Can a 12.47 kV grounded-wye system use a 7.2 kV winding?

Yes, when the utility specifies phase-to-neutral connection: 12.47 kV divided by √3 is about 7.2 kV. This does not describe a phase-to-phase connection. The ordered winding voltage and insulation level must match the utility diagram.

Is loop feed the same as radial feed?

No. Loop feed normally provides incoming and outgoing primary cable positions; radial feed serves an end point. Confirm the cable diagram, bushings and switching/protection arrangement rather than selecting by the cabinet photograph.

Does a pad-mounted transformer automatically have UL or utility approval?

No. Specify the required approval, utility acceptance criteria and test documents for the exact configuration. A design reference such as IEEE C57.12.38 is not a certificate for the ordered unit.

What is needed to size a replacement correctly?

Provide the existing nameplate and connection drawing, load and demand history, available fault current, cable interfaces and pad dimensions. Matching kVA alone can leave the replacement incompatible with the service or installation.

Distribution Transformers

Single-Phase Pad-Mounted Transformer

Representative configuration. The offered model, dimensions and interfaces are confirmed with the technical proposal.

Overview

Entogo supplies single-phase pad-mounted transformers for underground distribution. Specify the utility voltage, kVA, dead-front cable interface, loop or radial feed and secondary service before selecting the configuration.

Entogo supplies this project equipment through manufacturing partners. Entogo Inc. in Toronto coordinates technical selection, supply scope and order support.

Specification	Value
Construction	Single-phase, liquid-filled, compartmental pad-mounted unit
Rated capacity	kVA selected from the diversified load and utility specification
Primary voltage	State both system line-to-line and actual winding voltage
Secondary service	Specify voltage, centre tap, grounding and terminal arrangement
Frequency	60 Hz for the North-American design brief; 50 Hz requires its own design
Cable feed	Loop or radial; bushing count and elbow interface to match the utility
Protection	Fuse, surge arrester and switching scheme specified with the project
Design references	IEEE C57.12.38 / C57.12.28 and the utility specification, as applicable

Reference configurations and selection criteria are shown together. The technical offer defines the matched ratings, tests and guaranteed performance for the ordered unit.

Match the utility interface first

A grounded-wye system voltage and the voltage across a single-phase winding are different quantities. Writing only “12.47 kV” can leave the actual winding connection unclear. Provide the utility diagram and identify whether the primary connects phase-to-neutral or phase-to-phase.

A loop-feed cable arrangement also needs the correct bushing layout and operating scheme; it does not by itself promise a complete load-break switching package.

Applications

Underground distribution
Residential developments
Single-phase commercial loads

Selection & project requirements

Can a 12.47 kV grounded-wye system use a 7.2 kV winding?: Yes, when the utility specifies phase-to-neutral connection: 12.47 kV divided by √3 is about 7.2 kV. This does not describe a phase-to-phase connection. The ordered winding voltage and insulation level must match the utility diagram.
Is loop feed the same as radial feed?: No. Loop feed normally provides incoming and outgoing primary cable positions; radial feed serves an end point. Confirm the cable diagram, bushings and switching/protection arrangement rather than selecting by the cabinet photograph.
Does a pad-mounted transformer automatically have UL or utility approval?: No. Specify the required approval, utility acceptance criteria and test documents for the exact configuration. A design reference such as IEEE C57.12.38 is not a certificate for the ordered unit.
What is needed to size a replacement correctly?: Provide the existing nameplate and connection drawing, load and demand history, available fault current, cable interfaces and pad dimensions. Matching kVA alone can leave the replacement incompatible with the service or installation.

For Canadian and US projects, include the utility specification, service frequency and required approvals. State whether the order is for the transformer alone or an integrated equipment package.

Discuss your equipment requirements

Send your single-line diagram, load or process data, target market and required schedule. We will identify the configuration and documents needed for a technical quotation.

Design references

Utility distribution substation with three-phase power transformers — selecting the correct kVA rating for a North American electrical load

Power & Distribution

How to size a transformer: a practical guide to kVA selection

How to convert a real electrical load into the right transformer kVA: the calculation, the standard ANSI/IEEE rating ladder, and the margins for continuous duty, future growth, ambient and altitude that sit between calculated load and nameplate.

View

Outdoor electrical substation with distribution transformers and overhead conductors under a clear sky in Canada

Standards & Compliance

How do transformers get approved for use in Canada?

Before a transformer can be energised in Canada, the Canadian Electrical Code requires it to be "approved" — either certified by an SCC-accredited body (a CSA, cULus or cCSAus mark) or field-evaluated to CSA SPE-1000. A US-only "UL Listed" mark is not enough. Here is how the approval system actually works.

View

Pole-mounted distribution transformer governed by DOE 10 CFR 431 efficiency standards

Standards & Compliance

Transformer efficiency standards: what DOE 10 CFR 431 requires and the 2029 update

US distribution transformers must meet DOE 10 CFR 431 minimum efficiency, defined at 35 percent load for dry-type units and 50 percent for liquid-immersed. A 2024 final rule raises those floors for units built on or after April 23, 2029, and here is how the rules work and what to specify.

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Related equipment

Representative outline drawing of an Entogo three-phase dead-front pad-mounted transformer — front and side elevations, not a photograph

Products

Three-Phase Pad-Mounted Distribution Transformer

Three-phase pad-mounted distribution transformer for North American utility, commercial and industrial service — 75–2500 kVA, 12.47–34.5 kV class primary to 480Y/277 or 208Y/120 secondary, dead-front loop/radial-feed, NEMA 3R. Designed to IEEE C57.12.34 and DOE 10 CFR 431; UL/CSA certifiable.

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Products

High-Voltage Power Transformer

Entogo supplies high-voltage power transformers for substations and industrial networks. The design brief covers MVA, voltage ratio, insulation coordination, impedance, tap regulation, cooling and transport limits.

View

Entogo inverter-duty solar and storage step-up unit substation skid

Products

Solar / Storage Skid — Inverter-Duty Step-Up Unit Substation

An inverter-duty step-up unit substation (solar/storage skid) integrating a liquid-filled step-up transformer, MV switching and inverter interface — stepping inverter output up to 34.5 kV for PV and battery-storage interconnection, 60 Hz. Designed to IEEE C57.12.34, C57.159 and C37.121; UL/CSA certifiable.

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Products

Electrical Isolation Transformer

Entogo supplies electrical isolation transformers with separate primary and secondary windings. Select voltage ratio, kVA, shielding, grounding and enclosure for the load; isolation duty and dry-type construction are distinct requirements.

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Match the utility interface first

Discuss your equipment requirements

How to size a transformer: a practical guide to kVA selection

How do transformers get approved for use in Canada?

Transformer efficiency standards: what DOE 10 CFR 431 requires and the 2029 update

Three-Phase Pad-Mounted Distribution Transformer

High-Voltage Power Transformer

Solar / Storage Skid — Inverter-Duty Step-Up Unit Substation

Electrical Isolation Transformer

Customer support