3.0 urd design guidelines figure 3.1 - looped primary urd

Page: 3-1Revision: 2011-11-01

SPECIFICATIONS FOR NEW UNDERGROUND RESIDENTIAL DISTRIBUTION SYSTEMS________________________________________________________________________________________________

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This document is the property of ATCO Electric and is for authorized use only.

3.0 URD DESIGN GUIDELINES

3.1 Overview of ATCO Electric’s URD System Design

ATCO Electric’s design for distribution power supply to URD areas is a primarylooped supply system. This is generically illustrated in Figure 3.1. The supplyvoltage is 25 kV.

Figure 3.1 - Looped Primary URD System

The power supply to all single lot underground residential services is throughfront lot service. Single phase transformers are connected to secondarypedestals, which in turn provide the connection to the residential service. Thesecondary supply design provides an interconnection or “looping” of thesecondary conductors between the service pedestals. This allows for moreefficient and responsive restoration of service to customers in the event of atransformer failure.

Figure 3.2 illustrates a typical front lot service with the subdivision primary andsecondary pedestal cable and secondary service cable connections. Thesupply is at 120/240 volts.



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Figure 3.2A - Single Family Dwelling Lot Service with Looped SecondaryCables

With the exception of commercial customers fed from a separate transformer,all secondary services are served from a secondary pedestal box connected toa transformer.



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Figure 3.2B – Multiple Family Dwelling Lot Service Bare Land Development



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3.2 URD Design

This section outlines the responsibilities and standards for design of anunderground electrical distribution development within a neighborhood or majorsubdivision. It is intended to assist the Developer and/or its agent(s) inpreliminary design discussions with ATCO Electric’s EngineeringRepresentative.

3.2.1 Design Responsibilities

ATCO Electric is responsible for planning and designing the express andsource primary feeders which supply an URD. In addition, ATCO Electric isresponsible for the planning, design, construction, installation andtermination of three phase switch cubicle facilities.

ATCO Electric’s Engineering Representative will at the request of theDeveloper and/or its agent(s), provide:

a) information on the switch cubicle requirements (dimensions, scheduleand locations); and

b) normally open/closed points at transformers for the specification oflightning arrestor locations.

Figure 3.3 is a schematic representation of the facilities ATCO Electricand the Developer are each responsible to provide and install. Facilitiesshown in blue are ATCO Electric’s responsibility, and facilities shown inblack are the responsibility of the Developer and/or its agent(s).



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Figure 3.3 - URD System Design Responsibilities



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3.2.2 Design Standards

All underground electrical distribution facilities must be designed inaccordance with the Alberta Electrical Utility Code (AEUC) and anyamendments thereto under the Alberta Safety Codes Act; and, whereapplicable, the Canadian Electrical Code (CEC) – Part III.

The minimum acceptable design standards to be met by the Developerand/or its agent(s) will be the higher of the ATCO Electric standardsestablished in these specifications or that of the governing authority.

Adherence to the planning and design standards ensures ATCO Electric isable to maintain adequate service levels. Safety (grounding), voltagequality, reliability and equipment life are key factors.

3.2.2.1 Ultimate Design

The design proposed by the Developer and/or its agent(s) must considerfuture stage development (i.e., the "ultimate" design).

Ultimately, all subdivision primary cables and transformers must have alooped source or an alternate source of supply; that is, a minimum of twoprimary feed-in points (refer to Figure 3.1). The commissioning or use ofthe alternate feed in normal system operations or in emergencysituations must require only the switching of normally open or closedswitches at the switch cubicles supplying a subdivision area. Allsecondary services are to be fed directly from pedestals and looped(refer to Figure 3.3).

Supply to three phase transformers (i.e., commercial feeders) mustnot be used or integrated from power cables designed for supplyingsingle phase residential services. Where three phase loads andservices are required, the three phase system must be planned anddesigned so that all three phase transformers are isolated from the



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single phase residential feeders by the use of switch cubicles and/orseparate feeders. Figure 3.3 illustrates this concept.

3.2.2.2 Initial Design

Subdivision development may proceed in several phases and timeframes. As such, temporary (in this context, for less than 1 year)arrangements for primary power cable and equipment are required;that is, provision for temporary looping and/or extension to futurephases. The Developer and/or its agent(s) are responsible tocoordinate these arrangements with ATCO Electric’s EngineeringRepresentative prior to the commencement of any detailedengineering or construction of the underground distribution system.

