with relevant procedures in this Manual, and shall be so erected as to be 0.15m clear of Live conductors. They shall never be left in constant contact with Live conductors Adopting the Procedure WL1.140 jumpers can be cut and removed to create points of Isolation prior to work proceeding under Permit for Work conditions PSMSP 1.4 gives dispensation for work to proceed without the issue of a Safety Document on specific items of Apparatus where they have been disconnected by HV Live Working Procedure WL1.140 to create points of Isolation and provide Safety Distance. The specific items are: (a) (b) (c) (d) (e) Pole mounted auto reclose circuit breakers Pole mounted auto sectionalisers Air-break isolating switches Pole mounted HV fuse units Pole mounted transformers The work shall be assessed and Approved by a Senior Authorised Person Whilst moving conductors supported by HV Live Working equipment, the operating linesmen shall at all times be prepared to lock the wire tongs in their saddles should a dangerous situation seem likely to arise. No conductor shall be moved on wire tongs unless the safety pins are in place on the wire tong saddles, lever lifts and rope snubbing brackets In the event of a conductor being "lost" whilst handling with wire tongs, the operating linesmen shall immediately loosen their grip on all Apparatus and lean back in their safety harnesses. _ SP Power Systems Limited PSLWM 5.2

9 This will reduce to a minimum the effects of any voltage gradient down the pole. In recovering a conductor the utmost caution must be exercised even though the conductor may have fallen on to insulated shrouding. In case of doubt, additional wire tongs shall be used to recover the conductor. Failing this the Control Person must be notified with a view to making the line not Live for the recovery of the conductor When working at the pole top after the conductors have been removed, operators shall position themselves and the equipment to give optimum clearance from the conductors on either side Before any Live conductor is cut, all tension must be removed from it and the conductor is obviously slack. The conductor on each side of the cut must be securely held to prevent reduction of clearances to other Live conductors or equipment once the cut is made Limitation of current, which may be broken by conductor cutting as specified in Procedure WL1.140, must be observed All pieces of binding wire, stirrups and other debris shall be collected and removed from the site on completion of the work. 8. TRAINING AND AUTHORISATION OF STAFF 8.1 SP3.1(ii) states that "all staff engaged on HV Hot Stick Working shall have received appropriate training and shall possess written Authorisation for HV Hot Stick Working from the Company". 8.2 Linesmen engaged on HV Hot Stick Working require to be appointed and trained as laid down in SP3.1 and Authorised in writing in accordance with PSMSP 5.1. They will therefore require to be thoroughly conversant with the requirements of the Safety Rules (Electrical & Mechanical) 4 th Edition and trained in the Approved Procedures and the practical and safe use of Approved tools. 8.3 Although engineers generally require no formal training in HV Hot Stick Working they need to appreciate the possibilities, limitations and general philosophy of HV Hot Stick Working. _ SP Power Systems Limited PSLWM 5.2

10 9. ORGANISATION, CONTROL AND OPERATION OF HV LIVE WORKING 9.1 Introduction Live Working as a general term covers work on High Voltage overhead lines with the conductors Live, which may take one of three forms known in nationally agreed terminology set out in A.C.E. Report 14 (1967), as, (i) Hot Stick Working, (ii) Bare Hand Working and (iii) Live Line Tapping. Bare Hand Working and Live Line Tappings are not Authorised for use in Power Systems, Scotland. 9.2 Procedures This section of the Manual contains the Approved Procedures for Hot Stick Working to be used in ScottishPower and shall be referred to as HV Hot Stick Working Specialised Procedure SP3 of ScottishPower Safety Rules (Electrical and Mechanical) 4 th Edition contains the Safety procedures for work on Live High Voltage Overhead Lines up to and including 33kV. SP3.1(i) states "No HV Hot Stick Working shall be carried out except in accordance with Approved procedures" To comply with SP3.1 (i) this Section of the Live Working Manual details the Approved Procedures which are issued by the Business Risk and Safety Manager on behalf of the Managing Director, Power Systems Division and must be strictly adhered to. 9.3 Organisation The number of persons in a team is dependent on the Procedure being undertaken and shall include at least one WL1.SS1 Authorised Person Transport shall be suitable for carrying, in a secure manner, the equipment required to accomplish the Procedures to be carried out. 9.4 Control of HV Hot Stick Working The Control Person shall be responsible for the recording of work carried out Live using HV Hot Stick Working techniques in accordance with OPSAF (PSMSP 5.2). _ SP Power Systems Limited PSLWM 5.2

