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Equipment/3-phase pad-mount

DISTRIBUTION

3-phase pad-mount transformers

Custom-built distribution transformers for data centers, industrial facilities, solar projects, utilities, and commercial developments.

100–10,000 kVACAPACITY RANGE
Up to 35 kVVOLTAGE
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Built to IEEE / ANSI
standards
Three-phase pad-mounted transformer, front view with external radiator panels BUILT AROUND YOUR SPECIFICATION
Three-phase pad-mounted transformer, front view with external radiator panels Three-phase pad-mounted transformer with front access cabinet Three-phase pad-mounted transformer, rear side view with cooling radiator Open three-phase pad-mounted transformer showing primary and secondary sections

THE RIGHT EQUIPMENT

Dependable power for demanding loads.

Engineered to help you buy with confidence and execute projects smoothly, from PO to commissioning. Each design prioritizes thermal efficiency, mechanical strength, and electrical reliability, with a minimum K-4 rating, for long service life in demanding environments.

HIGHER THERMAL CLASS, AS STANDARD

ANSI base standard105°C
supertran specifies120 / 140°C

Cooler operation, higher ambient tolerance, and greater continuous loading, well suited to solar generation, motor-driven loads, and data centers. Paired with FR3 fluid, it helps extend transformer life and improve overload capability.

Why thermal class matters
Application-specific technical review Strict quality control at every production stage Warranty covering materials & workmanship U.S.-based service, technical & warranty support Top-tier quality without the premium price tag

AT A GLANCE

Technical specifications

SpecificationDetails
Power rating100–10,000 kVA
Voltage classUp to 35 kV
Design standardsIEEE / ANSI
Thermal class options120°C / 140°C
K-factor ratingK-4 standard; K-9 / K-13 available
Insulating fluidType II mineral oil or FR3
Winding materialAluminum or copper
CoolingONAN / ONAF or KNAN / KNAF

Ranges describe available configurations. Final ratings, standards, accessories, and delivery are confirmed for your project.

CONFIGURED FOR YOUR APPLICATION

Design options & accessories

Core & windings
StandardOption
3-legged coreShort-circuit strength5-legged coreWye/Wye advantages
Cylindrical windingsShort-circuit strengthElliptical windingsSmaller tank
Mitered coreLow lossesWound coreWye/Wye advantages
Aluminum windingsLower costCopper windingsSmaller tank
K-4 ratingHandles harmonicsK-9 or K-13 ratingFor higher harmonic loads. See K rating guide
Two windingsIsolation transformer3, 4, or 5 windingsLower secondary amps; drives and special applications
Tank, radiators & bushings
StandardOption
Painted mild steelPanel-type radiators for coolingGalvanized or stainlessBetter corrosion resistance
Welded radiatorsFixed to the tankValved, removable radiatorsEasier maintenance planning; may be required for shipping
Dead-front HV bushingsConnections at ground potential for personnel safetyLive-front HV bushingsExposed bushing connections
Fluid & cooling
StandardOption
Type II non-PCB mineral oilONAN cooling; lowest costFR3 natural ester (vegetable oil)KNAN cooling; high flash point
ONAN, mineral oilBase kVA with oil and ambient airONAN/ONAFFans increase the maximum kVA
KNAN, FR3Base kVA with FR3 and ambient airKNAN/KNAFFans increase the maximum kVA
Fusing & switching
StandardOption
Bay-O-Net fuses with isolation linkOver-current protection with a safety feature for linemenBay-O-Net fuses with current-limiting fusesOver-current protection plus current-limiting fuses for internal fault protection
2-position HV load-break switchRadial feed: on / off4-position HV load-break switchLoop feed: feed left, feed right, feed through, off
Included as standard
  • Standard taps5 taps at 2.5% each: 2 above and 2 below nominal
  • Oil temperature, oil level & pressure/vacuum gaugesMounted in the LV compartment
  • Nitrogen fill portFor adding nitrogen
  • Drain / sample valve
  • Oil drip panBelow the fuses, to reduce the risk of oil on bushings
Optional features & accessories
  • Fan coolingONAN/ONAF or KNAN/KNAF for higher capacity and cooler running. Not for use in unsecured public areas.
  • LV cable supportsSupport for heavy cables; standard on 12-hole spades
  • Sudden pressure rise relay
  • Cover-mounted pressure release device
  • Special HV tapsK taps (12, 12.47, 13.2, 13.8, 14.4 kV) or 7 taps, within a total 20% voltage range
  • Electrostatic shieldMitigates voltage transients and anomalies generated to the source. Common with K-rated and drive isolation transformers.
  • Gauges with contactsOil level, oil temperature, and pressure/vacuum gauges wired to an external control box
  • External boxesLockable box for gauges and sample port, control box for gauges and nitrogen port, or a box for the oil sample valve

SIZING FOR HARMONICS

K rating information to consider.

Every unit is K-4 rated as standard, with K-9 and K-13 designs for heavier harmonic loads. K-9 is commonly used for 6-pulse drives.

Values are for quick reference. We can help determine the right K rating for your loads and system configuration. Additional K rating improves efficiency in most cases.

Ask an engineer
Load typeRecommended K factor
According to IEEE C57.110
Computer data centers3.5–4
UPS systems3.0–3.8
Fluorescent lighting2.0–2.5
According to IEC 60076-7
Variable frequency drives4.0–5.5
Arc furnaces5.0–6.5
Industrial drives4.0–5.0

START YOUR SPECIFICATION

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your fit.

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