ATCO Electric’s Engineering Representative will make the finaldecisions regarding the system configuration. Options to beconsidered include:

a) creation of temporary phase changes/loops by parking primarypower cables in the padmount transformers nearest the stagelimits;

b) cap and coil 30m of primary power cables at the end of the stagelimits;

c) installation of ducts to the development boundary; and

d) placement of padmount transformers at the developmentboundaries.

Note: ATCO Electric will not accept splices in the design ofunderground distribution facilities for an URD (see Section 5.3.1).Each unnecessary splice introduces another element which can failand degrade the performance of the system.



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3.2.2.3 Street Light Design

The location of street light facilities is a critical consideration in thedesign of an URD subdivision, to ensure required lighting levels areachieved in all areas. Space is limited within subdivision URWsand/or easements, and the location of street lights will impact theavailable locations for padmount switching facilities and transformers.

Further, it is critical to ensure that no more than one distributionfacility is installed in close proximity to a single lot (e.g.,transformer/pedestal and street light). These facilities should bereasonably and equitably located on lots throughout the subdivisionarea.

3.3 Performance Requirements

3.3.1 Grounding

The proper design and installation of the grounding system isfundamental to the safe operation of an URD system. Protectivesystems (i.e., fuses, circuit breakers) must be in place and operate torapidly disconnect a faulted piece of equipment (e.g., a cable,transformer, etc.). In addition, the grounding system must limit the rise instep-and-touch voltage to a safe level for persons in proximity to theequipment when it faults. The Consulting Engineer is responsible toensure all the requirements of the AEUC and Part III of the CanadianElectrical Code are met for the grounding of all equipment.

3.3.2 Short Circuit Ratings

The Consulting Engineer is responsible to ensure all equipment to beincluded within an URD has a sufficient short circuit rating. TheDeveloper and/or its agent(s) are responsible to contact and obtain therequired information from ATCO Electric’s Engineering Representative.



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3.3.3 Voltage Drop

The nominal system voltage and voltage limits at the service entranceare as specified in the Canadian Electrical Association (CEA) ReferenceStandard for Canadian Practice – Preferred Voltage Levels For AC Systems0 - 50 000 Volts, and CSA Standard CAN 3 – C235 - B3, Table 3.

For circuits up to 1,000 volts, the recommended voltage variation limits atthe service entrance are summarized in Table 3.1.

Table 3.1 - Limits of Operating Voltage

EXTREME OPERATING CONDITIONS

NORMALOPERATINGCONDITIONS

SINGLE PHASE120/240 106/212 110/220 125/250 127/254

240 212 220 250 254THREE PHASE 4

CONDUCTOR120/208Y 110/190 112/194 125/216 127/220347/600Y 306/530 318/550 360/625 367/635

THREE PHASECONDUCTOR

240 212 220 250 254600 530 550 625 635

ATCO Electric will try to ensure that the minimum voltage under normaloperating conditions, at the primary source points, is not less than 13.6kV line-to-neutral. This is equivalent to a maximum 12.8 V drop on a 240V base. The maximum voltage drop for the subdivision primary andsecondary to the customer service entry point for any customer is 7.2 V,or 3.0% on a 240 V base.



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For design purposes, the load for residential services and street lightsshould be modeled as a constant kVA load at a 90% power factor. Thisis a conservative design which, in a contingency situation, should allowcustomers to be supplied with a voltage within emergency operatinglimits.

The voltage drop at the customer’s service entry point on the loss of asingle phase padmount transformer is to be calculated with the loadmodeled at 50% constant kVA and 50% constant impedance. Thisreflects a mix of service motor, lighting and resistive loads.

See Table 3.2 for the cable impedances to be utilized for the calculationof voltage drop for subdivision single phase primary cables. As the returnpath for the current is through the neutral conductor and the ground (thecables are grounded at both ends), associated effects must beconsidered when calculating the effective cable impedance.

Table 3.2 -Loop Impedances of Single Phase Concentric Neutral Aluminum Cable1

Conductor

Size

Concentric Neutral(size and number

of strands of wire )R X

2 10 #14 1.5114 0.6091

1 13 #14 1.2900 0.4976

1/0 16 #14 1.0962 0.4130

4/0 13 #10 0.6333 0.2011

300 MCM 18 #102 0.47282 0.14432

Reference: Short, T.A., Electric Power Distribution Handbook, CRC Press, 2004, p. 21,Table 3.1.3.

