Cable Pulling Methods.pdf

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TITLE: TITLE:

Engineering Specification

RECOMMENDED:

RECOMMENDED: K. K. McRoberts McRoberts NO: NO: 1 1 REV:REV:

APPROVED: C.

APPROVED: C. S. S. Malone Malone P. P. Eng. Eng. OFOF REV.

REV. DATE: DATE: 2008-12-032008-12-03

GCS0004

1515 11

XLPE CABLE INSTALLATION

15kV, 28 kV, 1000V AND 600V CABLES

See Hydro Ottawa’s Web site for the See Hydro Ottawa’s Web site for the Latest rev

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REVISION SHEET

Revision Description Date Initial

0 Original Document 2002-09-30 km/csm. 1 Sections added / Corrected Table 3-3 metric

SWBP RWU table added / 5-2 Ref. to

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TABLE OF CONTENTS PAGE

1.0 INTRODUCTION... ... 4

2.0 REFERENCE... ... 4

3.0 SCOPE ... 4

4.0 CABLE PULLING METHODS ... ... 4

5.0 PREPARATION ... 5 6.0 LUBRICANT... ... 5 7.0 CABLE PULLING... ... 6 7.1 ONEWAYPULLIN... ... 6 7.2 ONEWAYFEEDIN... ... 8 7.3 TWOWAYPULL... 9

7.4 AFTER THEPULL... 10

8.0 CABLE IDENTIFICATION ... 10

9.0 CABLE TRAINING ... ... 10

10.0 CABLE RACKING ... ... 11

11.0 SECONDARY SERVICES ... ... 11

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1.0 Introduction

This specification covers the installation of primary voltage, 15kV & 28kV XLPE cables ranging from 1/0 AWG aluminum/copper conductor through to 1000 kcmil aluminum conductor and 600V secondary aluminum triplex cables ranging from 1/0 AWG aluminum to 500 kcmil aluminium/copper which comply with Hydro Ottawa Engineering Specification document number GMS0005 and GMS0008. These cables shall be installed in a concrete encased duct and manhole system, or a direct buried duct system. For cable pull in duct, the cable-duct configuration shall be determined/approved by Hydro Ottawa.

2.0 Reference

Hydro Ottawa - ECS0002: 120/240V Underground Residential Meter Socket

Hydro Ottawa - GCS0012: Electrical Underground Distribution Plant Identification U/C Hydro Ottawa - GMS0005: Underground Secondary

Hydro Ottawa - GMS0008: Underground Primary XLPE Concentric Neutral Cable

Hydro Ottawa - UTS0004: Single – Phase Padmount Transformer 2.4kV-16kV – Secondary Wiring Detail

Hydro Ottawa - UTS0005: Single – Phase Padmount Transformer 2.4kV – 16kV – Primary Wiring Detail

Prysmian – Handling and Installation Excerpt from Prysmian’s Wire and Cable Engineering Guide

3.0 Scope

This specification covers how Hydro Ottawa and its contractors are to install underground cables for Hydro Ottawa as well as maximum pulling tensions and sidewall bearing pressures.

4.0 Cable Pulling Methods

Cable that cannot be pulled in manually shall be installed by means of a cable puller, an electric winch or a winch on a radial boom derrick. In each case, the machine operator shall have access to a means of determining the pulling tensions on the cable (e.g. gauges which indicate direct line pressure or gauges which indicate hydraulic pressure which can be converted to line tension via a conversion table or a dynamometer). Cable pulling with trucks, backhoes or any other method whereby the amount of pulling tension is not measurable, is unacceptable.

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5.0 Preparation

First, establish the direction of the pull based on safe pulling tensions, sidewall bearing pressure calculations and minimum bending radius for a Hydro Ottawa specific cable to be installed; see Appendix A Tables 5-1, 5-2, 5-3, 5-4, 5-5A & 5-5B.

Based on the safe pulling tension, determine if the cable pull requires a basket grip or a pulling eye attached to the conductor; see Appendix A Table 5-1. Basket grips or pulling eyes shall be attached to the pulling rope or cable by an appropriate sized swivel head.

Rod each duct with an appropriate size brush and mandrel to ensure ducts are properly fitted and they are clean and free of all dirt, stones, scale, water etc.

