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​2.0 Padmount Transformer

A ground-mounted transformer located on private property. Typical installations include medium to large commercial applications, large houses, and multi-family sites.

Table 1A

​Commercial Service Limits Residential Service Limits​

120/240 V, 1 Ph, 3 W – 600 A
240 V, 3 Ph, 3 W – N/A
120/208 V, 3 Ph, 4 W – 2,800 A
120/208 V, 2 Ph, 3 W – N/A
277/480 V, 3 Ph, 4 W – 2,200 A (Temporary Service)
347/600 V, 3 Ph, 4 W – 2,400 A

120/240 V, 1 Ph, 3 W – 600 A
120/208 V, 2 Ph, 3 W – N/A

Services larger than 100 A by special permission only.

 

​Customer's Responsibilities

  • Complete civil work on private property. This typically includes all trenching, ducting, pull boxes, concrete bases for any padmount equipment, grounding, and guardrails.
  • Supply and install secondary cable.
  • Install Current Transformers and Potential Transformers.
  • Supply the primary cable on multi-family sites.

NOTE: The customer owns and maintains all transformer bases, switching cubicle bases, ground grids, primary ducts, and all secondary works on private property. Customer owns and maintains primary cable in MFU sites.

​EDTI's Responsibilities

  • Complete all work on public property.
  • Supply primary cable, except for multi-family sites, where the customer supplies the primary cable.
  • Supply, install, and terminate all padmount equipment.
  • Supply Current Transformers and Potential Transformers
  • Supply and install revenue metering equipment.

NOTE: EDTI owns and maintains all transformers, switching cubicles, primary cable (except for multi-family sites), and revenue metering equipment.

Service Connection Point (Service Entry Point)

Property line.

Point of Service Termination (Electrical Connection Point)

Property line for multi-family sites, transformer for all other installations.

2.1 General introduction

  • A padmount transformer service refers to a ground-mounted transformer located on private property.
  • Typical installations include medium to large commercial applications, large houses, and multi-family sites.
  • Please see Table 1 below for a summary of your responsibilities as the customer and EDTI's responsibilities.
  • If you decide that you require a padmount transformer service, please complete the Commercial or Single-Family Residential Application Form and email it to ces@epcor.com.
  • See the Additional Information in Section 9 to learn about such topics as temporary power, splicing, operations, equipment relocation, and pre-inspection checklists.
  • The information is divided into sections to make it easier for you to find what you need, but EDTI strongly suggests that you read all the information before starting.
  • If there are any differences between this information and EDTI's Terms and Conditions, the Terms and Conditions will govern. In addition, regulations contained in the Canadian Electrical Code, Alberta Electrical Utility Code, Alberta Safety Codes Act, and Alberta Occupational Health and Safety Act must be followed.
  • For the safety of public, City of Edmonton bylaws require residents or property owners to always keep power assets clear of trees, shrubs, rocks, debris and other items.
  • The customer must comply with the clearances set out in the Canadian Electrical code for required vertical clearances when crossing to other utilities.

Table 1

​Customer's Responsibilities

  • Complete civil work on private property. This typically includes all trenching, ducting, pull boxes, concrete bases for any padmount equipment, grounding, and guardrails.
  • Supply and install secondary cable.
  • Install Current Transformers and Potential Transformers.
  • Supply the primary cable on multi-family sites.

NOTE: The customer owns and maintains all transformer bases, switching cubicle bases, ground grids, primary ducts, and all secondary works on private property. Customer owns and maintains primary cable in MFU sites.

​EDTI's Responsibilities

  • Complete all work on public property.
  • Supply primary cable, except for multi-family sites, where the customer supplies the primary cable.
  • Supply, install, and terminate all padmount equipment.
  • Supply Current Transformers and Potential Transformers
  • Supply and install revenue metering equipment.

NOTE: EDTI owns and maintains all transformers, switching cubicles, primary cable (except for multi-family sites), and revenue metering equipment.

Service Connection Point (Service Entry Point)

Property line.

Point of Service Termination (Electrical Connection Point)

Property line for multi-family sites, transformer for all other installations.

2.2 Standard supply voltages

  • To see the standard voltages available from EDTI for this type of service, please see the Select the Service Type That Works for You (1.4) section.
  • Maximum service limits apply to services within our 15 kV and 25 kV service areas. For any new or increased services in the 5 kV distribution area, contact us for limits. Refer to Drawing 29 for the primary voltage in your area, and contact us for confirmation.
  • 240 V, 3-phase, 3-wire services are not available from padmount transformers.
  • 1-phase equipment cannot be connected to 240 V, 3-phase, 3-wire services.
  • Two or more services of the same voltage will not be supplied to the same premises. An example would be a 120/240 V, 1-phase, 3-wire service and a 120/208 V, 3-phase, 4-wire service.