1. Impedances are in Ohms/km. Conductor temperature = 90 C, Neutral Temperature =80 C, 15-kV class 220-mil insulation, soil resistivity = 100 Ohms/metre.

2. Values interpolated between 250 MCM and 350 MCM in the referenced table.



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The cable impedances for secondary USEB90 cables (where the neutralconductor surrounds both phase conductors) are not readily available inreference books. The impedances provided in Table 3.3 for thesecondary conductors typically utilized in these specifications wereobtained from the Engineering Design Group of the Alcan CableCompany.

Table 3.3 - Loop Impedances of 2/c Single Phase USEB90Concentric Neutral Aluminum Secondary Cables1

Conductor

Size

Concentric Neutral(size and numberof strands of wire )

R X

2 16 #16 1.090 0.132

1 13 #14 0.871 0.129

1/0 16 #14 0.690 0.123

4/0 32 #14 0.345 0.105

300 MCM 32 #12 0.244 0.098

Reference: Alcan Cable Company, Engineering Design Group.

1. Impedances are in Ohms/km. Conductor temperature = 90 C, Neutral Temperature =80 C, 15-kV class 220-mil insulation, soil resistivity = 100 Ohms/metre.

Detailed voltage drop calculations must be included in the informationpackage provided to ATCO Electric for review (i.e., calculationscompleted on spreadsheets or by power analysis software such as, butnot limited to ETAP or CYME). See Appendix C, Document C.1.6, forsample calculations completed on a spreadsheet. Note: The ConsultingEngineer should utilize the impedance characteristics of the cable at therated operating temperature to calculate the voltage drop.

Refer back to Table 3.1. For the design to be accepted:

a) the voltage must be maintained within the limits for Normal OperatingConditions at the customer meter;



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b) on the loss of a single phase padmount transformer or subdivisionprimary feeder, the voltage must be maintained within the limitsfor Extreme Operating Conditions (i.e., emergency operating limits);and

c) on the loss of a transformer, the site with the lowest voltage (i.e., thegreatest voltage drop) fed off that transformer must be maintainedwithin emergency operating limits.

3.3.4 Transformer Loading

The number of customers who can be satisfactorily supplied from atransformer (in terms of the voltage quality and thermal limits of theequipment) depends on the diversity of the loads of the customers.Each customer will have different consumption patterns according totheir routines, house comfort levels, and the efficiency of their electricalequipment and so on. The diversity factors provided in Table 3.4 arerecommended for the design of single phase subdivision primary feedersand transformers.

Table 3.4 - Diversity Factors

No. ofLots

CoincidenceFactor

DiversityFactor

3 0.85 1.184 0.77 1.305 0.69 1.456 0.67 1.507 0.64 1.568 0.61 1.639 0.59 1.7010 0.56 1.78

Reference: Willis, H. Lee, Power Distribution PlanningReference Book, CRC Press, 2004, p. 812, Figure 22.10.



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Tables 3.5, 3.6 and 3.7 identify the maximum number of 100 amp, 200amp or a combination of 100/200 amp customers (services) that cannormally be supplied from ATCO Electric’s standard single phase 14.4kV– 120/240V (nominal) rated primary and secondary loop-feed transformersto maintain the voltage within the limits identified in Section 3.3.3.

These tables are to be used as guidelines only. The number ofservices that can be supplied may be limited by size restrictions of thesecondary compartments and/or the allowable secondary power cablevoltage drop. ALL designs and calculations submitted must meetvoltage and loading requirements.

Table 3.5 - Maximum Number of 100 AServices Supplied by Padmount Transformers

Transformer Size 100 A Services50kVA 1675kVA 24

100kVA 31

Table 3.6 - Maximum Number of 200 AServices Supplied by Padmount Transformers

Transformer Size 200 A Services50kVA 875kVA 12

100kVA 15

Table 3.7 - Maximum Number of a Combination of 100Aand 200 A Services Supplied by Padmount Transformers

Transformer Size 100 A Services 200 A Services50kVA 12 275kVA 16 4

100kVA 22 8



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3.3.5 Cable Ampacity

The maximum current (at a nominal 25 kV) that each conductor isallowed to carry is identified in Tables 3.8 and 3.9.

