Equipment Advisory

Adv. No. 2015-020 R1 Supersedes: R0

Issue Date: Aug 19, 2015 File: 1613.9.1

Information Bulletin: Duct Spacers and Warning Boards for PVC Duct

Revision Note Revised text in this advisory since the previous revision is shown with a vertical bar in the margin: changed or added text is underlined, and deleted text is crossed-out. Revisions in the drawings are encircled with a cloud-shape, and a number in a small triangle indicates the revision edition.

1.0 Items Covered ES54 H1-01 URD AND UD INSTALLATIONS

H1-07 INSTALLATION AT REDUCED DEPTH OF COVER H2-03 CONCRETE ENCASEMENT 5" DUCT H4-01 DUCT CLEARANCES TO OTHER UTILITIES

2.0 Overview Distribution Standards are implementing a new construction practice for the assembly and installation of underground PVC duct for distribution infrastructure. This new construction practice will become mandatory when the revised ES54 Construction Standards are published. In the interim, all new projects shall follow this Advisory and the attached draft ES54 standards, effective August 3, 2015.

Duct Spacers – BC Hydro Catalogue ID 96022508: In accordance with the Class of Work Specifications, the assembly of the duct bank is left up to the BC Hydro contractor. They have the discretion to implement the most suitable and economical method of assembly. In some cases, contractors have installed manufactured duct spacers, resulting in superior assembly and better quality. More frequently, contractors will use 2"x4" or other pieces of lumber, or cut 3"dia PVC duct pieces to use as vertical spacers, which are then covered in concrete. For horizontal spacing, contractors place “rakes” and then remove them following the pour of the concrete layer.

Warning Boards – BC Hydro Catalogue ID 97000676: For mechanical protection and warning of direct buried feeder duct banks, or reduced depth of burial, the BC Hydro standard practice has been to install preservative-treated lumber boards and PVC warning tape above the duct bank. However, a lumber board’s life expectancy is short, mechanical strength deteriorates quickly and a thin yellow warning tape is difficult to see when excavating.

This Advisory is for the information of personnel working on BC Hydro’s distribution equipment, and is not for public distribution. Page 1 of 4

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

Adv. No. 2015-020 R1

The new construction practice described herein is based on installing industry standard, impact-resistant polyethylene warning boards. New boards have been developed to perform both functions: mechanical protection for feeder direct buried duct banks, or reduced depth of burial, as well as a visible warning for a cable duct installation presenting an electrical hazard.

For further reference on product evaluation and field trials, refer to ETR051 (http://edmbchwiki1/dist/standards/images/3/31/ETR051_Duct_Spacers_Final.pdf).

3.0 Action BC Hydro stores now carry PVC duct spacers and marker boards as standard stock items 96022508 and 97000676 respectively.

Duct Spacers: For concrete-encased duct banks, BC Hydro designers shall follow the draft ES54 Section H standards and include new PVC type duct spacers. For customer installed concrete-encased duct banks, with customer supplied 5" PVC duct, the customer design shall show and the customer shall install the same IPEX PVC type duct spacer 5W20-2.

Warning Boards: For direct-buried feeder duct banks or reduced depth of burial, BC Hydro designers shall follow the draft ES54 Section H standards, which show a warning board. For direct-buried URD and UD duct banks, warning boards may be installed as selected by the BC Hydro Designer at locations where a high safety hazard is identified by a risk assessment. For customer projects, warning boards can be obtained from LineStar Supply Inc. (www.linestar.ca) located at 4-8125 130th St., Surrey, BC, V3W 7X4 or contact Tony Kuhlman Ph. 604.594.2701 F. 604.594.2751 C. 604.374.3413

Class of Work Specifications 1322 and 1323 will be revised shortly to include duct spacers and warning boards for new construction projects.

Projects currently in progress may proceed with a duct installation per the approved project design.