11 9.5 Operation of HV Hot Stick Working Jobs to be done by HV Hot Stick Working methods will accumulate from line inspections and construction requirements The Linesman in charge of the HV Hot Stick Working shall make the final decision on site that all conditions are suitable before work commences. 10. TOOLS AND EQUIPMENT 10.1 Approval The Engineering & Transmission Operations Manager, Power Systems Division, must approve all tools and equipment for HV Hot Stick Working in accordance with the Approved Equipment Register Marking Numbering and Recording A clear mark in the form of a red band shall be applied and maintained on every Approved HV Live Working tool or piece of equipment where appropriate, indicating limits of safe handling as detailed in SP Each tool shall be identified by a serial number. The number will be prefixed by a code and will be permanently stamped on the metalwork A record card will be kept for each tool and shall contain the following details: (i) (ii) (iii) (iv) (v) The tool number The name or trademark of the manufacturer. The tool type reference or description. The safe working load (SWL) as specified by ScottishPower. The date of manufacture, year and month (if possible). The cards will be used for recording inspection dates and remarks. The cards will be filed in a suitable container and kept beside the HV Live Working tools. _ SP Power Systems Limited PSLWM 5.2

12 A suitable card format is produced below: MANUFACTURER: LIVE LINE EQUIPMENT RECORD DESCRIPTION: SERIAL NO. \ \ DATE COMMISSIONED: S.W.L. \ TENSION COMPRESSION MECHANICAL AND/OR ELECTRICAL INSPECTION/TEST DATE TYPE CONDITIONS FOUND AND ACTION TAKEN INITIALLED 10.3 Testing and Care Introduction The Safety Rules set out the responsibility for ensuring that tools and equipment are in good condition before use This Section of the Live Working Manual deals with the care and maintenance required for the different types of tools and equipment used in HV Live Working to ensure that they are kept in good condition All tools and equipment must be clearly numbered and recorded as laid down in Sub-Section 10.2 of this Section Epoxiglas sticks shall be electrically tested with an Approved tester at 6 monthly intervals, alternately with E.A. Technology test trailer or Approved equivalent and an Approved portable test set. Details of the test shall be entered on the appropriate record card The mark, which is on all appropriate HV Hot Stick tools indicating limits of safe handling, shall be checked and maintained at 6 monthly intervals. _ SP Power Systems Limited PSLWM 5.2

13 All tools, slings, rope blocks and other items of equipment which are required to take mechanical loading shall be tested and/or inspected on a 6 monthly basis and details of the test/inspection entered on the appropriate record card. Certain items of equipment used for HV Live Working are subject to statutory insurance inspection. These are separately recorded in a Lifting and Handling Register and include rope blocks complete with ropes, slings, draw vices, lifting gins and channel anchors Additionally all tools and equipment shall be inspected for signs of mechanical damage before and after each operation. A damaged tool or piece of equipment must never be used Storage and Transportation All tools and equipment, specifically for HV Hot Stick Working shall be stored in a suitable place. The facilities in the store shall allow for removal of individual tools with them being kept apart to prevent mechanical damage. Heating to provide a warm dry atmosphere and air circulation shall be provided for the HV Hot Stick tools and equipment in storage The Epoxiglas sticks must be transported in a vehicle adapted to prevent mechanical damage to the sticks Epoxiglas Sticks Epoxiglas sticks must never be over-stressed mechanically since the safety of operating personnel is dependent on their condition. Should a stick be accidentally over-stressed it shall be rendered permanently unusable and must be replaced. If a stick is scratched it shall be marked as damaged until it has been repaired and tested or replaced. If a stick is scratched such that the stranding is undamaged the mechanical strength of the stick will be unaffected but the electrical performance may be adversely affected. If a stick is scratched or scored such that stranding is broken the mechanical strength of the stick will be affected and it shall be rendered permanently unusable and must be replaced. _ SP Power Systems Limited PSLWM 5.2

