--- title: "Three-Dimensional Wound-Core Transformer (Low-Loss) | Entogo" description: "A three-dimensional (triangular) wound-core distribution transformer with a closed, symmetric core for lower no-load loss, balanced flux, low noise and…" url: https://entogo.ca/products/wound-core-distribution-transformer/ lang: en type: website image: https://entogo.ca/_astro/Entogo-Stereoscopic-Triangular-Transformer.ChH9EFSn.png alternates: en: https://entogo.ca/products/wound-core-distribution-transformer/ fr-CA: https://entogo.ca/fr/products/wound-core-distribution-transformer/ es: https://entogo.ca/es/products/wound-core-distribution-transformer/ ar: https://entogo.ca/ar/products/wound-core-distribution-transformer/ site: https://entogo.ca/ llms: https://entogo.ca/llms.txt --- Home › Products › Transformers & Substations › Three-Dimensional Wound-Core Transformer (Low-Loss) Transformers & Substations # Three-Dimensional Wound-Core Transformer (Low-Loss) Triangular wound core · oil or dry Configure & quote ## Customize your Three-Dimensional Wound-Core Transformer (Low-Loss) and get a quote. [Configure & get a quote](https://entogo.ca/products/transformer-quote/?from=Three-Dimensional%20Wound-Core%20Transformer%20(Low-Loss)) ![Entogo three-dimensional triangular wound-core low-loss distribution transformer](https://entogo.ca/_astro/Entogo-Stereoscopic-Triangular-Transformer.ChH9EFSn_Z1ffw8C.webp) Overview A three-dimensional (triangular) wound-core distribution transformer with a closed, symmetric core for lower no-load loss, balanced flux, low noise and high short-circuit withstand — oil-filled or dry-type, 15/25/35 kV class, 60 Hz. Designed to IEEE C57/UL and DOE 10 CFR 431; UL/CSA certifiable. Entogo designs and builds the Three-Dimensional Wound-Core Transformer (Low-Loss) in its own factory with a vertically integrated supply chain: this product ships in 12–18 weeks (new UL or CSA certification can extend that, within a guaranteed 36-week worst case), and every Entogo product carries a minimum 36-month manufacturer warranty. This **three-dimensional (triangular) wound-core transformer** winds a continuous ribbon into a closed, symmetric core, giving all three phases an equal magnetic path. The result is lower no-load loss, balanced excitation, low audible noise and a 15.7 % larger coil pressed area than a flat / stacked-core design for stronger short-circuit withstand — positioned as an efficiency upgrade to a conventional distribution transformer. It is available oil-filled as a pad-mounted unit (designed to **IEEE C57.12.34**) or as a dry-type unit (**UL 1561 / 1562**), in **15 / 25 / 35 kV class** to 480 / 208 V at 60 Hz, with an amorphous core option for the lowest standby loss. The core-and-coil meets **DOE 10 CFR 431** efficiency; UL (cULus) / CSA certification is available on request. ## Key features - Three-dimensional triangular wound core gives a symmetric, continuous magnetic path — lower no-load loss and balanced three-phase excitation. - Positioned as an efficiency upgrade to a conventional stacked-core unit; clears DOE 10 CFR 431 and suits loss-evaluated bids. - Continuous wound ribbon minimizes vibration and audible noise. - 15.7 % larger coil pressed area than flat-type cores raises short-circuit withstand. - Available oil-filled (pad-mounted, IEEE C57.12.34) or dry-type (UL 1561 / 1562), 60 Hz — UL (cULus) / CSA certification available on request. Custom-engineered · built to order [Get a quote](https://entogo.ca/products/transformer-quote/?from=Three-Dimensional%20Wound-Core%20Transformer%20(Low-Loss)) Lead time 12–18 weeks Order now for estimated delivery Dec 2026 – Jan 2027. Certification / testing may extend this per the standard and scope. Quality & certifications - ![UL safety certification mark](https://entogo.ca/_astro/Entogo-UL-Underwriters-Laboratories-North-America-Safety-Certification.BoQ45DeX_248O3C.webp) - ![CSA certification mark](https://entogo.ca/_astro/Entogo-CSA-Canadian-Standards-Association-Safety-Certification.CY1FySDR_Z11vFCD.webp) - ![CE European Conformity marking](https://entogo.ca/_astro/Entogo-CE-European-Conformity-Marking.xJPMJKcl_1wU1NT.webp) - ![ISO 9001 quality management mark](https://entogo.ca/_astro/Entogo-ISO-9001-Quality-Management-System-Certification.DbscJvvM_47kvy.webp) - ![ISO 14001 environmental management mark](https://entogo.ca/_astro/Entogo-ISO-14001-Environmental-Management-System-Certification.DXOTPjd4_Z4rpDm.webp) - ![IEC CB Scheme mark](https://entogo.ca/_astro/Entogo-CB-Scheme-IEC-International-Electrical-Certification.CPXJ4xZK_aV0YT.webp) Built under audited ISO quality systems and to ANSI/IEEE & IEC standards. Product-level UL (cULus) / CSA certification available on request. [See all certifications](https://entogo.ca/certifications/) ## Specifications Three-Dimensional Wound-Core