This Advisory is for the information of personnel working on BC Hydro’s distribution equipment, and is not for public distribution Page 2 of 4

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

Adv. No. 2015-020 R1

4.0 Figures

Figure 1 – IPEX 5W20-2 Duct Spacer for 5" dia. PVC Duct

Figure 2 – Warning board Figure 3 – Direct burial

This Advisory is for the information of personnel working on BC Hydro’s distribution equipment, and is not for public distribution Page 3 of 4

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

Adv. No. 2015-020 R1

Figure 4 - Duct spacer locking tabs Figure 3 - 5" Duct spacers

5.0 Distribution Standards Contact

Name: Mark Kelvin email : mark.kelvin@bchydro.com

Phone #: 778-452-6844 Cell # : 604-220-3905

6.0

Date: 2015-08-18 Date: 2015-08-18

This Advisory is for the information of personnel working on BC Hydro's distribution equipment, and is not for public distribution

Page 4 of 4

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:DEC 2000ORIGINALLYISSUED: JUN1980

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ENGINEER OF RECORD

GENERAL TRENCHING DETAILSURD AND UD INSTALLATIONS

Notes1. Spacers shall not be used for direct buried ducts.2. For direct-buried duct bank installation, place warning tape or polyethylene marker boards,

catalogue ID 97000676, may be placed instead of treated lumber boards and marking tapeat locations with high safety hazard as determined by the BCH Designer.

Reference Standards

ES54 H0-02 Duct General NotesES54 H1-06 Duct Entry DetailsES54 H2-01 75 mm (3") Duct ES54 H2-02 100 mm (4") DuctES54 H2-03 125 mm (5") DuctES54 H2-04 ReinforcingES54 H3-01 Window Opening In Underground ChambersES54 H4-01 Clearances to Other UtilitiesES54 W1-01 Base Preparation, Backfill Material

Installation Location Min. Depth of Cover (mm)Railway 1680

MOTI Roadway 1200Other Areas 900

Direct Buried Concrete Encased

Concrete

Backfill

300

Cov

er

Warningtape or board

Finished grade

Backfill

Ducts

300

Cov

er

Warning TapeFinished grade

Base

Ducts

BaseTemporary trench shoring if required by contractor, remove before backfill

1

DRAFT

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:APR 2003ORIGINALLYISSUED:APR 2003

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GENERAL TRENCHING DETAILSINSTALLATION AT REDUCED

COVER DEPTH

1 .01

Elevation

Ducts

ManholeWarning platesB

Chy

dro

Sidewalk or road

Plan

BC

hydr

o

BC

hydr

o

BC

hydr

o

A_

Manhole

3000MAX

Warning platesBCH Cat ID: 96017849

Min

imum

sta

ndar

d co

ver

< M

inim

um s

tand

ard

cove

r

Min

imum

sta

ndar

d se

para

tion

Other utilities orany otherobstructions

6000 MAX

300

Alternativewarningboards

Warning tape

Finished grade

Rebar: 10M, L=900 mm

Ducts concreteencased

Warning plate

70C

over

Section A_ 2

Detail 1

Detail 1_

_DRAFT

Aug 17

, 15

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:APR 2003ORIGINALLYISSUED:APR 2003

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M. KELVIN L. STEVANOVIC F. DENNERT

ENGINEER OF RECORD

GENERAL TRENCHING DETAILSINSTALLATION AT REDUCED

COVER DEPTH

2 .02

Elevation

Bridge

Ducts ManholeWarning plates

Bridge

BC

hydr

o

Sidewalk

Plan

BC

hydr

o

BC

hydr

o

BC

hydr

o

A1

Manhole

6000MAX

Bridgeabutment

Warning platesBCH Cat ID: 96017849

Installation in Bridge Deck

DRAFT

Aug 17

, 15

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:APR 2003ORIGINALLYISSUED:APR 2003

