SOLUTIONS: Specialty Transformers (Design & Manufacturing)


Ideal for oil and gas down-hole applications and other harsh industrial environments.

Southwest Electric’s Specialty Transformer Division is focused on the design and manufacturing of standard and custom designed,  small to mid-size liquid-filled transformers (including distribution and pad-mount transformers ) from 25kVA up to 5000 kVA.   Southwest can also deliver transformers as part of skid package, designed for quick set-up or relocation. The skid package can include a protective enclosure, a conditioned control room, switchgear, metering, reactors, lightning, and other desired features.  Southwest can also provide integration into a complete power distribution system.



Applications environments include:
· Oil and Gas down-hole and submerged pumps with variable speed drives
· Surface pumps
· Small utilities requiring distribution style transformers
· Industrial clients

Standard and Custom Design, liquid filled transformers: Our team of mechanical and electrical engineers is available to respond efficiently to your specific needs, with both standard and custom designs and configuration or manufacturing requirements, with strict testing and quality control measures. (We will design and test to meet all common industry standards including IEEE, NEMA, and ANSI as requested.)


· Average RFQ response time: 48 hours
· Average lead time for standard product: 3-5 business days (finished goods inventory, standard stock and JIT mfg will often minimize lead times)
· Average delivery time for custom product: varies by product complexity

Southwest Electric Company has a dedicated manufacturing facility for custom transformers with nearly 100,000sq feet of space, and an extensive array of testing and manufacturing equipment that includes:

  •  Dedicated coil sizing oven
  • 1.6MV, 80 kJ impulse generator
  • Haefely HIAS 743-2 digital impulse analyzing system
  • 350 kV dedicated hipot transformer
  • 180 Hz synchronous M-G set



Standard and custom transformers that Southwest designs and manufactures include:
• 25 kVA single phase through 5000 kVA three-phase (including full-amp capacity and polygon)
• Designs for 50 or 60 Hz, high harmonic conditions, extreme ambient temperatures and harsh environments.
• 600 V through 34,500 V class

For complete details, please view our models differentiated below.




  • 25 kVA single phase through 5000 kVA three phase
  • 480 volt through 69kV class
  • Designs for non-standard frequencies
  • Designs for high harmonic conditions
  • Transient suppression
  • Mineral oil or high fire-point insulating fluid
  • Designs for extreme conditions:
    • Extreme ambient temperatures
    • Hazardous locations
    • High altitudes
    • Paint systems for severe environments
  • Other features to your specifications as well as the leading industry standards:

Multi-Tap Transformers - FACT® Series

The FACT® (full amp capacity transformers) series is a broad line of single-phase and three-phase distribution-style transformers primarily designed for the rigorous duties of down-hole submersible pumps, as well as surface pumps, and Variable Speed Drive applications. The FACT® series provides full amp capacity across a wide secondary tapping range with 25 externally selectable positions.

SINGLE PHASE:   Single phase step-down FACT® transformers are available with single primary voltages (FACT® 125) or dual primary voltages (FACT® 225).

THREE-PHASE:  Our FACT® III series are three-phase step-up designs with a 480 V primary.



Soft Starter Reactor 

Designed for the starting of large motors, this device is designed to detect and respond to voltage drops. The SOFT STARTER incorporates a vacuum contactor and timing circuits for auto bypass of the reactor after the motor achieves full speed, and features a tap switch to match the reactance to the application.

Phase Shifting Transformers -Reduce the need for expensive harmonic filters .

Requires a multi-pulse input to operate. Our phase shifting transformers convert the three-phase utility voltage to provide the 12, 18, 24, or higher pulses required to feed modern multi-pulse variable frequency drives (VFD). The use of multi-pulse VFDs reduces the need for expensive harmonic filters. Our phase shifting transformers are sized to match the size of the VFD and the FACT® multi-tap transformer connected to its output, and come in a variety of models.

  • Poly-Auto Transformer – A 12-Pulse phase-shifting transformer, this polygon auto transformer is designed to supply a twelve-pulse motor drive, and reduces the need for expensive harmonic filters.
  • 18 and 24-pulse models (and higher)  also available as custom designs