Table 3.8 - Ampacities of Direct Buried Cable

Cable Size Maximum Amps1

#1 AL 195350MCM AL 428500MCM AL 521

1. Assumes cables direct buried in trench with a minimum separation of one full cablediameter from another phase cable, phase max temperature 90 C, and ambient earthtemperature 20 C.

Table 3.9 - Ampacities of One Cable in One Duct

Cable Size Maximum Amps1

#1 AL 169350MCM AL 375500MCM AL 465

1. Assumes phase max temperature 90 C.

These ratings are in accordance with ATCO Electric’s design standards.

In developing the subdivision design, care must be taken to ensure the

cables are not undersized for existing and future phase developments.

3.3.6 Reliability Considerations

The secondary design is such that on the failure of a transformer,

voltage is quickly restored to within emergency operating limits so the

customer’s essential equipment can continue to operate pending a full

repair. A secondary loop system allows for quicker restoration of service

than a radial secondary system following a transformer fault.

Primary and secondary splices are not accepted or allowed in URD

system design, in order to achieve an adequate reliability level (see

Section 5.3.1).



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3.4 Cable Trench Alignments/Depths

Standard alignments for underground power and other joint-use facilities aregenerally defined by the Municipal Authority It is the responsibility of the Developerand/or its agent(s) to obtain the most current version from the Municipal Authority.,at a minimum the alignment must conform with the drawings in Appendix D,specifically Drawings D.2.1, D.2.2, D.2.3, D.7.1A, D.7.1B, D.7.2, D.7.3, D.7.4, andD.7.5.

3.4.1 Express Feeders

Any express feeders identified by ATCO at the Preliminary Design stage

will be designed by ATCO Electric. Information will be provided to the

Developer and/or it agent(s) at the design review. The express feeder

will be installed in 102mm or 150mm ducts (if required, and dependent

on cable size) in a separate/common trench located in a URW and/or an

easement on a boulevard. The centre line of trench alignment will be

determined by the ATCO Electric Engineering Representative.

While ATCO Electric will design any express feeders within a

subdivision, the Developer and/or its agent(s) may be required to provide

and install the civil works and install ducts and omni balls wherever road

crossings are necessary (see Section 2.2 and Table 2.1, Note 1). The

road crossings will be outlined by ATCO Electric’s Engineering

Representative.

3.4.2 Subdivision Primary Feeders

After submission of the development plans to ATCO Electric but prior to

starting the design, the Developer and/or its agent(s) are responsible to

obtain the distribution system planning requirements, which includes the

source points, from the ATCO Electric Engineering Representative.



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3.4.2.1 Four Party Trenching

Four party trenching involves the installation of subdivision primarydistribution cables, secondary cables, street light cables,communications cable, cable TV and gas pipes in one (1) commontrench, as per the typical front lot alignments and standard trench detailsshown in Appendix D, Drawing D.1.7.

Any deviations to the standard vertical or horizontal alignments must

be accepted in advance by ATCO Electric’s Engineering

Representative. The Developer must also obtain the approval of the

other shallow utilities.

3.4.2.2 Three Party Trenching

Three party trenching involves the installation of subdivision primarydistribution cables, secondary cables, street light cables,communications cable and cable TV in one (1) common trench, as perthe typical front lot alignments and standard trench details shown inAppendix D, Drawings D.1.5 and D.1.6.

Any deviations to the standard vertical or horizontal alignments must

be accepted in advance by ATCO Electric’s Engineering

Representative. The Developer must also obtain the approval of the

other shallow utilities.

3.4.2.3 Two Party Trenching

Two party trenching involves the installation of subdivision primarydistribution cables, secondary cables, street light cables andcommunications cable or cable TV in one (1) common trench, as per thetypical front lot alignments and standard trench details shown inAppendix D, Drawings D.1.5 and D.1.6.



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Any deviations to the standard vertical or horizontal alignments mustbe accepted in advance by ATCO Electric’s EngineeringRepresentative. The Developer must also obtain the approval of theother shallow utilities.

3.4.2.4 One Party Trenching

Single party trenching involves the installation of primary distributioncables, secondary cables and street light cables in one (1) commontrench, as per the typical front lot alignments and standard trenchdetails shown in Appendix D, Drawings D.1.1, D.1.2A and D.1.2B.

Any deviations to the standard vertical or horizontal alignments mustbe accepted in advance by ATCO Electric’s EngineeringRepresentative.