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ENGINEER OF RECORD

GENERAL TRENCHING DETAILSINSTALLATION AT REDUCED

COVER DEPTH

Notes1. The minimum burial depth may be reduced when the minimum burial depth is impractical to avoid obstructions.2. The reduced burial depth for PVC pipe shall be limited to 400 mm from the top surface of the duct bank to the finished grade.3. The duct bank shall be concrete-encased along the entire length and reduced burial depth.4. The maximum continuous length of the reduced burial depth shall not exceed 6 metres, and5. Cast iron warning plates (BC Hydro Catalogue ID 96017849) shall be installed within a finished grade at 3000 mm distance along the duct bank alignment at reduced burial depth, or 6. When installation of cast iron warning plates is impracticable, warning tape shall be replaced with warning boards (Cat ID 91002902).Cast Iron Warning Plates InstallationThe warning plates are designed primarily to be installed within a concrete sidewalk. For installation within a roadway traffic surface, its replacement should be scheduled to follow the road maintenance and resurfacing program.Installation in ConcreteThe plates shall be cast in the concrete during the sidewalk construction as follows: 1. Install a rebar loop through each hole at the bottom side of the plate;2. Tie the loops to other rebar in the concrete and secure plate in the proper position;3. Ensure that the top surface of the plate is flush with or below the roadway surface; 4. Pour the concrete, and ensure minimum concrete cover below the rebar, and5. Ensure that concrete does not cover the plate’s top surface.Installation in AsphaltThe asphalt surface of the roadway is cut for plates during pavement construction, and plates are epoxy cemented in the cut outs as follows:1. Construct roadway surface with a minimum 75 mm asphalt pavement thickness at the warning plate’s location.2. Mark the locations of warning plates at the roadway surface along the centre line of the duct bank.

a) Select locations with no deficiencies in the pavement. b) Avoid joints or cracks.c) Avoid pavement marking and line stripping.

3. Cut and grind the asphalt pavement surface at the marked locations, to a depth necessary to fully recess the warning plates in the roadway surface.

a) Cut outs shall be completely dry and free of oil and foreign materials. b) Ensure that cut is within the pavement depth.c) Abandon overcut and select other location.

3 .03

DRAFT

Aug 17

, 15

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:APR 2003ORIGINALLYISSUED:APR 2003

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GENERAL TRENCHING DETAILSINSTALLATION AT REDUCED

COVER DEPTH

4. Test the plate fitting into the cut outs, and extend cut depth if necessary. a) Allow 3 mm clearance between pavement cut and plate for epoxy to bond properly.

5. Apply epoxy grout into cut-outs, in accordance with the manufacturer’s recommendation.a) Epoxy shall comply with AASHTO M237 Type 4

6. Place warning plates into the epoxy field cut-outs a) Ensure that the top surface of the plate is flush with or below the roadway surface. b) Ensure epoxy overflows around the plate to seal the cut area. Add additional epoxy if

needed.c) Ensure epoxy does not cover the plate.d) Protect plates from traffic during the epoxy curing time.

4 .04

DRAFT

Aug 17

, 15

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:JUL 2002ORIGINALLYISSUED:JUN 1980

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ENGINEER OF RECORD

CONCRETE ENCASEMENT5” DUCT

1 .01

490 680 870

560

750

950

5" Ducts

Cov

er

Cov

er

Cov

er

150 192

146

190

Notes1. All cross-sections shown are for 125 mm (5") UD or feeder PVC duct, or rigid FRE conduit.2. All concrete-encased 5" duct banks shall be assembled using prefabricated duct spacers, cata-logue ID 96022508. For dimensional references and assembly details, refer to H2-03.02 for IPEX 5W20-2 spacers.