For installation in conduit, place cable guides wherever necessary to avoid abrasion and/or damage to the cable e.g. when guiding the cable from the reel to the duct mouth or trench, when passing through or exiting manholes, when exiting a duct run. Cable guides shall be in the form of large diameter, smooth-surfaced free turning sheaves or rollers. They shall be designed to ensure that cable will not ride off the end of the roller or be pinched into a sheave contour. Guide tubes or chutes may be used provided they have a smooth burr-free working surface, well flared entrances, largest possible bending radius and are securely fastened so that the cable passes smoothly over them. In any case, equipment shall be installed to ensure the minimum-bending radius of the cable is not exceeded; see Appendix A Tables 5-5A & 5-5B.

Using suitable reel mounting equipment, locate and position the reels such that cable tension at the feeding end is minimized.

Select pulling equipment, which can provide smooth speed control at the anticipated tensions. Ensure the pull rope or flat line has the required tensile rating. Avoid the use of elastic materials.

6.0 Lubricant

Pre-lubricate duct runs or setup lubrication points along the duct run (e.g. feed in point, manholes etc to reduce pulling tension and abrasion to the cable jacket). For long heavy pulls, pre-lubrication of conduit and pull rope is essential to prevent abrasion at the bends, particularly plastic conduit bends, which can become softened due to frictional heating. In the case of long duct lengths or excessive curvatures in the duct the cable may have to be pulled in from two directions.

The recommended amount of lubricant is depended on the size and length of the conduit system into which the cable is being pulled. Typically, a ratio of 6.4 liters of lubricant per 100 linear meters of 100 mm PVC duct would be used.

Hydro Ottawa will accept water-based Bentonite Clay lubricants. Compounds containing oils or greases are not acceptable since they can adversely affect the cable jacket. The following chart provides a list of pulling lubricants, which are acceptable to Hydro Ottawa. Lubricant not shown on this chart, shall not be used without prior approval by Hydro Ottawa.

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TABLE 6-1 Cable Pulling Lubricants

Product Trade Name Manufacturer

Polywater J American Polywater Corporation Cable Glide CRC Industries

7.0 Cable Pulling

Poly rope is not to be used for any mechanical pulling (e.g. conductor/winch line, overhead or underground). Poly rope stretches when subjected to high tension and can create a hazard. Manual pulling (by hand) using poly rope is allowed.

When using a mechanical means to complete a pull, (e.g. capstan, collapsible wheel, clutch-able capstan, boom, vehicle), a Samson rope or equivalent, flat line, shall be used, as it does not stretch in the same way that poly rope does, and presents less of a hazard.

Provide two-way voice communication and adequate resources at both feeding and pulling ends of the run and at any interim location (e.g. manhole). Apply pulling lubricant liberally during the cable pull.

To minimize back reel tension accelerate slowly and smoothly from rest to a constant pulling speed of approximately 30 m/minute. Avoid stopping the pull midway through the installation; the drag due to friction is greatly increased when pulling is restarted.

Record dynamometer readings at frequent intervals during each pull.

7.1 One Way Pull In

Position the pulling equipment at the pulling manhole or transformer base. Set up equipment to maintain the minimum-bending radius of cable being pulled. See example in Figure 7-1 and Figure 7-2.

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Figure 7-1 Pull End Setup for XPLE cable – Transformer Base

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7.2 One Way Feed In

Position the cable reel so that the cable can be handfed into the manhole. When possible the cable shall be pulled off the reel by hand to reduce pulling tensions; see Figure 7-3 and Figure 7-4.

Figure 7-3 Reel End Setup for XPLE cable – Transformer Base

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7.3 Two Way Pull

Position the cable reel near the center of your pull and pull required cable one way according to all tension guidelines and pertinent specifications; see Figure 7-5.

Figure 7-5 Initial Setup for 2-way Pull

Back reel cable length required for pull in other direction on debris free ground or a tarp in a coil formation, large enough to not exceed minimum cable bending radius; see Figure 7-6.

Figure 7-6 Back reel cable in a coil formation

Position puller at pulling end and begin pulling. Maintain slack loop of cable at feed end into duct structure; see Figure 7-7.

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Figure 7-7 Final Setup for 2-way pull

7.4 After the Pull

Seal the ends of the installed cable and the ends of unused cable remaining on the reel, pending splicing or terminating, to prevent ingress of moisture.

Observe the minimum-bending radius when training cable into final position. Secure cables to manholes, riser poles, etc., as per Hydro Ottawa Engineering Specifications. Provide suitable mechanical protection during project construction for exposed cables.

8.0 Cable Identification

All cables shall be identified as per Hydro Ottawa specifications GCS0012, UTS0004, UTS0005, and ECS0002.

