Explain in detail the steps that must be taken to ensure that the task is carried out safely (include drawing and sketches where required, include pre commencement of work activities and the work itself in a chronological manner)
A. Verify IFC drawings availability
B. Verify Documents for QC material receiving inspection
C. Mobilization of equipment
D. Transport of materials loading & Unloading
E. MV Cable Pulling
MEDIUM VOLTAGE CABLE PULLING / LAYING PROCEDURE | METHOD STATEMENT
PURPOSE
This Method Statement / Procedure covers the work method and procedure for Medium Voltage Cable Laying / Pulling to be
carried out in Waad Al Shamal Integrated Solar Combined Cycle Power Plant Project. This method was prepared as
guideline for effective enforcement of work thus; construction personnel have to determine the applicability and
feasibility of this MS in accordance to approved construction drawing, cable specifications and site condition.
REFERENCE DOCUMENTS
• Contract Agreement
• Project Technical Specifications
• Applicable/ Approved International Standards
• Issued For Construction Drawings
• Manufacturer’s Instructions
DEFINITIONS AND ABBREVIATIONS
• IEC International Electro-Technical Commission
• NEMA National Electrical Manufacturers Association
• RSI Request for Site Inspection
• MRR Material Receiving Report
• NCR Non-Conformity Report
REFERENCES
• IEC International Electro-technical Commission
• NFPA 70/NEC National Fire Protection Association/ National Electric Code
• IEEE Institute of Electrical and Electronic Engineers
383 type test of class IE electric cables
1202 Flame testing of cables for use in cable trays.
RESPONSIBILITY
• Site Manager — Determine all requirements needed in order to comply with contractual requirements and safety
standards.
• Construction Manager – Lead all construction activities and enforce strict adherence to all project requirements.
• Electrical Superintendent — Ensure that work once started is carried out as planned and that the applicable
standards are complied with. Check working methods and precautions to be taken by the supervisors/foreman
before commencing work.
• Field Engineer — Ensure that all related works are carried out in accordance with approved Issued for
Construction drawings, specifications, schedule, quality and safety. Report to Construction Manager.
• Supervisor / Foreman — Supervise all field installations. Reports to Electrical Superintendent
• QC Inspector — Shall be responsible for conduction surveillance and inspection duties for work and ensuring
quality compliance and efficient recording and reporting of results if required. He shall review all relevant
documents, material conformance certificates and non-conformance reports. Prepares Request for Site Inspection.
• Safety Manager/Officer — Ensure that HSE plan is being implemented and monitored.
METHODS AND GENERAL GUIDELINES FOR MEDIUM VOLTAGE CABLE PULLING/LAYING
General Requirements
• Cables in ducts. Ducts and slots in concrete slabs shall be checked to ensure that they are free from obstructions
before cables are drawn in. Where draw-pits are present each one shall be given a unique identifier which shall be
included on all layout drawings. Lubricants or materials used to assist with drawing cables into the ducts or to seal
the ducts after the cables have been drawn in shall have no detrimental effect on the cable sheath.
• Cables in Concrete Trenches. Power cables of different voltage levels should not be installed on the same tray or
ladder rack. MV Power cables should not be installed on the same tray or ladder rack as control cables. Where
trays or ladder racks are installed on both sides of the trench, a walkway space shall be allowed down the centre of
the trench.
• Cable routing and segregation. All cables shall be installed to have adequate clearance from other services. Cables
shall generally be routed to avoid hot and fire-risk areas, and to minimize the risk of damage from any external
heat source. The layout of all cables shall be arranged to have adequate clearance from other services
• Instrument and control cables as well as the cables of the Communication Systems must be laid sufficiently apart
from the MV power cables so that no interference will occur and the transmission of fault signals is excluded.
• Minimum separations shall be observed between above defined levels for assurance against electromagnetic
interference:
• Where control cables are required to be run along the same route as one or more power cables, the control cable
tray should be routed underneath the MV power cable tray
• To enable complete redundancy to be maintained, two separate routes shall be used for the data highway and all
other redundant circuits. Redundant cables shall take two distinct paths, when not routed in duct banks.
• The data highway routes shall be separate from MV power cable routes.
• The power and control cable systems of each individual generator unit or station auxiliary system shall be
routed along a different path from other unit or station auxiliary systems. The cable installation shall be
unitized and a single common route along the full length of the turbine hall shall be avoided.
• Routes plans shall be checked for all underground cables. The plans shall accurately show the location of the
cables, including road crossings and underground services in the vicinity of the cables. Permanent markers
shall be provided on both sides of road crossings.
• Cable risers near gangways or in electrical rooms that are exposed to possible mechanical damage are to be
protected.
• Enclosed vertical and horizontal runs of cables are provided with fire stops to limit the spread of fire, and shall
be sealed to prevent “chimney effects”. Wherever cables
• In areas where there is a possible risk of oil or other combustible material falling onto cable trays and ladder
racks the trays and ladder racks shall be mounted in the vertical plane.