DRAFT

Jul 1

0, 15

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:JUL 2002ORIGINALLYISSUED:JUN 1980

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ENGINEER OF RECORD

CONCRETE ENCASEMENT5” DUCT

2 .02

Reference StandardsES54 H2-04 ReinforcingES54 H4-01 Clearances to Other UtilitiesES54 H1-02 General Trenching Details: FeedersES54 H3-01 Window Opening in Underground ChambersES54 H1-01 General Trenching Details: URD and UD InstallationES54 H2-05 Additions to Existing Duct Bank

384

146

190

192

76

Ø127

38 TYP

25TYP

TOP VIEW

FRONT VIEW SIDE VIEW

50

45

5” Duct Spacer Catalogue ID 96022508

DRAFT

Jul 1

0, 15

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:JUL 2002ORIGINALLYISSUED:JUN 1980

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M. KELVIN L. STEVANOVIC F. DENNERT

ENGINEER OF RECORD

DUCT CLEARANCES TO OTHER UTILITIES

1 .01

DRAFT

Jul 1

0, 15

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:JUL 2002ORIGINALLYISSUED:JUN 1980

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ENGINEER OF RECORD

DUCT CLEARANCES TO OTHER UTILITIES

Minimum ClearancesA minimum crossing separation is required from other utilities to provide clearance for repairs.

*Concrete encasement shall extend a minimum 3400 1500 mm on each side of crossing.Horizontal clearances shall be maintained regardless of vertical clearances. Additional separation may be required where the cables are laid in the vicinity of other power cables or metal pipes, to maintain the specified heat ratings from these nearby services.

Type of Pipe or Duct Direct-Buried BC Hydro Ducts

Concrete-Encased BC Hydro Ducts*

Clearances (mm) A B A BTelephone, cable TV or street lights 300 150 75 150Gas mains 300 300 300 300Water, oil pipelines, jet fuel lines, storm and sanitary sewers 900 300 300 300

Steam pipe 3400 3400 3400 3400

2 .02

BB

Other utility ductsOther utility ductsOther utilityducts or pipes

A

BackfillFinished grade

Typical Trench Cross SectionDirect Buried Duct

1/2

B

Warning board - extend1.2m each side from utilityduct or pipe

Warning tape board

DRAFT

Jul 1

0, 15

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.

DESIGNED RECOMMENDED ACCEPTED

ISSUED:JAN 2013REPLACES:JUL 2002ORIGINALLYISSUED:JUN 1980

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ENGINEER OF RECORD

DUCT CLEARANCES TO OTHER UTILITIES

.033

Steam PipesThe clearances shown are for steam pipes of less than 225 mm nominal diameter. For larger diame-ter steam pipes, consult the BC Hydro designer.Steam pipes shall be insulated with a minimum of 75 mm thick foam glass pipe insulation, extending a minimum of 1200 mm on each side of the crossing. Where a steam pipe crosses below the BC Hydro duct bank, the backfill material between the steam pipe and BC Hydro duct bank shall have thermal resistivity.

Railway CrossingsAt railway crossings, if the width of the duct bank exceeds 550 mm, additional strengthening may be required, as defined in CSA Standard C22.3 No. 7, Underground Systems. At railway crossings, the minimum concrete cover over ducts shall be 75 mm.

Reduced Depth of Cover The minimum cover over the duct bank may be reduced, where absolutely necessary to overcome unavoidable site obstructions, subject to the following conditions:

1. The duct bank shall be concrete encased.2. The continuous trench length at the reduced depth shall not exceed 6 metres, unless the ductsare installed in a bridge superstructure.3. The design shall be approved by the BC Hydro Distribution Engineer.

Reference DocumentCSA Standard C22.3 No. 7 "Underground Systems"

Reference StandardsES54 H1-02 General Trenching Details - FeedersES54 H1-02 General Trenching Details - URD and UD

DRAFT

Jul 1

0, 15Cast iron warning plate Cat Id 96-7849 or warning boards Cat Id 9700-0676 shall be placed

over the length of reduced duct burial. 4.

Use only for doing work with or for BC Hydro. Complete Legal Acknowledgement is at www.bchydro.com/distributionstandards.