9.0 Cable Training

At transformer bases and primary pedestals, primary cables shall be trained from the bottom of the base to the elbow insert. Care should be taken in order to install elbow compression connectors with the proper turn to fit the insert, cables are not crossed or tangled with adjacent cables. Freedom of movement for energized switching operations is essential; see Hydro Ottawa Engineering Specification UTS0005.

Secondary cables shall be trained from the bottom of the transformer base to the secondary bus of the transformer with care taken to ensure cables are not crossed and do not cause a downward force on the transformer bus bars; see Hydro Ottawa Engineering Specification UTS0004.

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10.0 Cable Racking

Hydro Ottawa shall determine the cable racking method and location to be used. Cables in manholes and switchgear bases shall be racked along the wall of the structure using Hydro Ottawa approved tray and support system. The minimum bending radius of cables shall not be exceeded; see Appendix A Table 5-5A & 5-5B.

11.0 Secondary services

Secondary cables are to be pre-installed to lot lines staked up to a suitable support (1 m onto private property with a minimum 2 m of cable tail) and their ends sealed with Self-Amalgamating Polyethylene (SAPP) tape to prevent the ingress of moisture.

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APPENDIX A (con’d)

Table 5-2 Maximum Cable Pulling Tensions

Secondary Voltage Cables, 600V, XLPE Insulation

Maximum Pulling Tension

Basket Grip Pulling Eye

Single Cable Pull* Single Cable Pull** Conductor Size & Type

Pounds Kilograms Pounds Kilograms

1/0 AWG Aluminum URD 1,690 767 1,690 767 3/0 AWG Aluminum URD 2,000 907 2,684 1,217 250 Kcmil Aluminum URD 2,000 907 4,000 1,814 500 Kcmil Aluminum URD 2,000 907 8,000 3,629

* Tensions are for 1 basket grip per triplexed cable ** Tensions are for 1 pulling eye per conductor

Table 5-3 Maximum Cable Pulling Tensions

Secondary Voltage Cables, 1000V RWU

Maximum Pulling Tension

Basket Grip Pulling Eye

Single Cable Pull* Single Cable Pull** Conductor Size & Type

Pounds Kilograms Pounds Kilograms

2 AWG RWU Copper 1458 660 1458 661 2/0 AWG RWU Copper 2000 907 2928 1328 4/0 AWG RWU Copper 2000 907 4654 2111 350 Kcmil RWU Copper 2000 907 7700 3493 500 Kcmil RWU Copper 2000 907 11000 4990

* Tensions are for 1 basket grip per triplexed cable ** Tensions are for 1 pulling eye per conductor

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Table 5-4 Maximum Sidewall Bearing Pressure

Primary Voltage Cables, PVC Jacket, XLPE Insulation

Sidewall Bearing Pressure Conductor Size & Type

Lbs/Ft of Bend Radius Kg/m of Bend Radius

1/0 AWG Copper 1,160 1726 1/0 AWG Aluminum 845 1258 2/0 AWG Aluminum 1,065 1585 500 Kcmil Copper 2,000 2976 500 Kcmil Aluminum 2,000 2976 750 Kcmil Aluminum 2,000 2976 1000 Kcmil Aluminum 2,000 2976 URD Aluminum 1200 1786 RWU Copper 1200 1786

Table 5-5A Minimum Bending Radius (MBR) During Installation*

Primary Voltage Cables, XLPE Insulation

Conductor Size & Type Minimum Bending Radius (mm)

Minimum Bending Radius (inches) 1/0 AWG Copper, 15 kV 354 14 1/0 AWG Aluminum, 28 kV 411 16 2/0 AWG Aluminum, 28 kV 433 17 500 Kcmil Copper, 15 kV 506 20 500 Kcmil Aluminum, 28 kV 564 22 750 Kcmil Aluminum, 28 kV 634 25 1000 Kcmil Aluminum, 28 kV 698 27

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Table 5-5B Minimum Bending Radius (MBR) Permanent*

Primary Voltage Cables, XLPE Insulation

Conductor Size & Type Minimum Bending Radius (mm)

Minimum Bending Radius (inches) 1/0 AWG Copper, 15 kV 236 9 1/0 AWG Aluminum, 28 kV 274 11 2/0 AWG Aluminum, 28 kV 289 11 500 Kcmil Copper, 15 kV 337 13 500 Kcmil Aluminum, 28 kV 376 15 750 Kcmil Aluminum, 28 kV 423 17 1000 Kcmil Aluminum, 28 kV 465 18