3.4.2.5 Service Entry Trench to Lot

For Single Family Dwelling service box and stake are to be installed0.5m from the easement and 1.5m from the lot line and NOT under adriveway. See Appendix D, Drawings D.3.1A, D.3.2, D.5.1 andD.5.2.

For Multiple Family Dwelling service box is typically not required asthe building foundation is in place prior to construction. Servicetrench shall be minimum 1.5m from the building. See Appendix D,drawings D.3.1B

3.5 Primary and Secondary Cables

3.5.1 Primary Cables

The following cables are to be utilized for subdivision primary service:



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1/C – #1 AWG TRXLPE compact aluminum strand 100% Cu concentricneutral1/C – 350 MCM TRXLPE compact aluminum strand 100% Cu concentricneutral

For detailed primary cable specifications, see Appendix E, Document E.1and Specifications 11040 and 9666.

3.5.2 Secondary and Service Drop Cables

The following cables are to be utilized for secondary service:

2/C - #2 600V aluminum conductor jacketed type USEB90 reducedCu concentric neutral2/C – 4/0 600V aluminum conductor jacketed type USEB90 reducedCu concentric neutral2/C – 300 MCM 600V aluminum conductor type USEB90 100% Cuconcentric neutral

For detailed secondary cable specifications, see Appendix E, Document E.2and Specifications 10441 and 10451.

For Single Family Dwelling services, the design for the service drop mustshow a minimum length of 30 metres of secondary cable from the edgeof a service box entrance to the customer’s meter. The voltage drop atthe end of the service drop cable must be within the limits identified inSection 3.3.3.

For Multiple Family Dwelling Services within Bare Land ResidentialDevelopment the service conductor shall be 2/C - 300 MCM aluminiumconductors. Developers shall be responsible for trench and installation ofservice conductors up the multi-meter junction box. See Appendix D,drawing D.3.1B and D.2.5.



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3.6 Switch Cubicles

ATCO Electric's Engineering Representative will provide the Developerand/or its agent(s) with information related to the switch cubiclesrequired to supply a subdivision area (i.e., preliminary location, schedule,size and configuration). The Developer and/or its agent(s) areresponsible to propose a final location for the approval of ATCOElectric’s Engineering Representative.

The switch cubicle must be located a minimum distance of 3.0m from thecurb, and a 6.0m x 6.0m easement is required. If necessary, theDeveloper and/or its agent(s) will provide ATCO Electric with theeasement (see Section 4.2.2).Note: The distance from the curb must take into consideration the sizeand location of the base ground grid, which extends 0.5m to 1.0mbeyond the boundaries of a switch cubicle base (see Appendix D,Drawing D.4.5).

3.7 Padmount Transformers and Secondary Pedestals

3.7.1 Installation

For the purposes of these specifications, padmount transformers will besingle-phase, 14.4kV – 120/240V (nominal) rated primary and secondary,loop-feed transformers, and three-phase, 25kV – 120/208V or 347/600V(nominal) rated primary and secondary, loop-feed transformers.

For Single Family Dwelling, no services will be fed directly from thetransformer; a secondary pedestal is always required. A street light maybe fed from either a transformer or a pedestal.

For Multiple Family Dwelling, services will be fed directly from thetransformer; a secondary pedestal is not required. A Street light maybefed from either a transformer or a pedestal.



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Padmount transformers are to be installed as follows:

a) The transformers must be mounted on precast bases located atintersecting lot lines, and coordinated with other facilities located onthe street so as not to encumber both lot lines of any residentialfamily zoned lot.

b) The precast base, where possible, should be located 0.5m fromeasement on a boulevard, or 0.5m from the edge of the trench, butonly if the required ground grid will not be under existing or proposedsidewalks, curbs, roadways, and other known structures or on privateproperty. lf such a conflict exists; the precast base must be shifted toallow for the ground grid installation. The Developer and/or itsagent(s) are responsible to provide the required alignments.

c) c) If the Consulting Engineer wishes to install a transformer on theopposite property line of a street light, the Developer and/or itsagent(s) must include an approved driveway plan for all lots withinthe subdivision with the first submission of the detailed engineeringplans. In addition, the Developer must provide a letter acceptingresponsibility for all costs of relocating the equipment due to changesin the location of driveways. This option is available only if all otherconditions regarding transformer location are met.

d) Transformer bases must NOT be:

i. offset into pie-shape properties with frontages of less than 15.0m;ii. set closer to a corner cut than 6.0m;iii. located with less than a 1.0m side clearance to all other

facilities, and less than a 2.0m clearance to bus stops and curbcuts;

iv. set in a sidewalk; orv. placed on the driveway side of a lot.

