Rio Grid

Four core lines. One factory schedule.

Every unit is built and tested to IEEE C57.12.00 and C57.12.90 and ships with certified routine test reports. Datasheets below are the submittal-ready versions; send the specification and we return drawings within 10 business days of order.

RG-A

Three-phase pad-mount transformers, 15 kV class

The workhorse for utilities, cooperatives, oilfield pads, and outdoor data center unit substations. Dead-front compartmental construction to IEEE C57.12.34 with loop-feed or radial-feed cabinets, mineral oil or FR3 natural ester.

  • Ratings500 to 5,000 kVA. Standard steps 500, 750, 1,000, 1,500, 2,000, 2,500, 3,000, 3,750, and 5,000 kVA. 75 to 300 kVA on request.
  • Primary voltage12,470Y/7,200 V, 13,200Y/7,620 V, or 13,800 V delta or wye. De-energized tap changer with four 2.5 percent taps, two above and two below rated.
  • Secondary voltage480Y/277 V standard. 208Y/120 V and 600 V available.
  • BIL95 kV high voltage standard, 125 kV option. 30 kV low voltage.
  • Impedance5.75 percent plus or minus 7.5 percent from 750 to 2,500 kVA. 2.0 percent plus or minus 10 percent at 500 kVA and below. 6.0 to 6.5 percent from 3,000 to 5,000 kVA.
  • Cooling and fluidONAN with mineral oil per ASTM D3487 Type II, or KNAN with FM Approved FR3 natural ester.
  • Temperature rise65 C standard. 55 C or 55/65 C dual rating for 50 C maximum ambient.
  • ConstructionDead-front compartmental cabinet per C57.12.34. Loop feed with six bushing wells and parking stands; radial feed available. Gang-operated under-oil load-break switch. Bayonet expulsion fuses in series with partial-range current-limiting fuses. Sealed tank rated 7 psig. Coating system per C57.12.28. Mild steel or 304 stainless cabinet.
  • Harmonic ratingK-4 to K-13 available; K-19 on request.
  • AccessoriesLiquid-level gauge, dial thermometer, pressure-vacuum gauge, pressure relief device, drain valve with sampler, bar-coded nameplate. Internal fault indicator optional.
  • StandardsIEEE C57.12.00, C57.12.90, C57.12.34, C57.12.28, IEEE 386. DOE 10 CFR 431 efficiency. NEMA TR 1 sound levels. FM 3990 on FR3-filled units.
  • Lead time12 to 16 weeks after drawing approval.
Download datasheet (PDF) Request a quote
RG-B

35 kV class pad-mount and inverter step-up transformers

For utility-scale solar and battery storage collection systems at 34.5 kV, data centers distributing at 34.5 kV, and cooperatives at 24.9 kV. Dual low-voltage windings for central inverters, bidirectional ratings for BESS duty.

  • Ratings2,500 to 5,000 kVA. 3,200 and 4,480 kVA string-skid ratings.
  • Primary voltage34,500 V delta or 34,500GrdY/19,920 V. 24,940GrdY/14,400 V for cooperatives. Taps plus or minus two 2.5 percent steps.
  • Secondary voltage600 to 800 V, single or dual windings for central inverters. 800 V for string-inverter skids. 480Y/277 V station-service units.
  • BIL150 kV high voltage standard, 200 kV option. 60 kV low voltage.
  • Impedance5.75 percent plus or minus 7.5 percent two-winding. 7.5 percent three-winding. 8 percent on skid ratings.
  • Cooling and fluidONAN mineral oil or KNAN FR3 natural ester, rated to minus 40 C.
  • Temperature rise65 C standard. 55 C option for 50 C maximum ambient.
  • ConstructionDead-front loop feed per C57.12.34. Five-legged core. Electrostatic shield standard. Type 3R enclosure on skid units. Bayonet plus current-limiting fuses, under-oil surge arresters.
  • BESS dutyBidirectional rating with cycling thermal design. 600 A load-break switch, gauges with alarm contacts, Kirk-key interlock provisions, viewing and infrared windows.
  • Harmonic ratingK-4 to K-13 for inverter spectra; K-19 available.
  • StandardsIEEE C57.12.00, C57.12.90, C57.12.34, C57.159 (photovoltaic applications), C57.110. IEEE 2800 model data supplied for interconnection studies. DOE 10 CFR 431 where applicable.
  • Lead time12 to 16 weeks after drawing approval.
Download datasheet (PDF) Request a quote
RG-C

Data center unit substation transformers

FR3-filled units for indoor electrical rooms and outdoor yards, hardened for vacuum-breaker switching transients with one BIL class above standard. Built for repeat orders of 50 to 100 units per campus on a staged schedule.