14 These sticks are resistant to moisture but must nevertheless be kept as clean and dry as possible Before use, each stick must be wiped down with a soft dry cloth The sticks must never be laid directly on the ground. Racks are provided for laying the sticks out on site and waterproof sheeting is provided for laying equipment on After use the sticks shall be dried and burnished with a soft cloth before being returned to storage The high gloss finish on the surface of the tools must be maintained. At regular intervals the tools shall be thoroughly cleaned with an Approved cleaner to remove all traces of dirt or previous coatings of wax. The tools should then be wiped down with a soft cloth and a thin coating of wax polish applied to the entire surface. They should then be burnished with a feltless cloth until a high gloss is obtained Scratches on Epoxiglas sticks must be repaired as soon as possible using an Approved restorer in accordance with the instructions provided If any Epoxiglas stick or part of a stick fails the Approved test it shall be withdrawn from service until it has been cleaned, restored and successfully re-tested Metal Fittings The metal fittings on Epoxiglas rods shall be kept clean and moving parts properly lubricated with an Approved lubricant Wire tong saddles shall be inspected for wear on the chains and clamping devices. The wing nuts should be kept free and lightly lubricated with an Approved lubricant. The clamping surfaces should be kept free from grease or oil and regularly cleaned with an Approved cleaner to minimise slip on the rods Rope blocks shall be inspected for wear on both sheaves and swivels properly lubricated with an Approved lubricant. _ SP Power Systems Limited PSLWM 5.2

15 Ropes Polythene ropes used for HV Live Working must be stored out of direct sunlight to avoid colour deterioration. They shall be kept free from contamination and abrasion damage Natural fibre ropes e.g. Manila shall be kept clean and free from damage and shall be replaced if suspect Insulated Scaffolding Scaffolding for HV Hot Stick Working shall be used and maintained in compliance with the relevant sections of ScottishPower Procurement Specification 1376/10,002. It shall be kept clean at all times. The Epoxiglas sticks making up the scaffolding shall be inspected and maintained in the same way as the sticks in the tool kit. However they shall not require to be electrically tested Approved Cleaners (i) (ii) AB Chance Cleaning Kit White Spirit Approved Lubricant Light machine oil e.g. 3-in-1 oil or equivalent Approved Wax Polish DL Shell wax 1128/28943 available in 3.5 kg tubs from Wilkons/Campbell, Bulennia works, West Drayton, Middlesex Tel Use of Tools and Equipment Tools and equipment shall only be used for a purpose detailed in this Section and in a manner described in the Procedures Section. _ SP Power Systems Limited PSLWM 5.2

16 Conductors Moving and Supporting Tools Wire Tongs These are Epoxiglas rods in various lengths from 6 feet to 16 feet, and diameters from 1½ inches to 3 inches with an adjustable clamp jaw operated by rotating the rod. These tongs are used for supporting, manoeuvring and laying off Live conductors clear of the working area. They have a swivelling shackle at the butt end for attachment of a sling, rope block or lever lifts Wire Tong Saddles Aluminium alloy saddles are used for attaching wire tongs to the line supports. The wood pole type is attached to the pole by a quick acting chain and lever arrangement that incorporates a safety pin device to prevent accidental release. The saddles have clamps that allow the tongs to slide or to be securely held. Where extra clearance is required, extension saddles are used Lever Lifts These are used in place of wire tong saddles to provide a nonslip fixing at the lower end of the tong where limited movement in line with the tong is acceptable. They are attached to the pole by a quick acting chain tightener and safety pin device foot. Auxiliary Crossarm The 9 foot Auxiliary Crossarm, complete with fork wireholders and fork wireholder insulators, is used as part of a rig to change poles, steelwork or insulators Wire Tong Block Clamps These are of a similar construction to the clamp associated with the wire tong saddle. When attached to the tong they are used as a fixing for rope blocks where necessary Insulator Link Sticks These are short Epoxiglas rods fitted with a safety hook at one end and a swivelling shackle at the other. Insulator link sticks are designed for use under tension in series with ropes or rope blocks that cannot be considered to have insulating properties. _ SP Power Systems Limited PSLWM 5.2

