Distribution Transformer

The Evenson Power Distribution Transformer performs the final, customer-facing stage of voltage transformation in the power system, stepping medium-voltage primary supply down to the low-voltage levels used by end users. It is one of the most widely deployed pieces of equipment on any electrical network, found on utility poles, on concrete pads, and inside electrical rooms across residential, commercial, and industrial settings.

Beyond simply lowering voltage, the distribution transformer regulates voltage, provides electrical isolation between primary and secondary circuits, and reduces energy losses in local delivery. Evenson Power builds each unit for efficiency, durability, and safe, dependable everyday operation.

A distribution transformer is a relatively low-capacity power transformer that converts primary distribution voltage into the secondary utilization voltage delivered to customers. Typical primary voltages range from about 2.4 kV to 35 kV, while secondary outputs commonly range from 120/208 V single- or three-phase up to 2,400 V depending on the application.

Operating continuously and often lightly loaded for much of the day, distribution transformers are designed for high efficiency and long life. They are produced in single-phase and three-phase versions and in pole-mounted, pad-mounted, and enclosed configurations to suit different installation environments.

Dry-type designs using cast-resin or VPI insulation are available for indoor and fire-sensitive locations. The sealed-tank construction protects the active part from moisture and contamination, supporting a long, maintenance-light service life.

• Laminated silicon-steel core with copper or aluminum windings
• Oil-impregnated paper insulation in a sealed or breathing tank
• Mineral or vegetable insulating oil (dry-type options available)
• Porcelain or composite HV/LV bushings
• Off-circuit tap changer for voltage regulation

Evenson Power distribution transformers cover a broad capacity range from roughly 25 kVA up to 5,000 kVA, with small pole-mounted single-phase units typically in the 16–100 kVA range and larger three-phase pad-mounted units serving commercial and light-industrial loads. Voltage class for distribution duty is up to 35 kV on the primary side.

Single-phase units are widely used for residential and rural service, while three-phase units supply commercial buildings, industrial equipment, and multi-tenant developments. Each transformer is configured to the exact primary and secondary voltages required at its location.

• Steps down and regulates voltage for safe end use
• Provides electrical isolation between primary and secondary
• Low core and load losses for energy-efficient delivery
• Single- and three-phase, pole- and pad-mounted configurations
• Sealed-tank design resists moisture and contamination
• Long service life of 20 to 40 years

Distribution transformers are deployed anywhere medium-voltage supply must be converted to usable low voltage. On utility networks they serve residential neighborhoods, rural lines, and street-level distribution from poles and pads. In commercial and institutional settings they supply offices, retail centers, schools, and hospitals.

Industrial facilities rely on them to feed machinery, lighting, and process equipment, and they are equally common in agricultural, municipal, and infrastructure applications where dependable final-stage power conversion is essential.

• Residential and rural utility service
• Commercial buildings, retail, and institutional facilities
• Industrial machinery, lighting, and process loads
• Agricultural, municipal, and infrastructure power

Evenson Power distribution transformers are manufactured and tested to IEC, IEEE/ANSI, NEMA, UL, CE, and DOE efficiency standards. Routine factory testing includes turns ratio, winding resistance, insulation resistance, polarity, dielectric withstand, no-load loss, and load loss, ensuring each unit meets its rated efficiency and performance before shipment.

Documented test reports accompany every transformer, and additional type or special testing is available for projects with specific qualification needs.

Pole-mounted units are hung on utility structures and connected to overhead primary and secondary conductors, while pad-mounted and enclosed units are placed on prepared pads or in electrical rooms and connected to underground or in-building cabling. Proper grounding and clearances are observed in all cases, and commissioning checks confirm correct voltage, polarity, and protection before energization.

Distribution transformers are inherently low-maintenance. Evenson Power recommends annual visual inspections, with more thorough maintenance and oil checks every five to ten years. Routine attention to bushings, oil level and quality, connections, and signs of overheating keeps units operating reliably for their full service life.

• Pole-, pad-, or room-mounted with proper grounding and clearances
• Commission voltage, polarity, and protection before energizing
• Inspect annually; perform major maintenance every 5–10 years
• Check oil level/quality, bushings, and connections routinely

Evenson Power distribution transformers combine efficient, low-loss design with rugged construction and dependable, low-maintenance operation. Each unit is built to its exact service voltages and tested to recognized standards, then backed by knowledgeable support. For utilities, developers, and facility owners who need reliable last-stage power conversion that simply works, Evenson Power is a brand to build on.

Evenson Power distribution transformers in the 11/0.4kV class are built under a controlled quality system in which every stage, from core stacking and winding to tanking and oil filling, is inspected and recorded. Incoming materials such as electrical steel, copper or aluminium conductor, and insulating oil are verified against specification before they enter production, ensuring consistent magnetic and dielectric performance across every batch.

Each completed unit is routine-tested for voltage ratio, polarity and vector group, winding resistance, no-load loss and current, load loss and impedance, and separate-source and induced overvoltage withstand. Sample units from each design are subjected to temperature-rise and short-circuit withstand type tests to confirm thermal and mechanical robustness under fault conditions. Oil samples are checked for breakdown voltage and moisture content prior to dispatch.

All test results are documented on a serialized test certificate supplied with the transformer, giving utilities and contractors full traceability from raw material to finished product.

• 100% routine testing of every unit
• Verified electrical steel and conductor on incoming inspection
• Type-tested for temperature rise and short-circuit withstand
• Oil breakdown and moisture verification before dispatch
• Serialized test certificate for full traceability

Designed for a service life well in excess of thirty years, Evenson Power distribution transformers require only modest, predictable maintenance. Hermetically sealed and conservator variants both minimize oil exposure to atmosphere, slowing oxidation and moisture ingress. Periodic checks of oil level, bushing condition, and surface temperature, combined with routine dissolved gas and dielectric oil sampling, allow operators to track ageing and intervene before faults develop.

The low-loss core and high-grade insulation system are specified to run cool at rated load, which directly extends insulation life and reduces thermal stress during overload events. External surfaces are finished with a durable corrosion-resistant coating system suited to outdoor pole-mounted and ground-mounted duty, and tank designs are leak-tested to ensure long-term sealing integrity.

Evenson Power supplies spare parts, replacement bushings, and oil reconditioning guidance, and can advise on condition-based maintenance schedules tailored to network loading and ambient conditions.