  • Ratings1,000 to 12,000 kVA.
  • Primary voltage13,800 V and 34,500 V standard; 5, 15, 25, and 35 kV classes available. Externally operable de-energized tap changer.
  • Secondary voltage480Y/277 V standard. 415Y/240 V, 208Y/120 V, and medium-voltage secondaries to 13.8 kV available.
  • BILOne class above standard: 150 kV on 15 kV class, 200 kV on 35 kV class.
  • ImpedanceSet to the fault study. 5.75 percent standard; 6.5 to 8 percent available. Available fault currents above 100 kA accommodated.
  • Fluid and coolingFM Approved FR3 natural ester standard, fire point above 300 C; mineral oil on request. KNAN self-cooled; KNAN/KNAF with fans for forced-air ratings.
  • Temperature rise65 C standard. 55 C option.
  • ConstructionSnubber-free switching-transient design. Welded radiators. Sidewall high-voltage bushings. Molded epoxy low-voltage bushings with NEMA spades, or throat for close-coupled switchgear and busway. Skid base with lifting lugs. Mild steel or 304L stainless. Seismic qualification available.
  • MonitoringDial thermometer, liquid level, pressure-vacuum gauge, and pressure relief, all with alarm contacts. Dissolved-gas and digital monitoring provisions.
  • StandardsIEEE C57.12.00, C57.12.90, C57.12.36, C57.12.28, C57.12.29. FM 3990. NEMA TR 1. DOE 10 CFR 431 for ratings of 5,000 kVA and below with 600 V secondaries.
  • Lead time12 to 16 weeks after drawing approval. Campus orders staged by building.
Download datasheet (PDF) Request a quote
RG-D

Distribution substation and medium power transformers

10 to 60 MVA at 69 kV and 138 kV for data center campus substations, utility and cooperative distribution substations, and Permian compressor stations and gas plants.

  • Ratings10 to 60 MVA; to 100 MVA on request. Multi-stage ratings such as 30/40/50 MVA ONAN/ONAF/ONAF.
  • High voltage69 kV and 138 kV classes.
  • Low voltage12.47, 13.8, 24.9, or 34.5 kV.
  • BILPer IEEE C57.12.00 for the class: 350 kV at 69 kV class, 550 or 650 kV at 138 kV class.
  • Impedance7 to 12 percent to the application; about 11 percent typical on 20 to 40 MVA data center units.
  • Tap changingLoad tap changer per IEEE C57.131, plus or minus 10 percent in 32 steps, or de-energized tap changer.
  • Cooling and fluidONAN/ONAF with mineral oil or natural ester. Sealed tank with nitrogen blanket or conservator.
  • ConstructionOutdoor substation construction. Cover-mounted bushings, detachable radiators, surge arrester brackets, current transformers for protection and metering.
  • MonitoringWinding and top-oil temperature, liquid level, pressure relief, sudden-pressure relay, dissolved-gas monitor provisions.
  • StandardsIEEE C57.12.00, C57.12.90, C57.12.10, C57.131, C57.91, C57.104. Built to RUS Bulletin 50-91 (S-3) on request for cooperatives.
  • Lead time26 to 40 weeks after drawing approval.
Download datasheet (PDF) Request a quote

Also supplied

  • Generator step-up transformers, 50 to 300 MVA at 138 kV and 345 kV for solar, storage, and behind-the-meter generation. Lead time quoted per project.
  • Dry-type transformers, cast resin and VPI, 300 kVA to 20 MVA at 15 and 35 kV class, UL 1562 Listed. Low-voltage K-13 PDU transformers 150 to 1,250 kVA.
  • Oilfield specialty: ESP multitap step-ups 100 to 540 kVA, skid-mounted unit substations 2.5 to 10 MVA, 12-pulse drive isolation units.
  • Single-phase distribution, pole and pad-mount 10 to 167 kVA, 7.2/12.47 kV and 14.4/24.9 kV.
  • Switchgear and e-houses, 15 and 35 kV metal-clad and pad-mount switchgear, packaged through our partners.

Have a specification? Send it with the need-by date.

Request a quote