Transformer (Low-Loss) specifications | Specification | Value | | --- | --- | | Applicable standards | IEEE C57.12.00 / .34 (oil) or UL 1561 / 1562 (dry) · DOE 10 CFR 431 | | Core | Three-dimensional (triangular) wound — symmetric, closed magnetic path | | Variants | Oil-filled pad-mounted, or dry-type (amorphous core optional) | | Voltage class | 15 / 25 / 35 kV class → 480 / 208 V LV | | Frequency | 60 Hz | | No-load loss | Lower than equivalent stacked-core design | | Three-phase balance | Symmetric — equal magnetic path on all three legs | | Coil pressed area | +15.7 % vs flat / stacked-core arrangements | | Efficiency | DOE 10 CFR 431 compliant | Glossary: [Wound-core](https://entogo.ca/glossary/#wound-core-transformer) [60 Hz vs. 50 Hz](https://entogo.ca/glossary/#60-hz-vs-50-hz) [Voltage class](https://entogo.ca/glossary/#voltage-class) ## Applications - Distribution networks and grid efficiency upgrades - Commercial and industrial power - Loss-evaluated utility and LEED projects Sizing & protection Size this transformer and its overcurrent protection before you request a quote — full-load current, primary/secondary OCPD (NEC 450.3(B) / CEC Section 26), available fault current for downstream AIC / SCCR, and a NEMA enclosure. [Open the sizing calculator](https://entogo.ca/tools/transformer-sizing-calculator/) Payment & financing Flexible payment and project financing is available for qualified projects — milestone-based plans, reduced upfront terms and third-party financing. Entogo is the equipment supplier, not a lender; all options are subject to credit review and a signed agreement. [See payment options](https://entogo.ca/payment-options/) After-sales Backed by Entogo lifecycle service — technical support, spare parts and a minimum 36-month warranty (well beyond the industry norm; up to 10 years on major power equipment, confirmed per contract). Our team responds to every request within one business day. [After-sales support](https://entogo.ca/support/) [Track an order](https://entogo.ca/support/order-status/) FAQ ## Common questions - **What is the advantage of a three-dimensional wound core?**: The triangular wound core gives all three phases an equal, closed magnetic path, which lowers no-load loss, balances excitation current and reduces audible noise versus a conventional stacked (flat) core — useful where no-load losses are evaluated in the bid. - **Is it available oil-filled or dry-type?**: Both. It is offered as an oil-filled pad-mounted unit (designed to IEEE C57.12.34) or as a dry-type unit (UL 1561 / 1562), 60 Hz, in 15 / 25 / 35 kV class — with an amorphous core option for the lowest standby loss. Power Equipment ## Related products [![Entogo three-phase pad-mounted distribution transformer, dead-front, NEMA 3R enclosure](https://entogo.ca/_astro/Entogo-10kV-Three-Phase-Oil-Immersed-Distribution-Transformer.MmNE1ATv_Z1W8tN.webp) Power Equipment ### 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. View](https://entogo.ca/products/three-phase-pad-mounted-transformer/)[![Entogo 36 kV outdoor compact unit substation for renewables and industrial sites](https://entogo.ca/_astro/Entogo-35kV-Chinese-Type-Substation.Dvb2rMnE_Z1wVTEq.webp) Power Equipment ### 36 kV Outdoor Compact Unit Substation A factory-assembled outdoor unit substation — incoming 34.5 / 35 kV switchgear, liquid-filled step-up or step-down transformer (1,000 – 10,000 kVA) and a low-voltage section in one weather-tight enclosure — for solar PV, wind, and industrial interconnection. Built to IEEE C37.121, ANSI C57.12.34 and IEC 62271-202. View](https://entogo.ca/products/outdoor-unit-substation-36kv/)[![Entogo amorphous-core high-efficiency dry-type transformer](https://entogo.ca/_astro/Entogo-SCBH15-Amorphous-Alloy-Dry-Type-Transformer.CfCVUmci_Z56Pvf.webp) Power Equipment ### Amorphous-Core Dry-Type Transformer (High-Efficiency) A high-efficiency amorphous-metal-core dry-type transformer with very low no-load loss, low noise and low partial discharge — 30–2500 kVA, medium voltage to 35 kV class stepping to 480/208 V, fire-safe. Designed to UL 1562, CSA C9/C802.2 and DOE 10 CFR 431; UL/CSA certifiable. View](https://entogo.ca/products/amorphous-core-dry-type-transformer/) ## Structured data (JSON-LD) ```json {"@context":"https://schema.org","@type":"Product","@id":"https://entogo.ca/products/wound-core-distribution-transformer/#product","url":"https://entogo.ca/products/wound-core-distribution-transformer/","name":"Three-Dimensional Wound-Core Transformer (Low-Loss)","description":"A three-dimensional (triangular) wound-core distribution transformer with a closed, symmetric core for lower no-load loss, balanced flux, low noise and high short-circuit withstand — oil-filled or dry-type, 15/25/35 kV class, 60 Hz. 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