17 Roller Link Sticks These are Epoxiglas rods fitted at one end with a positive locating roller in an adjustable locking gate and at the other end with a swivelling shackle. They are used to exert a lateral pull on conductors or jumpers to give added clearance Cum-a-long-Clamps The Approved type for HV Live Working is the Klein wire grip. This is placed on the line by an appropriate HV Live Working stick. An automatic gate prevents the clamp from falling from the line Rope Blocks HV Live Working rope blocks are Gibbs type tufnol blocks reefed with polythene rope. They are normally 3 and 2 type Crossarm Pulley Anchor This is a steel or aluminium alloy clamp that fits to the crossarm and provides anchorage on both sides for rope blocks etc Insulated Hand Tools Tie Sticks This is an Epoxiglas rod fitting with a rotary blade at one end and a universal fitting at the other. It is used for binding and unbinding conductors Universal Stick This is an Epoxiglas rod fitted with splined universal connectors at both ends and used in conjunction with a range of attachments Grip-All Clamp Stick This is a general purpose Epoxiglas hand tool fitted with a ring type jaw operated by a ratchet slide on the butt. It is used for the general lifting and handling of accessories. _ SP Power Systems Limited PSLWM 5.2

18 Wire Holding Stick This is an Epoxiglas hand tool fitted with an adjustable conductor clamp operated by a slide lever. It is used for holding and positioning conductors and tails during conductor cutting and compression operations Lever Wire Cutters This is an Epoxiglas hand tool fitted with a cutting head; rod operated by a side lever and normally used for cutting light conductors, binders etc All Angle Cog Wrench An Epoxiglas rod fitted with an adjustable angular head suitable for the attachment of standard socket spanner fittings and operated through cogs by rotating the tool handle. It is used for the insertion and removal of nuts and bolts in the vicinity of Live conductors Insulated Plier Handles These provide insulated extensions to plier or wire cutter handles when such tools need to be used on or near a Live line Tools for Use with Universal Sticks Fixed Head This is used to loosen or pack up binding wires. number of "V" notches for this purpose. It has a Rotary Prong This is a rotating finger or prong also employed for binder work and for the fitting and removal of cum-a-longs and rope blocks etc. on or near Live conductors Adjustable Insulator Fork This is an adjustable fibre claw for holding and positioning disc insulators. _ SP Power Systems Limited PSLWM 5.2

19 Security Clip Pusher This is a dual-purpose tool used for pushing out security clips on strain insulators with a curved end for forcing the clips into position again Security Clip Inserter This tool is used for inserting "W" clips where these have been pushed out or have fallen out of strain insulators on Live lines All Angle Fuse Puller A versatile adjustable holding and gripping tool used for fuses, shrouding, insulators etc Inspection Mirror "Mirror and stick" inspections is no longer an authorised procedure in ScottishPower Conductor Cleaning Brush Hacksaw This is used for the removal of oxide, etc. from conductors before making joints, tappings, etc. Separate brushes must be used for copper and aluminium conductors. This is a standard hacksaw frame fitted with a universal attachment. When this tool is used, goggles must be worn Pinholder This tool grips the heads of pins or bolts up to approximately 16mm diameter to allow insertion near Live lines Snap-Out Split-Pin Remover A spring arrangement on this tool facilitates pulling out splitpins Split-Pin Installing Tool This tool grips split-pins for insertion on Live equipment. _ SP Power Systems Limited PSLWM 5.2

20 Ratchet Wrench Head This tool allows bolts to be tightened or loosened using a standard socket spanner Flexible Wrench Head This fits standard socket spanners and its flexibility allows use at limited angles Skinning Knife This is used for cutting or scraping insulation or cleaning conductors Hammer Head Where a forceful blow is required near Live conductors, this 1lb. hammer head can be used. It can also be used to detect pole top rot with the line Live Binder Head This tool is for use with a binder dispenser for rebinding Live conductors on pin insulators. It is made from a blank chuck with a steel rod inserted at right angles Tie Applicator Ring Head This tool is for applying and removing helical fittings that tie conductors to pin insulators Tie Pad Applicator Head This tool is for applying the pad onto a conductor where it sits on a pin insulator before application of helical ties Other Tools For Use In Contact With Live Conductors Insulated Hanger This tool, installed on a Live conductor, allows safe parking of Live Line taps during installation and disconnection of jumpers and load make-and-break tools. _ SP Power Systems Limited PSLWM 5.2