• The cabling of the fire detection and alarm system, emergency lighting systems, and other equipment required
in the event of fire shall be carried out using fire resistant cables.
Cable Handling and Preparation
Field engineer and supervisor shall check approved issued Construction drawing, cable route plan and cable list.
Field engineer and supervisor shall check at site the completion of the following cable route as shown in the construction drawing:
• Cable trench
• Duct bank and conduit
• Cable tray installation
• Sections and details
Ensure that a worksite location has been released and ready for safe work execution. Cable installation will be
carried out by technically qualified and competent personnel. Cable continuity and insulation test of cable will
be checked before cable pulling activity. After cable test, insulation test equipment (meg-ohm meter) must be
discharged and cable cores must be grounded to discharge any induced voltage.
Check for separation of cables as per voltage classification and approved Construction drawing.
Clean cable duct before cable pulling by blowing using air compressor, appropriate mandrel and wire brush.
Cable pulling supervisor and foreman shall organize the cable pulling plan which includes the following:
• Cable schedule/pull sheets review
• Cable drum schedule
• Measurement of cable to be pulled
• Location of cable reel/drum
• Lifting of cable reel and placing at cable stand
• Placing of cable rollers
• Pulling machine preparation, for large cable
• Number of person and each positions
• Communication devices to be used are established
• Cable basket, winch and rope to be used (cable pulling at trench and conduit)
• Preparation of scaffold for cable pulling at height
• Preparation of miscellaneous materials
• Cable tag/wire identification installation
• Barricades and warning signs are in place.
• Both sides of each duct bank shall be protected to avoid falling material such as stones, etc. on cables
Handling of cables. The following shall be considered during handling and unloading of cable.
• Cable reel should be handled in accordance with manufacturer’s instruction and cable handling procedure
• Cable reels should be handled on edges of flanges only (not on flat side of flanges)
• Reels shall be chocked during transporting to prevent damage from load shifting
• Cable reel must not be placed where they would impede personnel
• Cable reel shall not be dropped. Ensure that lifting equipment and material are inspected and in good condition.
• A void cable reel over sharp edges.
• Cable reel should be located on hard surfaces and avoid sinking into soil during handling.
• Cable reels should be rolled in accordance with roll directional arrows labeled on reel flanges
• When fork lift handling, reel flanges will be cradled between the fork tines, and should touch flange edges at all four points
Cable drum must be transported from stockyard to site location. Roadway for unloading location must also be check due to any on-going construction activity on road
FIGURE A. TRANSPORTATION
FIGURE B. HANDLING AND STORAGE
Cable Pulling
Refer to cable schedule and verify in actual site condition the measurement required for cable pulling from starting
point to end point. Cable pulling report shall be filled up and submitted to document controller for master file.
Cable reel/drum location will be identified through site inspection and will be shown in cable pulling route drawing.
Cable reel/drum stand:
• Cable drum shaft and trolley
• Cable stand will be used for uncoiling of cable during pulling
• Cable stand shall be checked as per capacity and requirement of cable reel/drum
• Cable stand shall be check for good condition, and shaft shall meet the capacity requirement of cable reel/drum
• Movable parts will be checked for free willing and grease will be applied as needed
• Use steel plate base for cable stand to avoid sinking at the ground.
Transport cable to designated area. Insert shaft in the flange, lift the cable drum and place in the cable stand. Check
the correct roll direction of cable.
When rollers are to be used, ensure that cable rollers are installed and secured with appropriate space. Use cable roller
intended for long bend and offset route of the cable (heavy duty corner roller). Cables must not be in contact with
surfaces which can damage external sheath.
Communication devices shall be established before and during cable pulling activity.
Cable pulling at duct bank/road crossing:
• Where cable was to be pulled in a conduit, ensure that the conduit was clean and free from debris.
• Apply approved lubricant during pulling of the cable.
• Cable shall be protected against abrasive surfaces and edges during pulling at conduit with appropriate side roller
During Manual Cable Pulling and Handling:
• All workers shall wear complete PPE and shall follow the agreed instruction and safety procedure in cable
pulling initiated by their supervisor.
• Supervisor/foreman shall have adequate person to pull the cable
• Persons will be assigned at the cable drum location for its rotation and feeding of cable, at cable bend, at pull
boxes, at cable ends and at any intervals needed as per work condition.
• If wire rope and basket will be used for cable, check and secure for tightness. Swivel will be fitted to avoid
twisting of cable and damage to the external sheath.
• Provide protection to cable for any edges and abrasive surfaces
• Establish a good coordination and clear instruction while pulling the cable to avoid incidents in loosing of
grips, cable drop or caught between
• Cable route shall be checked when cable was hard to pull, it should be easily pulled avoiding excessive tension
• Cable can be flaked to avoid any jam or twisting when cable needs to be pulled to succeeding route.
