The Evenson Power Pole Mounted Transformer is a rugged, oil-immersed distribution unit engineered for overhead lines, stepping medium voltage down to usable utilization levels.
Evenson Power Pole Mounted Transformers sit at the heart of overhead distribution networks, converting medium-voltage primary power into the lower voltages that residences, small commercial premises, and rural loads actually consume. Mounted directly on a utility pole or crossarm, the transformer keeps energized equipment well above ground level, away from people, vehicles, and floodwater, while remaining easy for line crews to access for inspection and replacement.
Every unit in the Evenson Power range is designed around a simple objective: deliver clean, stable power with the lowest possible losses, for the longest possible service life, in the harshest field conditions. From sub-zero winters to desert heat, from coastal salt-fog to dusty agricultural corridors, these transformers are specified to perform without intervention for decades.
A pole mounted transformer is a distribution-class transformer fixed to an overhead pole that reduces primary distribution voltage (commonly in the 4 kV to 34.5 kV class) to secondary service voltages such as 120/240 V for single-phase loads or 208Y/120 V and 480Y/277 V for three-phase loads. The Evenson Power design uses a sealed steel tank filled with insulating fluid that simultaneously cools the active part and provides high dielectric strength.
Single-phase units are the workhorse of residential and rural feeders. For three-phase loads, Evenson Power offers both integral three-phase tanks and banks of three single-phase units connected together, giving utilities flexibility in stocking and field assembly.
The active part comprises a high-permeability grain-oriented silicon-steel core and copper or aluminum windings. The core is built from precision-cut, low-loss laminations to minimize no-load (excitation) losses, while the windings are wound and braced to resist the mechanical forces produced during through-faults and inrush.
The core-and-coil assembly is housed in a robust, welded steel tank engineered to withstand weather, ultraviolet exposure, ice loading, and physical impact, including incidental animal contact. The tank also serves as the primary heat-dissipation surface, transferring losses to the surrounding air by natural convection and radiation. A weather-resistant finish protects against corrosion across the full service life.
Key external components include high-voltage and low-voltage bushings with high-grade porcelain or polymer insulation and grading hardware, an externally operable tap changer for voltage adjustment, lifting and mounting provisions, and a sealed-tank or conservator arrangement that accommodates the thermal expansion and contraction of the insulating fluid while a silica-gel breather keeps absorbed moisture out.
Evenson Power Pole Mounted Transformers are offered from 5 kVA up to 333 kVA per unit, spanning the full spectrum of single-phase residential service through to substantial three-phase commercial and light-industrial loads. Primary voltage classes extend up to 34.5 kV, with standard high-voltage taps for matching real-world feeder conditions and compensating for line voltage drop.
Standard frequency options of 50 Hz and 60 Hz are available to suit any regional grid. Insulation levels (BIL) are coordinated with the system voltage class to ensure surge withstand capability, and impedance values are selected to balance fault-current limitation against voltage regulation.
The Completely Self-Protected (CSP) variant integrates overload and secondary protection, internal expulsion or current-limiting fusing, and surge arresters directly onto the transformer, reducing the number of pole-top devices and simplifying installation. The Conventional variant is more economical where utilities prefer to coordinate protection with external cutouts and arresters.
Low core and load losses translate directly into lower operating cost and reduced carbon footprint over the transformer’s life. The sealed, oxygen-free design slows insulating-fluid degradation, extending service life and reducing maintenance frequency.
These transformers serve residential subdivisions, individual homes and farmsteads, commercial buildings, and light-industrial sites. They are a mainstay of rural electrification programs where long overhead feeders demand robust, low-maintenance equipment.
They are equally suited to distributed renewable energy integration, stepping the output of pole-adjacent solar and small wind installations to grid-compatible levels, and to street lighting, irrigation pumping, and telecommunications supply.
Every Evenson Power Pole Mounted Transformer is designed and tested to internationally recognized standards governing distribution transformers, covering ratings, losses, insulation coordination, and dielectric performance. Each unit undergoes routine factory tests including winding resistance, turns ratio, no-load and load loss measurement, impedance, applied-voltage and induced-voltage dielectric tests, and insulation-resistance verification.
Type and special tests such as temperature-rise, lightning-impulse, and short-circuit withstand are available to confirm performance to the product class. Certification marks supported across the range include UL, CE, KEMA, TUV, and IEC compliance.
Installation is straightforward: the transformer is hoisted and clamped to the pole or crossarm, the HV bushings are connected to the primary through cutouts and arresters, and the LV bushings feed the service drop. Mounting lugs and lifting eyes are provided as standard.
Maintenance is minimal thanks to the sealed design. Recommended practice includes periodic visual inspection of bushings and tank for leaks or corrosion, checking the silica-gel breather color where fitted, and periodic sampling of the insulating fluid for dielectric strength, moisture, and acidity on larger units. Tap positions should only be changed with the unit de-energized.
Evenson Power combines proven distribution-transformer engineering with rigorous quality control to deliver units that utilities and contractors can specify with confidence. Low losses, long sealed-tank life, and flexible CSP or Conventional configurations mean lower total cost of ownership and fewer field interventions.
Backed by responsive technical support and a commitment to consistent build quality, Evenson Power Pole Mounted Transformers are built to keep the lights on, year after year, in the most demanding overhead environments.
| Type | Oil-immersed, pole-mounted distribution transformer |
| Power Rating | 5 kVA – 333 kVA |
| Primary Voltage Class | Up to 34.5 kV |
| Secondary Voltage | 120/240 V, 208Y/120 V, 480Y/277 V (others available) |
| Phases | Single-phase / three-phase |
| Frequency | 50 Hz / 60 Hz |
| Cooling | ONAN (oil natural, air natural) |
| Core Material | Grain-oriented silicon steel (CRGO) |
| Winding Material | Copper or aluminum |
| Insulating Medium | Mineral / ester insulating fluid |
| Tap Changer | De-energized, typ. +/-2 x 2.5% |
| Configuration | CSP (Completely Self-Protected) or Conventional |
| Bushings | Porcelain or polymer, with grading hardware |
| Standards | IEC / UL / CE / KEMA / TUV |
| Design Life | 30+ years |
| Enclosure | Welded steel tank, corrosion-protected outdoor finish |
Engineered, certified and delivered under the Evenson Power name.