21 Chafe Tape Winder This tool is for the application of chafe tape to Live conductors. It is mounted on and fixed to the conductor by a clamp stick. Separate winders should be used for copper and aluminium tapes to prevent contamination Binder Dispenser In conjunction with the binder head this tool facilitates the binding of Live conductors to pin insulators Make-and-Break Tool An Approved "make and break" tool shall be used during all jumper connecting or disconnecting operations. The maximum load that can be made or broken using a make or break tool without arc-suppression is 50A. Where an Approved make or break tool with arc-suppression is used, a maximum load of 185A may be broken. The arc-suppression tool is used also where there is a possibility of ferroresonance, irrespective of load. The tool without arc-suppression operates on the expulsion fuse principle to break load and can be tripped at will by the operation of a trigger. Loads can be made and carried by the closing of a knife switch that is mounted in parallel with the fuse unit. The Approved arc-suppression make and break tool is fault rated at 6kA for 1 second. This tool can be used to break the load rapidly and there is spring assistance to make the load. This ensures that all three phases can easily be broken or made in less than 10 seconds and ferroresonance is eliminated. It is recommended that make and break tools are used a minimum of 1 span away from poles with surge arresters connected to them. In certain circumstances, this will not be possible, in these instances it is acceptable to use the tools on the same pole as surge arresters Ampstick Slipon Ammeter This can be fitted to a Universal Hot Stick and used to measure current flowing in an overhead conductor. _ SP Power Systems Limited PSLWM 5.2

22 Live Line Compression and Cutting Equipment (i) Live Line Hoses 4.6m Hose - BICCON Cat. No. LL H m Hose - BICCON Cat. No. LL H (ii) Compressor Head Compressor Head - BICCON Cat. No. G10HML (iii) Cutting Head Cutting Head - BICCON Cat. No. G10CM (iv) (v) Appropriate BICCON Compression Dies Compressor For appropriate compressor for use with above equipment, refer to Sub-Section By-Pass Jumpers By-pass jumpers of 32mm 2 copper or copper equivalent aluminium flexible conductor covered with a 100mm polythene tube with the ends sealed to exclude moisture and terminating in suitable Live Line taps. They are used for bridging sections of conductors before cutting or bridging gaps in conductors before permanent closure. They may be made rigid by insertion in fibreglass or other suitable insulating tubing. The polythene or other insulating materials are not considered as insulation that would reduce minimum clearance Live Line Tapping Equipment (Fuse Operating Rods) These are sectional or telescopic glass fibre rods for fixing Live Line taps to line conductors from ground level. They may be used in conjunction with a splash plate. _ SP Power Systems Limited PSLWM 5.2

23 Ancillary Tools and Equipment Steelwork Shrouding Used to prevent accidental contact of pole-top steelwork by Live conductors, helical ties or binders during binding, unbinding and conductor handling operations. Shrouding is manufactured from glass fibre, polythene or other suitable insulating material in various shapes to suit differing pole-top configurations Rope Snubbing Bracket A bracket fitted to the pole by means of a quick acting chain tightener with safety pin device and used for securing fall ropes, rope blocks etc Insulated Platform The Approved platform is Epoxiglas approximately 250mm wide, 1.8m long with pole attachment, Epoxiglas strut and safety rail. This is used where it is necessary to work short distances out from the conductor support. This is a lifting gin which is positioned above equipment, clamped onto the support and used in conjunction with rope blocks and a pulley at the base of the support to raise and lower heavy equipment such as transformers Cross-arm Proving Device A Seaward CARL Mark 2 Cross Arm Leakage Detector (131A910) which provides a means of checking leakage current on unearthed pole crossarms on Systems up to 11.5kV. A direct earthing device is also available for lines above 11.5kV Pole Twister This device is fixed by a chain round the pole and provides a lever with which to turn a pole square with a line after erection. _ SP Power Systems Limited PSLWM 5.2