During Cable Pulling by Winch:
• Pulling machine/puller winch which will be used for this activity shall be inspected and checked for good
condition.
• Always refer to manufacturer’s instruction and safety manual of pulling machine. Machine shall be operated
by competent person.
• Safety Check and Precaution
• Review and follow approved Safety Job Hazard Analysis
• Review and recheck material requiring certification
• Working area must be cordoned-off and use warning sign to limit access only for operator and allowed
personnel.
• Supervisor and foreman shall designate person’s position at cable route. Personnel for cable pulling shall
thoroughly check cables during pull, cable rollers and cable reel. There shall always be assigned person in each
corner route, cable reel, in the pulling machine and at end side.
• Prepare cable basket and winch cable. Cable basket size shall be appropriate to diameter of the cable.
• Ensure that basket and winch cable/rope for pulling is secured and tight. Ensure that cable basket and winch
cables were free from damage.
• Check for any loose object and connection in the potential path whipping back of a rope/winch cable after failure under tension.
• Swivel connector will also be connected to prevent winch cable from twisting.
• Avoid excessive bending of the cable.
• Cable shall be pulled in a constant speed; avoid excessive tension during straight and in corner pull.
• When excessive tension was observed, pulling should be stopped and check cable path for any obstruction.
Also check that cable rollers were freely rotating, cables entering duct were properly lubricated, edges and
offsets were checked and cables were in proper slope
• Care shall always be taken to avoid damage on the cable insulation while pulling.
DURING CABLE PULLING ON CABLE TRAY/LADDER
• Check completeness of cable tray and visually inspect to ensure that is free from debris, burrs and sharp edges
that can damage the cable. Put insulator/rubber to protect cable from edges of the cable tray. Verify allowable
space for laying of cable on tray/ladder.
• Cables that is to be installed on tray shall be laid neatly in parallel runs with no crossing over of cables except
as approved by the Client
• Cables shall be fixed to the ladder with cable ties threaded through the slots in the ladder rungs. Cable shall be
tied on ladders run horizontally with rungs horizontal and on vertical ladder or ladder run horizontally with
rungs vertical (on edge).
• Cables installed on cable tray must be fixed with cable tie.
• Smaller cables may be tied in groups. After cable ties have been ‘zipped’ tight, the ends shall be trimmed and
the cut ends removed as part of site cleanup
• When positioning cables on the tray, proper separation shall be maintained between
control/instrument/communications cables and MV power cables run on the same ladder.
• Cables must leave the tray through the rungs and not over the side rail.
CABLE PULLING FROM CONDUIT
The following cables should not be run in the same conduit or duct:
• Cables of different voltages
• Cables of more than three wire sizes
• Cables for ac and de circuits
• Cables for power and control/instrumentation/communications
Conduit runs shall be completely assembled, swabbed through to remove any foreign debris prior to cable pulling.
Care shall be taken during pulling of cable in conduit to minimize friction between the cable and the conduit
A recommended lubricant can be used to reduce friction.
Where a cable enters a conduit or duct, provision shall be made to prevent the ingress of water or other liquids by
glanding or sealing with glued heat shrink.
INSPECTION
QC Inspection
All inspections shall be coordinated by QA/QC Inspector, who will implement the inspection program and notify
all parties involved in advance of the scheduled dates of inspection to enable them to participate. Insulation resistance
test and high potential test will be applied according to vendor’s recommended test voltages and testing procedures.
Cable shall be inspected and tested (pre-installation and pre-commissioning requirement) using approved forms.
Internal and preliminary inspection shall be done before submittal to Contractor for Final Inspection. Verify and
check that cable installation complies with project specification, cable schedule and approved construction drawing.
RSI will be raised for inspection once work and internal inspection was completed.
Relevant records shall be signed by all the required parties and originals kept by the QA/QC Department.
Acceptance criteria for inspection will be within Project specification and standards. Required actions will be taken
place as per site work condition for remarks and punch lists noted during inspection and testing.
As-Built Drawing
Document controller will be responsible for maintaining a complete set of Construction drawings, Material Take-off
(MTO) and Data sheets dedicated for up-to-date marked-up of any actual field changes to the drawing issued or any
revisions.
Once the scheduled area/portion is completed, foreman will inform the supervisor for any changes in the approved
drawings.
The Supervisor makes “As-built” drawings in Master Copy immediately after completion of works (“As-built” – any
changes in the approved drawings, P&ID
and specifications marked in red according to actual constructed condition)
and submits to field engineer who will review and forward the As-built Drawings to QA/QC department
After QA/QC department reviewed and verified it, the gathered “As-built” red-marked drawings submitted by
Construction will be processed for submittal to client and a Master copy will be kept by CGA document controller.