e) Furthermore:



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i. No pedestal or street light should be placed on the driveway sideof a lot. (If this cannot be avoided, ATCO Electric’s CSR shouldbe consulted).

ii. The transformer is to be positioned so its access lid/door facesthe roadway.

iii. The street light is to be positioned as follows: Single Davit the access door is to be positioned so that the

employee is facing oncoming traffic when working in the lightstandard where possible;

Double Davit installed on an island the door is to be installedparallel to the road so that the employee has visibility ofapproaching traffic from either direction when working in thestandard.

iv. The pedestal is to be positioned as follows: When the pedestal is parallel to the road the pedestal door

faces the house including pedestal/transformercombinations and street light/pedestal combinations;

When the pedestal is placed perpendicular to the roadsurface the door shall be positioned so that when accessingthe pedestal the worker is facing oncoming traffic. .

See Appendix D, Drawings D.3.1, D.3.1B, D.3.2, D.4.15 D.7.1A,D.7.1B, D.7.2, D.7.4, D.7.6C, D.7.7, D.7.8 and D.7.9 for transformerand pedestal alignment, orientation and clearance details.

3.7.2 Equipment Identification

The circuit and equipment identification and tagging requirements on theengineering drawings must be accurate and match the identification andtags on the cables and equipment installed. Appendix D, drawings D.5.6,D.5.7, D.5.8, D.5.9, D.5.10 and D.5.11.

3.7.3 Grounding



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The Developer and/or its agent(s) are responsible, as part of the overallinstallation of the URD system, to complete the design, installation andinterconnection of ground facilities at each padmount transformer location asper Appendix D, Drawings D.4.5 and D.4.6. The grounding materials mustmeet the requirements of Appendix E.5.

All conductive above-ground facilities (e.g., metal guard posts or bollards,

stand-alone cable TV and communication pedestals, metering pedestals,

etc.) within 3.0m of a transformer pedestal must be tied into the pedestal’s

ground grid.

3.8 Primary Fusing

ATCO Electric will complete the primary fuse coordination at the switch cubicle andsupply the required on-site fuse units.

3.9 Street Lighting

Typically, the Municipal Authority will dictate the roadway lighting requirements,including lighting levels, lighting types, festoon electric plugs, locations andownership or responsibility for the facilities within the development area. Refer tothe Municipal Authority’s most recent guidelines. Festoon electric plugs must beinstalled on all light standards on roadways with four (4) or more lanes.

Required illumination levels for a roadway are determined by the classification anduse of the roadway. The Developer and/or its agent(s), unless directed otherwiseby the governing authority, will utilize the American National Standard Practice forRoadway Lighting, publication RP-8 of the Illuminating Engineering Society of NorthAmerica (IESNA), as the minimum standard for the design of safe and efficientroadway lighting in urban residential and commercial areas.

The Developer and/or its agent(s) must check the roadway classifications with theappropriate roadway authority before proceeding with any detailed engineering orconstruction of street lights and the underground electrical distribution system.



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Street lighting design calculations and documentation must be submitted for ATCOElectric’s acceptance; the minimum requirements are described in Section 4.0. Asample of inputs and calculations utilizing a computer program is provided inAppendix C, Document C.1.7.

All designs must be based on a uniform tilt of zero degrees (0o). For single lot, Allstreet light circuits must be fed from secondary pedestals, in accordance with therequirements of Section 3.5.2. The individual street light davits are to be controlledby a photoelectric cell mounted on each davit.

In residential areas, street light standards should be placed on lot lines, wherepractical. In subdivisions with curved roads and irregular lot sizes, another locationmay have to be determined to meet lighting requirements. When installingpedestals, it is recommended to pair pedestals with street lights to minimize facilitylocations and the visual impact to lot owners.

See Appendix D, Drawings D.7.1A, D.7.1B and D.7.2 for street light alignmentdetails.

3.10 Landscaping Adjacent to Underground Electrical Equipment

Before commencing the design of an URD system, the Developer and/or itsagent(s) must confirm landscaping plans with the Municipal Authority, including allvegetation for the area. See Appendix D, Drawings D.7.6A, D.7.6B, and D.7.6C fordetails.

3.0 urd design guidelines figure 3.1 - looped primary urd

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