24 Anchor Pins Rope These are steel rods approximately 1.5m x 38mm which are driven in at an angle to provide anchorage for temporary stays and fall ropes from blocks. Rope used in the vicinity of Live lines shall be polythene rope, normally 3 strand 50mm. Hand lines shall be polythene 3 strand 25mm rope. For temporary stays and extensions to fall ropes attached to insulator link sticks manila rope shall be used Pole Shrouding There are two Approved methods of shrouding pole tops before erecting the poles close to Live conductors. Approved reusable pole shrouds available can be fitted at pole top or on the pole at any appropriate height. They are rated for touch contact only. On no account must Live conductors be left in constant contact with the shrouding. Bags of 1,000-gauge polythene can be used to shroud the tops of poles erected close to Live conductors. The bags shall be pulled on to the pole top over one another, folded round the pole and bound by tape. Three bags shall be used for 11kV. This is based on accidental touch contact only. On no account shall Live conductors be left in constant contact with the shrouding. Where the new pole is erected other than adjacent to an existing pole then the number of bags shall be doubled to allow for additional contact and rubbing by the conductor. In either case it is bad practice for shrouded poles to be left close to Live conductors for more than 1 week Scaffolding Scaffolding for HV Hot Stick Working comprises a system scaffold with an aluminium tube base section and up to three insulated upper sections made from Epoxiglas tubing. The scaffolding provides a platform, for carrying out work that cannot be done from a pole. _ SP Power Systems Limited PSLWM 5.2

25 Binoculars These should be suitable for preliminary examination of the pole-top fittings and conductors in the spans on either side of the pole to be worked on. A magnification of 10 x 50 is suitable Sunglasses Each member of the team must have a pair of suitable anti-glare sunglasses for protection of eyes from sunlight and from particles falling from the lines Tool Racks for Epoxiglas Rods These are galvanised steel rods with sloping arms on each side, covered with plastic to hold HV Live Working tools without damage. The rods can be driven into the ground to provide a stand for the tools Waterproof Sheets These are used for laying out HV Live Working tools and equipment on the ground Rubber Gloves HV rubber gloves as specified in DOM Portable Test Set AB Chance portable test set. For portable electrical testing of HV Hot Sticks Compressor Appropriate size of compressor. For use in conjunction with Live Line compression and cutting equipment. Examples - BICCON BP10 - CEMBRE CPE-0-P12 _ SP Power Systems Limited PSLWM 5.2

26 10.5 Assessment of Safe Working Loads General All overhead lines are erected in accordance with an Approved specification. Factors of safety must not be reduced during the HV Live Working. The methods used therefore must take this into consideration HV Hot Sticks - Material Characteristics The HV Hot Sticks are made from "Epoxiglas". "Epoxiglas" consists of thousands of epoxy resin impregnated glass fibres laid lengthways and wound around a unicellular plastic foam core. The core is impervious to water. The strength of these sticks is much greater in tension than in compression. Consequently small diameter tongs are used in tension and large diameter tongs used in compression. As a tong is loaded with compressive force a deflection can be observed. The observed deflection provides a visual guide to prevent overloading. The Safe Working Loads (Compressive) are based on a maximum tong deflection, at its mid-point, of 25mm. Tong break-up in compressive tests to destruction was observed to be of a progressive nature and started with individual strands on the surface breaking with an audible "pop". If during the course of conductors being moved on HV Live Line tongs a "pop" is heard from a stick then the movement should be stopped and reversed immediately and all saddle-clamps locked off. Two tongs in parallel should then be used if work is to proceed HV Hot Stick Working-Conductor Support In use the HV Hot Stick Working stick method of conductor support resembles a simple jib crane, the line support and two tongs forming a rigid triangle. One tong acts in tension, the other in compression. The tension tong can if necessary be augmented by use of a rope block between tong and line support. _ SP Power Systems Limited PSLWM 5.2

27 As a result of the different strengths of tongs acting in tension and compression the limiting factor on the loading of a conductor support structure is the S.W.L. of the compression tong Safe Working Loads The safe working loads of HV Live Working tools and equipment are shown in Table 1. To avoid the need in every situation to carry out an exercise to calculate the load applied on a support structure, Tables 2(a) and 2(b) have been prepared. These show the maximum wind loading span it is permitted to lift with each size of tong in compression for a given conductor. The method of calculation of these figures is shown in For the purpose of the calculation the maximum total angle of declination of the conductor on the pole top is taken as 20º. Where a span length greater than that given in Table 2(a) is required to be displaced or where a tong is noted to deflect more than 25mm at its mid point or begins to "pop" then the tong should be augmented by placing another tong of similar size in parallel with it. This method more than doubles the wind loading span which can be displaced. The maximum wind-loading span that can be displaced with two tongs in parallel is given in Table 2(b). _ SP Power Systems Limited PSLWM 5.2

