Delta Star’s mobile substations serve as turnkey solutions designed and manufactured to comply with customer specifications and DOT requirements. Our mobile transformers and mobile substations can be used for a number of different purposes, including:

  • Emergency Service
  • Routine Maintenance
  • Temporary Power Supply and Substation Capacity Increases
  • Power for Seasonal Load

Scope & Capabilities


Type MVA (Top Rating) HV kV
Mobile Substations <100 25-230
Auto Transformer <100 15-230
Voltage Regulator 7 5-69
HV Circuit Switcher Trailer <230
HV Breaker Trailer <230
LV Breaker Trailer <69
Cable Reel Trailer
Capacitor Bank Trailer



  • Each mobile substation is assembled in the plant where the transformer is manufactured
  • Fully assembled mobile units are energized at rated voltage before leaving manufacturing plants
  • Trailer, transformers and all major components are manufactured and tested in the United States
  • Mobiles are designed to meet state and federal highway requirements

Trailer Mounted Substations

Delta Star has over 110 years in the power industry and over 40 years manufacturing auxiliary trailers. We pride ourselves in providing our customers with quality auxiliary trailers including circuit switchers, breakers, breakers with a switch, transrupters with a switch, cable reel, and security fence trailers.

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Mobile Repair

Delta Star has industry leading experience in the repair and redesign of all types of transformers, servicing any manufacturer on voltage classes up to 230 kV. Our engineering and  manufacturing teams can remanufacture, repair and retrofit your aging equipment, either in the field or in the factory, to ensure it is fitted with the industry’s most recent materials and technologies.

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Delta Star Worker

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