2.3 Permits and inspections

As a customer, you or your contractors are responsible for:

  • Obtaining all permits, certificates, licences, inspections, reports, and other authorizations necessary for installing and operating the service connection. EDTI is not required to start or continue operation of a service connection unless the customer has complied with the licensing requirements of EDTI and all other authorities.
  • Submitting an electronic copy of the electrical wiring permit, civil electrical inspection (if required), and final electrical inspection report to EDTI Customer Engineering Services.
  • Ensuring that an Electrical Safety Codes Officer inspects all internal wiring before it's concealed. All transformer and switching cubicles, ground grids, underground wiring, and ducts must be inspected before the trench is backfilled. Contact the City of Edmonton to arrange for inspections. A service connection will not be energized unless you have received  inspection approval.
  • Completing utility searches on private property and notifying Alberta One-Call before any work is done.

2.4 Service connection agreement

  • EDTI requires the customer to sign the Customer Acceptance portion of the estimate letter as confirmation of intent to proceed with construction. This is required before EDTI finalizes the design and issues work orders.
  • EDTI may require the customer to sign a Construction Commitment Agreement, Electric Service Agreement, and/or Interconnection Operating and Maintenance Agreement.
  • The customer may be required to make a capital contribution toward the cost of materials and equipment installed on City of Edmonton property or the customer's property.

2.5 Drawing requirements

  • EDTI Customer Engineering Services reserves the right of final approval for the location of facilities before EDTI will grant construction approval.
  • New connection construction cannot start until EDTI has approved all drawings.
  • A customer requesting a padmount transformer service must submit a copy of the following:
  • Drawings must be in electronic format and follow accepted drafting standards as indicated in this guide.
  • Drawings will become part of EDTI Customer Engineering Services' record system and must be submitted in PDF and AutoCAD or MicroStation format.
  • The following information must be included on these plans:
    • All legal property lines
    • Streets, avenues, and any other public thoroughfare abutting the property
    • Locations of planned and existing buildings
    • Size and location of primary and secondary conductors on the line (source) side of the meter
    • Size and location of pull boxes and pedestals
    • Direction of door openings for padmount transformers and cubicles
    • Location and size of the main distribution panel within the building, including voltage, amperage, phase, wire size, temperature rating (i.e., 75 or 90 degree), and type
    • A detailed drawing of the electrical room layout
    • Easements and rights-of-way located on the customer's property
    • Location and description of all other utilities crossing or located within 3.0 m of proposed power facilities and conductors
    • Drawings at a scale that will maintain the readability of multiple conductors, which can be submitted as multiple sheets if necessary to meet the readability criteria as long as each sheet is self-contained
    • Electrical permit number and legal address
    • Title, block, border, scale, and legend

Please note that all equipment and conductor locations on the drawing are to be dimensioned from the building and property lines and given real-world coordinates. Curb lines may also be included.

EDTI Customer Engineering Services will review and accept drawings and the scope of work.

2.6 Horizontal clearance to other utilities

The following horizontal clearances to other utilities from underground service lines and equipment, including padmount transformers, switching cubicles, guardrails, and ground grids, must be maintained:

Commercial Installations

  • Primary and Secondary Conductors

    • 2.0 metres to all valves, hydrants, catch basins, manholes, vaults, sanitary and storm sewer lines, septic tanks, fields, and Minnesota mounds. The primary cable cannot cross through septic fields and Minnesota mounds.
    • 1.8 m to all water lines and cc valves.
    • 1.0 m to all gas lines.

Residential Installations (Single-Family and Multi-Family Units)

  • Primary Conductors

    • 2.0 metres to all valves, hydrants, catch basins, manholes, vaults, sanitary and storm sewer lines, septic tanks, fields, and Minnesota mounds. The primary cable cannot cross through septic fields and Minnesota mounds.
    • 1.8 m to all water lines and cc valves.
    • 1.0 m to all gas lines.
  • Secondary Conductors

    • 2.0 metres to hydrants, catch basins, manholes, septic tanks, fields, and Minnesota Mounds. Secondary cables cannot cross through septic fields or Minnesota Mounds.
    • 2.0 m to sanitary and storm sewer lines.
    • 1.0 m to water lines and cc valves.
    • 1.0 m to gas lines when in separate trenches. On residential properties where a 4-party joint-use trench is used, there must be a minimum of 0.3 m of separation, and a marker tape must be installed 0.5 m above the service cable.