28 TABLE 1 SAFE WORKING LOADS OF HV LIVE WORKING TOOLS SWL Description Tension Compression lbs. kgf lbs. kgf Wire Tongs 1½ in. x 8 ft. 1, ½ in. x 10 ft. 2,500 1,135 1, ½ in. x 12 ft. 2,500 1, ½ in. x 16 ft. 2,500 1, in. x 12 ft. >2500 >1135 1, in. x 16 ft. >2500 >1135 1, Saddles 1, , Lever Lift 1, , Snubbing Bracket (per ring) 1, Cum-A-Long 8,000 3,650 Roller Link Stick 1, Insulator Link Stick 4,000 1,825 Rope Blocks 3/2 Small 1, /2 Large 2,500 1,135 Polythene Rope 7mm mm Manila Rope (Grade 1) 9mm Cross Arm Pulley Anchor >2240 >1000 _ SP Power Systems Limited PSLWM 5.2

29 TABLE 2(a) MAXIMUM WIND LOADING SPAN FOR SINGLE TONG IN COMPRESSION Tong Size 2½ in. x 10 ft. 2½ in. x 12 ft. 2½ in. x 16 ft. 3 in. x 12 ft. 3 in. x 16 ft. CONDUCTOR WIND LOADING SPAN (METERS) H.D ,043 2,541 1,000 4,729 4,011 Stranded ,616 2, ,099 3,468 Copper , ,757 1, N/A N/A No. 6 2,375 1, ,700 3,136 No. 5 1,787 1, ,877 2,413 No * 1,709 1,381 No N/A / N/A /0 N/A N/A N/A /0 N/A N/A N/A /0 N/A N/A N/A mm 2 ACSR 1, * 2,096 1,658 Solid H.D. Copper TABLE 2(b) MAXIMUM WIND LOADING SPAN FOR TWO TONGS IN COMPRESSION Tong Size CONDUCTOR H.D. Stranded Copper H.D. Solid Copper 2 x 2½ in. x 10 ft. 2 x 2½ in. x 12 ft. 2 x 2½ in. x 16 ft WIND LOADING (SPAN METERS) * No. 3 2,630 2, No. 1 1,465 1, /0 1, * 2/ * 3/ * 4/ N/A 50mm 2 ACSR 3,323 2, Notes to Tables 2(a) and 2(b) 1 N/A - No span length which can be safely displaced with this tong. 2 * - To achieve this span length the angle of declination of the conductor at the pole top must be no greater than 15º. A method of determining the angle of declination is given in below. _ SP Power Systems Limited PSLWM 5.2

30 Calculations of Wind Loading Span for Tables 2(a) and 2(b) The loading of a conductor support structure can be considered as the resultant of the following forces: The vertically downward acting weight of the conductor in assumed level adjacent spans plus or minus the vertical component of the tension resulting from line declination or inclination at the work pole. In the worst case the total angle of declination will be 20º i.e. 10º downpull on either side of pole as limited by overhead line specification. As previously stated the conductor support structure is basically a rigid triangle. The effect on the compression tong in this structure of the vertical load produced by the conductor reaches a maximum when that tong is at an angle of approximately 15º to the vertical. If the structure loading is within safety limits at that position, all other positions of the structure will be within the safe limits. Formula W - Conductor weight in kg/m. L1 & L2 - Adjacent span lengths in metres. L3 - L1 + L2 2 T - Conductor Tension in kgf 1 and 2 - Conductor angles of inclination or declination (ScottishPower Drawing , Fig. 1) 3-1 ± 2 Total angle of declination For straight line pole with inclination/declination Vertical Force F (Conductor weight) ± (Vertical component) (acting vertically) (conductor tension) F = WL 3 ± T (Sin 1 ± Sin 2) which can be simplified in practice to F = WL 3 ± T Sin ( 1 ± 2) _ SP Power Systems Limited PSLWM 5.2

31 In worst case 1 and 2 are both 10º Therefore F = WL 3 + T Sin 20º Compressive force (b) in tong with conductor laid off at 15º i.e. worst case (ScottishPower Drawing , Fig. 2) b = COS 15º (WL 3 + T Sin 20º) If force in tong is limited to SWL of tong the equation for L 3 becomes L 3 = SWL/COS 15º - T Sin 20º W Wind Loading Span = SWL/ T W Determination of Angle of Inclination/Declination When considering angles of declination or inclination of a conductor, ignore the sag. Angle 1 and 2 are formed between a level straight line passing through the work pole conductor support and other straight lines passing through the same support and the conductor supports on adjacent poles, as shown in ScottishPower Drawing , Fig. 3. On site such angles are at pole top level within the Live conductor Danger area. Similar angles must be reproduced at or near ground level where they can be safely measured. The ground level sight lines can be reproduced by using standard fibreglass fuse operating rods fitted with a hook. When doing so, it is assumed that the conductor height above each of the crossarms on the three adjacent poles is the same. When a section is involved adjust levels accordingly. Start at the work pole. alongside the line pole. Hang the fibreglass rods from the crossarm At eye level or other selected level place apply a wrap of yellow or white tape around the pole. Tape the rod at the same level. _ SP Power Systems Limited PSLWM 5.2

32 Hang the rods from each adjacent pole crossarm in turn and tape the poles at level of the tape on the rods. It is then necessary to adjust the levels found to compensate for the off laid conductor position. If the conductor will be uplifted by, say, 1m the work pole PVC band should be lifted 1m or, alternatively, both adjacent pole bands should be lowered 1m. If hedges or the like obstruct intended sight lines all bands can be equally lifted. Measurement of 1 and 2 can then be done by using an Abney level. The Abney level is a simply constructed instrument for measuring angles under field conditions. It has a centre zero degree scale fixed to a sighting tube with a small hole at one end and a wire sight at the other. Part way along the tube and to one side is a fixed mirror set at 45º to the tube sight line. A fast and finely adjustable pointer arm that moves on the degree scale is fitted with a vernier and magnifying lens for accurate reading. A spirit level is fixed to this arm at 90º to the pointer arm centre line. This adjustable spirit level and fixed mirror arrangement allows the horizontal bubble to be seen in a vertical plane alongside the object being sighted. By simultaneously sighting an object, say a pole top or a pole at ground level, and adjusting the instrument until the bubble on its zero line coincides with this object the angle of inclination or declination between a level line passing through the instrument and the object sighted can be read on the instrument scale. To measure the angle hold the Abney level at the height of the PVC band on the work pole, and sight the PVC band on the adjacent pole. Adjust level until bubble coincides with sighted band. Read angle 1, in degrees from Abney scale. To obtain 2 repeat as above but sight on the PVC band on the other adjacent pole. _ SP Power Systems Limited PSLWM 5.2

33 _ SP Power Systems Limited PSLWM 5.2

34 11. PROCEDURES FOR WORK ON OR NEAR HV OVERHEAD LINES 11.1 Procedure WL Installation of By-pass Jumpers Scope of Procedure This Procedure covers the methods and precautions to be followed when using temporary by-pass jumpers to bridge sections of conductor, switches etc. Approved by-pass jumpers consist of 32mm² copper or copper equivalent aluminium flexible conductor covered with a 100mm polythene sleeve, having the ends sealed to exclude moisture. The jumpers terminate in suitable Live Line taps and can be up to 6.5 metres long Safety Precautions The polythene sleeve-covering jumper braiding must not be considered as an insulator When a by-pass jumper is being installed, or is in use, the Safety Distance from it must be maintained at all times. Adequate clearance between the jumper and any steelwork must be maintained During erection or removal of by-pass jumpers, there is a possibility that one end of the jumper may inadvertently be released when the other end is in contact with a Live conductor. Adequate safety precautions must be taken to prevent the lost end coming into contact with Earth, or infringing Safety Distance to working personnel During erection and removal of any by-pass jumper, only one Live Line tap at a time shall be connected or disconnected. No attempt shall be made to connect or disconnect both ends simultaneously No load currents shall be made or broken with a by-pass jumper. Prospective load currents to be broken may be measured with an Approved HV ammeter (installed in a substation or fitted to a Universal Hot Stick) or estimated from transformer full-load capacity. Load current must only be made or broken using either: an Approved portable air-break switch or the appropriate Approved make and break tools. The maximum load which can be made or broken using a make and _ SP Power Systems Limited PSLWM 5.2